Personality Disorder | Health Dictionary

Condition in which the individual fails to learn from experience or to adapt to changes. The outcome is impaired social functioning and personal distress. There are three broad overlapping groups. One group is characterised by eccentric behaviour with paranoid or schizoid overtones. The second group shows dramatic and emotional behaviour with self-centredness and antisocial behaviour as typical components of the disorder. In the third group, anxiety and fear are the main characteristics, which are accompanied by dependency and compulsive behaviour. These disorders are not classed as illnesses but psychotherapy and behavioural therapy may help. The individuals a?ected are notoriously resistant to any help that is o?ered, tending to blame other people, circumstances or bad luck for their persistent di?culties. (See MENTAL ILLNESS; MULTIPLE PERSONALITY DISORDER; MUNCHAUSEN’S SYNDROME.)


Personality Disorder | Health Dictionary

Keywords of this word: Personality Disorder


ATTENTION DEFICIT DISORDER (HYPERACTIVITY SYNDROME)

Medical Dictionary

A lifelong disorder characterised by overactive behaviour, short attention span and poor concentration. It is thought to be caused by a minor abnormality that a?ects the part of the brain that allows us to concentrate and focus on tasks. Some scientists have suggested that it may be caused by particular foods, particularly processed foods containing arti?cial additives, and recommend special diets. In some countries, attention de?cit disorder is diagnosed in up to a tenth of all children; this may re?ect di?erences in paediatric practice and diagnosis rather than a real variation in prevalence of the disorder. Behaviour therapy is the main treatment. Those children with very severe symptoms of restlessness, short attention span and disturbed behaviour may respond to additional treatment with methylphenidate (Ritalin®). This is an amphetamine-like drug that is thought to stimulate the part of the brain that is not working properly. Use of this drug has, however, been controversial.... Medical Dictionary

AUTOIMMUNE DISORDERS

Medical Dictionary

A collection of conditions in which the body’s immune system (see IMMUNITY) attacks its own tissues, identifying them as foreign substances. Genetic factors may play a part in this abnormal function, but the causes are not clear. The disorder may a?ect one organ (organ-speci?c) or type of cell, or several (non-organspeci?c). Among the autoimmune disorders are ADDISON’S DISEASE; autoimmune haemolytic anaemia and pernicious anaemia (see under ANAEMIA); autoimmune chronic active HEPATITIS; DIABETES MELLITUS; MYASTHENIA GRAVIS; RHEUMATOID ARTHRITIS; and SYSTEMIC LUPUS ERYTHEMATOSUS (SLE).

Treatment Any major de?ciencies, such as thyroxin or insulin lack, should be corrected. The activity of the immune system should then be reduced. CORTICOSTEROIDS and, in more severe cases, strong immunosuppressant drugs – AZATHIOPRINE, CYCLOPHOSPHAMIDE or METHOTREXATE – should be administered. Treatment is di?cult because of the need to control the autoimmune condition without damaging the body’s ability to combat other diseases.... Medical Dictionary

BIPOLAR DISORDER

Medical Dictionary

A type of mental illness typi?ed by mood swings between elation (mania) and depression (see MENTAL ILLNESS).... Medical Dictionary

BONE, DISORDERS OF

Medical Dictionary

Bone is not an inert sca?olding for the human body. It is a living, dynamic organ, being continuously remodelled in response to external mechanical and chemical in?uences and acting as a large reservoir for calcium and phosphate. It is as susceptible to disease as any other organ, but responds in a way rather di?erent from the rest of the body.

Bone fractures These occur when there is a break in the continuity of the bone. This happens either as a result of violence or because the bone is unhealthy and unable to withstand normal stresses.

SIMPLE FRACTURES Fractures where the skin remains intact or merely grazed. COMPOUND FRACTURES have at least one wound which is in communication with the fracture, meaning that bacteria can enter the fracture site and cause infection. A compound fracture is also more serious than a simple fracture because there is greater potential for blood loss. Compound fractures usually need hospital admission, antibiotics and careful reduction of the fracture. Debridement (cleaning and excising dead tissue) in a sterile theatre may also be necessary.

The type of fracture depends on the force which has caused it. Direct violence occurs when an object hits the bone, often causing a transverse break – which means the break runs horizontally across the bone. Indirect violence occurs when a twisting injury to the ankle, for example, breaks the calf-bone (the tibia) higher up. The break may be more oblique. A fall on the outstretched hand may cause a break at the wrist, in the humerus or at the collar-bone depending on the force of impact and age of the person. FATIGUE FRACTURES These occur after the bone has been under recurrent stress. A typical example is the march fracture of the second toe, from which army recruits su?er after long marches. PATHOLOGICAL FRACTURES These occur in bone which is already diseased – for example, by osteoporosis (see below) in post-menopausal women. Such fractures are typically crush fractures of the vertebrae, fractures of the neck of the femur, and COLLES’ FRACTURE (of the wrist). Pathological fractures also occur in bone which has secondary-tumour deposits. GREENSTICK FRACTURES These occur in young children whose bones are soft and bend, rather than break, in response to stress. The bone tends to buckle on the side opposite to the force. Greenstick fractures heal quickly but still need any deformity corrected and plaster of Paris to maintain the correction. COMPLICATED FRACTURES These involve damage to important soft tissue such as nerves, blood vessels or internal organs. In these cases the soft-tissue damage needs as much attention as the fracture site. COMMINUTED FRACTURES A fracture with more than two fragments. It usually means that the injury was more violent and that there is more risk of damage to vessels and nerves. These fractures are unstable and take longer to unite. Rehabilitation tends to be protracted. DEPRESSED FRACTURES Most commonly found in skull fractures. A fragment of bone is forced inwards so that it lies lower than the level of the bone surrounding it. It may damage the brain beneath it.

HAIR-LINE FRACTURES These occur when the bone is broken but the force has not been severe enough to cause visible displacement. These fractures may be easily missed. Symptoms and signs The fracture site is usually painful, swollen and deformed. There is asymmetry of contour between limbs. The limb is held uselessly. If the fracture is in the upper

limb, the arm is usually supported by the patient; if it is in the lower limb then the patient is not able to bear weight on it. The limb may appear short because of muscle spasm.

Examination may reveal crepitus – a bony grating – at the fracture site. The diagnosis is con?rmed by radiography.

Treatment Healing of fractures (union) begins with the bruise around the fracture being resorbed and new bone-producing cells and blood vessels migrating into the area. Within a couple of days they form a bridge of primitive bone across the fracture. This is called callus.

The callus is replaced by woven bone which gradually matures as the new bone remodels itself. Treatment of fractures is designed to ensure that this process occurs with minimal residual deformity to the bone involved.

Treatment is initially to relieve pain and may involve temporary splinting of the fracture site. Reducing the fracture means restoring the bones to their normal position; this is particularly important at the site of joints where any small displacement may limit movement considerably.

with plaster of Paris. If closed traction does not work, then open reduction of the fracture may

be needed. This may involve ?xing the fracture with internal-?xation methods, using metal plates, wires or screws to hold the fracture site in a rigid position with the two ends closely opposed. This allows early mobilisation after fractures and speeds return to normal use.

External ?xators are usually metal devices applied to the outside of the limb to support the fracture site. They are useful in compound fractures where internal ?xators are at risk of becoming infected.

Consolidation of a fracture means that repair is complete. The time taken for this depends on the age of the patient, the bone and the type of fracture. A wrist fracture may take six weeks, a femoral fracture three to six months in an adult.

Complications of fractures are fairly common. In non-union, the fracture does not unite

– usually because there has been too much mobility around the fracture site. Treatment may involve internal ?xation (see above). Malunion means that the bone has healed with a persistent deformity and the adjacent joint may then develop early osteoarthritis.

Myositis ossi?cans may occur at the elbow after a fracture. A big mass of calci?ed material develops around the fracture site which restricts elbow movements. Late surgical removal (after 6–12 months) is recommended.

Fractured neck of FEMUR typically a?ects elderly women after a trivial injury. The bone is usually osteoporotic. The leg appears short and is rotated outwards. Usually the patient is unable to put any weight on the a?ected leg and is in extreme pain. The fractures are classi?ed according to where they occur:

subcapital where the neck joins the head of the femur.

intertrochanteric through the trochanter.

subtrochanteric transversely through the upper end of the femur (rare). Most of these fractures of the neck of femur

need ?xing by metal plates or hip replacements, as immobility in this age group has a mortality of nearly 100 per cent. Fractures of the femur shaft are usually the result of severe trauma such as a road accident. Treatment may be conservative or operative.

In fractures of the SPINAL COLUMN, mere damage to the bone – as in the case of the so-called compression fracture, in which there is no damage to the spinal cord – is not necessarily serious. If, however, the spinal cord is damaged, as in the so-called fracture dislocation, the accident may be a very serious one, the usual result being paralysis of the parts of the body below the level of the injury. Therefore the higher up the spine is fractured, the more serious the consequences. The injured person should not be moved until skilled assistance is at hand; or, if he or she must be removed, this should be done on a rigid shutter or door, not on a canvas stretcher or rug, and there should be no lifting which necessitates bending of the back. In such an injury an operation designed to remove a displaced piece of bone and free the spinal cord from pressure is often necessary and successful in relieving the paralysis. DISLOCATIONS or SUBLUXATION of the spine are not uncommon in certain sports, particularly rugby. Anyone who has had such an injury in the cervical spine (i.e. in the neck) should be strongly advised not to return to any form of body-contact or vehicular sport.

Simple ?ssured fractures and depressed fractures of the skull often follow blows or falls on the head, and may not be serious, though there is always a risk of damage which is potentially serious to the brain at the same time.

Compound fractures may result in infection within the skull, and if the skull is extensively broken and depressed, surgery is usually required to check any intercranial bleeding or to relieve pressure on the brain.

The lower jaw is often fractured by a blow on the face. There is generally bleeding from the mouth, the gum being torn. Also there are pain and grating sensations on chewing, and unevenness in the line of the teeth. The treatment is simple, the line of teeth in the upper jaw forming a splint against which the lower jaw is bound, with the mouth closed.

Congenital diseases These are rare but may produce certain types of dwar?sm or a susceptibility to fractures (osteogenesis imperfecta).

Infection of bone (osteomyelitis) may occur after an open fracture, or in newborn babies with SEPTICAEMIA. Once established it is very di?cult to eradicate. The bacteria appear capable of lying dormant in the bone and are not easily destroyed with antibiotics so that prolonged treatment is required, as might be surgical drainage, exploration or removal of dead bone. The infection may become chronic or recur.

Osteomalacia (rickets) is the loss of mineralisation of the bone rather than simple loss of bone mass. It is caused by vitamin D de?ciency and is probably the most important bone disease in the developing world. In sunlight the skin can synthesise vitamin D (see APPENDIX 5: VITAMINS), but normally rickets is caused by a poor diet, or by a failure to absorb food normally (malabsorbtion). In rare cases vitamin D cannot be converted to its active state due to the congenital lack of the speci?c enzymes and the rickets will fail to respond to treatment with vitamin D. Malfunction of the parathyroid gland or of the kidneys can disturb the dynamic equilibrium of calcium and phosphate in the body and severely deplete the bone of its stores of both calcium and phosphate.

Osteoporosis A metabolic bone disease resulting from low bone mass (osteopenia) due to excessive bone resorption. Su?erers are prone to bone fractures from relatively minor trauma. With bone densitometry it is now possible to determine individuals’ risk of osteoporosis and monitor their response to treatment.

By the age of 90 one in two women and one in six men are likely to sustain an osteoporosis-related fracture. The incidence of fractures is increasing more than would be expected from the ageing of the population, which may re?ect changing patterns of exercise or diet.

Osteoporosis may be classi?ed as primary or secondary. Primary consists of type 1 osteoporosis, due to accelerated trabecular bone loss, probably as a result of OESTROGENS de?ciency. This typically leads to crush fractures of vertebral bodies and fractures of the distal forearm in women in their 60s and 70s. Type 2 osteoporosis, by contrast, results from the slower age-related cortical and travecular bone loss that occurs in both sexes. It typically leads to fractures of the proximal femur in elderly people.

Secondary osteoporosis accounts for about 20 per cent of cases in women and 40 per cent of cases in men. Subgroups include endocrine (thyrotoxicosis – see under THYROID GLAND, DISEASES OF, primary HYPERPARATHYROIDISM, CUSHING’S SYNDROME and HYPOGONADISM); gastrointestinal (malabsorption syndrome, e.g. COELIAC DISEASE, or liver disease, e.g. primary biliary CIRRHOSIS); rheumatological (RHEUMATOID ARTHRITIS or ANKYLOSING SPONDYLITIS); malignancy (multiple MYELOMA or metastatic CARCINOMA); and drugs (CORTICOSTEROIDS, HEPARIN). Additional risk factors for osteoporosis include smoking, high alcohol intake, physical inactivity, thin body-type and heredity.

Individuals at risk of osteopenia, or with an osteoporosis-related fracture, need investigation with spinal radiography and bone densitometry. A small fall in bone density results in a large increase in the risk of fracture, which has important implications for preventing and treating osteoporosis.

Treatment Antiresorptive drugs: hormone replacement therapy – also valuable in treating menopausal symptoms; treatment for at least ?ve years is necessary, and prolonged use may increase risk of breast cancer. Cyclical oral administration of disodium etidronate – one of the bisphosphonate group of drugs – with calcium carbonate is also used (poor absorption means the etidronate must be taken on an empty stomach). Calcitonin – currently available as a subcutaneous injection; a nasal preparation with better tolerance is being developed. Calcium (1,000 mg daily) seems useful in older patients, although probably ine?ective in perimenopausal women, and it is a safe preparation. Vitamin D and calcium – recent evidence suggests value for elderly patients. Anabolic steroids, though androgenic side-e?ects (masculinisation) make these unacceptable for most women.

With established osteoporosis, the aim of treatment is to relieve pain (with analgesics and physical measures, e.g. lumbar support) and reduce the risk of further fractures: improvement of bone mass, the prevention of falls, and general physiotherapy, encouraging a healthier lifestyle with more daily exercise.

Further information is available from the National Osteoporosis Society.

Paget’s disease (see also separate entry) is a common disease of bone in the elderly, caused by overactivity of the osteoclasts (cells concerned with removal of old bone, before new bone is laid down by osteoblasts). The bone a?ected thickens and bows and may become painful. Treatment with calcitonin and bisphosphonates may slow down the osteoclasts, and so hinder the course of the disease, but there is no cure.

If bone loses its blood supply (avascular necrosis) it eventually fractures or collapses. If the blood supply does not return, bone’s normal capacity for healing is severely impaired.

For the following diseases see separate articles: RICKETS; ACROMEGALY; OSTEOMALACIA; OSTEOGENESIS IMPERFECTA.

Tumours of bone These can be benign (non-cancerous) or malignant (cancerous). Primary bone tumours are rare, but secondaries from carcinoma of the breast, prostate and kidneys are relatively common. They may form cavities in a bone, weakening it until it breaks under normal load (a pathological fracture). The bone eroded away by the tumour may also cause problems by causing high levels of calcium in the plasma.

EWING’S TUMOUR is a malignant growth a?ecting long bones, particularly the tibia (calfbone). The presenting symptoms are a throbbing pain in the limb and a high temperature. Treatment is combined surgery, radiotherapy and chemotherapy.

MYELOMA is a generalised malignant disease of blood cells which produces tumours in bones which have red bone marrow, such as the skull and trunk bones. These tumours can cause pathological fractures.

OSTEOID OSTEOMA is a harmless small growth which can occur in any bone. Its pain is typically removed by aspirin.

OSTEOSARCOMA is a malignant tumour of bone with a peak incidence between the ages of ten and 20. It typically involves the knees, causing a warm tender swelling. Removal of the growth with bone conservation techniques can often replace amputation as the de?nitive treatment. Chemotherapy can improve long-term survival.... Medical Dictionary

CHRONIC DISORDER

Medical Dictionary

A persistent or recurring condition or group of symptoms. Chronic disorders are customarily contrasted with acute diseases which start suddenly and last a short time. The symptoms of acute disease often include breathlessness, fever, severe pain and malaise, with the patient’s condition changing from day to day or even hour to hour. Those su?ering from chronic conditions – for example, severe arthritis, protracted lung disease, ASTHMA or SILICOSIS – should be distinguished from those with a ‘static disability’ following a stroke or injury. Chronic disorders steadily deteriorate, often despite treatment and the patient is increasingly unable to carry out his or her daily activities.... Medical Dictionary

CONNECTIVE TISSUE DISORDERS

Medical Dictionary

A group of generalised in?ammatory diseases that a?ect CONNECTIVE TISSUE in almost any system in the body. The term does not include those disorders of genetic origin. RHEUMATIC FEVER and RHEUMATOID ARTHRITIS were traditionally classi?ed in this group, as were those diseases classed under the outdated heading COLLAGEN DISEASES.... Medical Dictionary

CONVERSION DISORDER

Medical Dictionary

A psychological disorder, also called hysterical conversion, in which the a?ected individual presents with striking neurological symptoms – such as weakness, paralysis, sensory disturbances or memory loss – for which no organic cause can be identi?ed. Up to 4 per cent of patients attending neurological outpatient clinics have been estimated as having conversion disorders. The disorder remains controversial, with theories about its cause unsupported by controlled research results. In clinical practice the physician’s experience and intuition are major factors in diagnosis. It has been suggested that the physical symptoms represent guilt about a physical or emotional assault on someone else. Treatment using a COGNITIVE BEHAVIOUR approach may help those with conversion disorders.... Medical Dictionary

DEGENERATIVE DISORDERS

Medical Dictionary

An umbrella description for a wide variety of conditions in which there is increased deterioration of the structure or function (or both) of the body. Ageing causes a steady degeneration of many tissues and organs – for example, wrinkling of the skin, CATARACT and poor neuromuscular coordination. In degenerative disorders the changes occur earlier in life. The nervous system, muscles, arteries, joints and eyes are all susceptible. Specialised tissues are replaced by CONNECTIVE TISSUE. The commonest example in the nervous system is ALZHEIMER’S DISEASE, which causes dementia; while in HUNTINGTON’S CHOREA, a genetic disorder, dementia is accompanied by incoordination of movements.... Medical Dictionary

DISSOCIATIVE DISORDER

Medical Dictionary

A collection of psychological disorders in which a particular mental function becomes cut o? from a person’s mind. Hysterical AMNESIA is one example, when the person forgets his or her personal history but can still absorb and talk about new events. Other examples are FUGUE, depersonalisation (detachment from self and environment), and MULTIPLE PERSONALITY DISORDER.... Medical Dictionary

EATING DISORDERS

Medical Dictionary

The term ‘eating disorders’ covers OBESITY, feeding problems in childhood, anorexia nervosa, and bulimia nervosa. The latter two are described here.

Anorexia nervosa Often called the slimmer’s disease, this is a syndrome characterised by the loss of at least a quarter of a person’s normal body weight; by fear of normal weight; and, in women, by AMENORRHOEA. An individual’s body image may be distorted so that the su?erer cannot judge real weight and wants to diet even when already very thin.

Anorexia nervosa usually begins in adolescence, a?ecting about 1–2 per cent of teenagers and college students at any time. It is 20 times more common among women than men. Up to 10 per cent of su?erers’ sisters also have the syndrome. Anorexia may be linked with episodes of bulimia (see below).

The symptoms result from secretive self-starvation, usually with excessive exercise, self-induced vomiting, and misuse of laxatives. An anorexic (or anorectic) person may wear layers of baggy clothes to keep warm and to hide the ?gure. Starvation can cause serious problems such as ANAEMIA, low blood pressure, slow heart rate, swollen ankles, and osteoporosis. Sudden death from heart ARRHYTHMIA may occur, particularly if the su?erer misuses DIURETICS to lose weight and also depletes the body’s level of potassium.

There is probably no single cause of anorexia nervosa. Social pressure to be thin seems to be an important factor and has increased over the past 20–30 years, along with the incidence of the syndrome. Psychological theories include fear of adulthood and fear of losing parents’ attention.

Treatment should start with the general practitioner who should ?rst rule out other illnesses causing similar signs and symptoms. These include DEPRESSION and disorders of the bowel, PITUITARY GLAND, THYROID GLAND, and OVARIES.

If the diagnosis is clearly anorexia nervosa, the general practitioner may refer the su?erer to a psychiatrist or psychologist. Moderately ill su?erers can be treated by COGNITIVE BEHAVIOUR THERAPY. A simple form of this is to agree targets for daily calorie intake and for acceptable body weight. The su?erer and the therapist (the general practitioner or a member of the psychiatric team) then monitor progress towards both targets by keeping a diary of food intake and measuring weight regularly. Counselling or more intensely personal PSYCHOTHERAPY may help too. Severe life-threatening complications will need urgent medical treatment in hospital, including rehydration and feeding using a nasogastric tube or an intravenous drip.

About half of anorectic su?erers recover fully within four years, a quarter improve, and a quarter remain severely underweight with (in the case of women) menstrual abnormalities. Recovery after ten years is rare and about 3 per cent die within that period, half of them by suicide.

Bulimia nervosa is a syndrome characterised by binge eating, self-induced vomiting and laxative misuse, and fear of fatness. There is some overlap between anorexia nervosa and bulimia but, unlike the former, bulimia may start at any age from adolescence to 40 and is probably more directly linked with ordinary dieting. Bulimic su?erers say that, although they feel depressed and guilty after binges, the ‘buzz’ and relief after vomiting and purging are addictive. They often respond well to cognitive behaviour therapy.

Bulimia nervosa does not necessarily cause weight loss because the binges – for example of a loaf of bread, a packet of cereal, and several cans of cold baked beans at one sitting – are cancelled out by purging, by self-induced vomiting and by brief episodes of starvation. The full syndrome has been found in about 1 per cent of women but mild forms may be much more common. In one survey of female college students, 13 per cent admitted to having had bulimic symptoms.

Bulimia nervosa rarely leads to serious physical illness or death. However, repeated vomiting can cause oesophageal burns, salivary gland infections, small tears in the stomach, and occasionally dehydration and chemical imbalances in the blood. Inducing vomiting using ?ngers may produce two tell-tale signs – bite marks on the knuckles and rotten, pitted teeth.

Those su?ering from this condition may obtain advice from the Eating Disorders Association.... Medical Dictionary

ENT DISORDERS

Medical Dictionary

See OTORHINOLARYNGOLOGY.... Medical Dictionary

EYE, DISORDERS OF

Medical Dictionary

Arcus senilis The white ring or crescent which tends to form at the edge of the cornea with age. It is uncommon in the young, when it may be associated with high levels of blood lipids (see LIPID).

Astigmatism (See ASTIGMATISM.)

Blepharitis A chronic in?ammation of the lid margins. SEBORRHOEA and staphylococcal infection are likely contributors. The eyes are typically intermittently red, sore and gritty over months or years. Treatment is di?cult and may fail. Measures to reduce debris on the lid margins, intermittent courses of topical antibiotics, steroids or systemic antibiotics may help the su?erer.

Blepharospasm Involuntary closure of the eye. This may accompany irritation but may also occur without an apparent cause. It may be severe enough to interfere with vision. Treatment involves removing the source of irritation, if present. Severe and persistent cases may respond to injection of Botulinum toxin into the orbicularis muscle.

Cataract A term used to describe any opacity in the lens of the eye, from the smallest spot to total opaqueness. The prevalence of cataracts is age-related: 65 per cent of individuals in their sixth decade have some degree of lens opacity, while all those over 80 are a?ected. Cataracts are the most important cause of blindness worldwide. Symptoms will depend on whether one or both eyes are a?ected, as well as the position and density of the cataract(s). If only one eye is developing a cataract, it may be some time before the person notices it, though reading may be a?ected. Some people with cataracts become shortsighted, which in older people may paradoxically ‘improve’ their ability to read. Bright light may worsen vision in those with cataracts.

The extent of visual impairment depends on the nature of the cataracts, and the ?rst symptoms noticed by patients include di?culty in recognising faces and in reading, while problems watching television or driving, especially at night, are pointers to the condition. Cataracts are common but are not the only cause of deteriorating vision. Patients with cataracts should be able to point to the position of a light and their pupillary reactions should be normal. If a bright light is shone on the eye, the lens may appear brown or, in advanced cataracts, white (see diagram).

While increasing age is the commonest cause of cataract in the UK, patients with DIABETES MELLITUS, UVEITIS and a history of injury to the eye can also develop the disorder. Prolonged STEROID treatment can result in cataracts. Children may develop cataracts, and in them the condition is much more serious as vision may be irreversibly impaired because development of the brain’s ability to interpret visual signals is hindered. This may happen even if the cataracts are removed, so early referral for treatment is essential. One of the physical signs which doctors look for when they suspect cataract in adults as well as in children is the ‘red re?ex’. This is observable when an ophthalmoscopic examination of the eye is made (see OPHTHALMOSCOPE). Identi?cation of this red re?ex (a re?ection of light from the red surface of the retina –see EYE) is a key diagnostic sign in children, especially young ones.

There is no e?ective medical treatment for established cataracts. Surgery is necessary and the decision when to operate depends mainly on how the cataract(s) a?ect(s) the patient’s vision. Nowadays, surgery can be done at any time with limited risk. Most patients with a vision of 6/18 – 6/10 is the minimum standard for driving – or worse in both eyes should

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bene?t from surgery, though elderly people may tolerate visual acuity of 6/18 or worse, so surgery must be tailored to the individual’s needs. Younger people with a cataract will have more demanding visual requirements and so may opt for an ‘earlier’ operation. Most cataract surgery in Britain is now done under local anaesthetic and uses the ‘phaco-emulsi?cation’ method. A small hole is made in the anterior capsule of the lens after which the hard lens nucleus is liqui?ed ultrasonically. A replacement lens is inserted into the empty lens bag (see diagram). Patients usually return to their normal activities within a few days of the operation. A recent development under test in the USA for children requiring cataract operations is an intra-ocular ?exible implant whose magnifying power can be altered as a child develops, thus precluding the need for a series of corrective operations as happens now.

Chalazion A ?rm lump in the eyelid relating to a blocked meibomian gland, felt deep within the lid. Treatment is not always necessary; a proportion spontaneously resolve. There can be associated infection when the lid becomes red and painful requiring antibiotic treatment. If troublesome, the chalazion can be incised under local anaesthetic.

Conjunctivitis In?ammation of the conjunctiva (see EYE) which may a?ect one or both eyes. Typically the eye is red, itchy, sticky and gritty but is not usually painful. Redness is not always present. Conjunctivitis can occasionally be painful, particularly if there is an associated keratitis (see below) – for example, adenovirus infection, herpetic infection.

The cause can be infective (bacteria, viruses or CHLAMYDIA), chemical (e.g. acids, alkalis) or allergic (e.g. in hay fever). Conjunctivitis may also be caused by contact lenses, and preservatives or even the drugs in eye drops may cause conjunctival in?ammation. Conjunctivitis may addtionally occur in association with other illnesses – for example, upper-respiratory-tract infection, Stevens-Johnson syndrome (see ERYTHEMA – erythema multiforme) or REITER’S SYNDROME. The treatment depends on the cause. In many patients acute conjunctivitis is self-limiting.

Dacryocystitis In?ammation of the lacrimal sac. This may present acutely as a red, painful swelling between the nose and the lower lid. An abscess may form which points through the skin and which may need to be drained by incision. Systemic antibiotics may be necessary. Chronic dacryocystitis may occur with recurrent discharge from the openings of the tear ducts and recurrent swelling of the lacrimal sac. Obstruction of the tear duct is accompanied by watering of the eye. If the symptoms are troublesome, the patient’s tear passageways need to be surgically reconstructed.

Ectropion The lid margin is everted – usually the lower lid. Ectropion is most commonly associated with ageing, when the tissues of the lid become lax. It can also be caused by shortening of the skin of the lids such as happens with scarring or mechanical factors – for example, a tumour pulling the skin of the lower lid downwards. Ectropion tends to cause watering and an unsightly appearance. The treatment is surgical.

Entropion The lid margin is inverted – usually the lower lid. Entropion is most commonly associated with ageing, when the tissues of the lid become lax. It can also be caused by shortening of the inner surfaces of the lids due to scarring – for example, TRACHOMA or chemical burns. The inwardly directed lashes cause irritation and can abrade the cornea. The treatment is surgical.

Episcleritis In?ammation of the EPISCLERA. There is usually no apparent cause. The in?ammation may be di?use or localised and may a?ect one or both eyes. It sometimes recurs. The a?ected area is usually red and moderately painful. Episcleritis is generally not thought to be as painful as scleritis and does not lead to the same complications. Treatment is generally directed at improving the patient’s symptoms. The in?ammation may respond to NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) or topical CORTICOSTEROIDS.

Errors of refraction (Ametropia.) These will occur when the focusing power of the lens and cornea does not match the length of the eye, so that rays of light parallel to the visual axis are not focused at the fovea centralis (see EYE). There are three types of refractive error: HYPERMETROPIA or long-sightedness. The refractive power of the eye is too weak, or the eye is too short so that rays of light are brought to a focus at a point behind the retina. Longsighted people can see well in the distance but generally require glasses with convex lenses for reading. Uncorrected long sight can lead to headaches and intermittent blurring of vision following prolonged close work (i.e. eye strain). As a result of ageing, the eye becomes gradually long-sighted, resulting in many people needing reading glasses in later life: this normal process is known as presbyopia. A particular form of long-sightedness occurs after cataract extraction (see above). MYOPIA(Short sight or near sight.) Rays of light are brought to a focus in front of the retina because the refractive power of the eye is too great or the eye is too short. Short-sighted people can see close to but need spectacles with concave lenses in order to see in the distance. ASTIGMATISMThe refractive power of the eye is not the same in each meridian. Some rays of light may be focused in front of the retina while others are focused on or behind the retina. Astigmatism can accompany hypermetropia or myopia. It may be corrected by cylindrical lenses: these consist of a slice from the side of a cylinder (i.e. curved in one meridian and ?at in the meridian at right-angles to it).

Keratitis In?ammation of the cornea in response to a variety of insults – viral, bacterial, chemical, radiation, or mechanical trauma. Keratitis may be super?cial or involve the deeper layers, the latter being generally more serious. The eye is usually red, painful and photophobic. Treatment is directed at the cause.

Nystagmus Involuntary rhythmic oscillation of one or both eyes. There are several causes including nervous disorders, vestibular disorders, eye disorders and certain drugs including alcohol.

Ophthalmia In?ammation of the eye, especially the conjunctiva (see conjunctivitis, above). Ophthalmia neonatorum is a type of conjunctivitis that occurs in newborn babies. They catch the disease when passing through an infected birth canal during their mother’s labour (see PREGNANCY AND LABOUR). CHLAMYDIA and GONORRHOEA are the two most common infections. Treatment is e?ective with antibiotics: untreated, the infection may cause permanent eye damage.

Pinguecula A benign degenerative change in the connective tissue at the nasal or temporal limbus (see EYE). This is visible as a small, ?attened, yellow-white lump adjacent to the cornea.

Pterygium Overgrowth of the conjunctival tissues at the limbus on to the cornea (see EYE). This usually occurs on the nasal side and is associated with exposure to sunlight. The pterygium is surgically removed for cosmetic reasons or if it is thought to be advancing towards the visual axis.

Ptosis Drooping of the upper lid. May occur because of a defect in the muscles which raise the lid (levator complex), sometimes the result of ageing or trauma. Other causes include HORNER’S SYNDROME, third cranial nerve PALSY, MYASTHENIA GRAVIS, and DYSTROPHIA MYOTONICA. The cause needs to be determined and treated if possible. The treatment for a severely drooping lid is surgical, but other measures can be used to prop up the lid with varying success.

Retina, disorders of The retina can be damaged by disease that a?ects the retina alone, or by diseases a?ecting the whole body.

Retinopathy is a term used to denote an abnormality of the retina without specifying a cause. Some retinal disorders are discussed below. DIABETIC RETINOPATHY Retinal disease occurring in patients with DIABETES MELLITUS. It is the commonest cause of blind registration in Great Britain of people between the ages of 20 and 65. Diabetic retinopathy can be divided into several types. The two main causes of blindness are those that follow: ?rst, development of new blood vessels from the retina, with resultant complications and, second, those following ‘water logging’ (oedema) of the macula. Treatment is by maintaining rigid control of blood-sugar levels combined with laser treatment for certain forms of the disease – in particular to get rid of new blood vessels. HYPERTENSIVE RETINOPATHY Retinal disease secondary to the development of high blood pressure. Treatment involves control of the blood pressure (see HYPERTENSION). SICKLE CELL RETINOPATHY People with sickle cell disease (see under ANAEYIA) can develop a number of retinal problems including new blood vessels from the retina. RETINOPATHY OF PREMATURITY (ROP) Previously called retrolental ?broplasia (RLF), this is a disorder a?ecting low-birth-weight premature babies exposed to oxygen. Essentially, new blood vessels develop which cause extensive traction on the retina with resultant retinal detachment and poor vision. RETINAL ARTERY OCCLUSION; RETINAL VEIN OCCLUSION These result in damage to those areas of retina supplied by the a?ected blood vessel: the blood vessels become blocked. If the peripheral retina is damaged the patient may be completely symptom-free, although areas of blindness may be detected on examination of ?eld of vision. If the macula is involved, visual loss may be sudden, profound and permanent. There is no e?ective treatment once visual loss has occurred. SENILE MACULAR DEGENERATION (‘Senile’ indicates age of onset and has no bearing on mental state.) This is the leading cause of blindness in the elderly in the western world. The average age of onset is 65 years. Patients initially notice a disturbance of their vision which gradually progresses over months or years. They lose the ability to recognise ?ne detail; for example, they cannot read ?ne print, sew, or recognise people’s faces. They always retain the ability to recognise large objects such as doors and chairs, and are therefore able to get around and about reasonably well. There is no e?ective treatment in the majority of cases. RETINITIS PIGMENTOSAA group of rare, inherited diseases characterised by the development of night blindness and tunnel vision. Symptoms start in childhood and are progressive. Many patients retain good visual acuity, although their peripheral vision is limited. One of the characteristic ?ndings on examination is collections of pigment in the retina which have a characteristic shape and are therefore known as ‘bone spicules’. There is no e?ective treatment. RETINAL DETACHMENTusually occurs due to the development of a hole in the retina. Holes can occur as a result of degeneration of the retina, traction on the retina by the vitreous, or injury. Fluid from the vitreous passes through the hole causing a split within the retina; the inner part of the retina becomes detached from the outer part, the latter remaining in contact with the choroid. Detached retina loses its ability to detect light, with consequent impairment of vision. Retinal detachments are more common in the short-sighted, in the elderly or following cataract extraction. Symptoms include spots before the eyes (?oaters), ?ashing lights and a shadow over the eye with progressive loss of vision. Treatment by laser is very e?ective if caught early, at the stage when a hole has developed in the retina but before the retina has become detached. The edges of the hole can be ‘spot welded’ to the underlying choroid. Once a detachment has occurred, laser therapy cannot be used; the retina has to be repositioned. This is usually done by indenting the wall of the eye from the outside to meet the retina, then making the retina stick to the wall of the eye by inducing in?ammation in the wall (by freezing it). The outcome of surgery depends largely on the extent of the detachment and its duration. Complicated forms of detachment can occur due to diabetic eye disease, injury or tumour. Each requires a specialised form of treatment.

Scleritis In?ammation of the sclera (see EYE). This can be localised or di?use, can a?ect the anterior or the posterior sclera, and can a?ect one or both eyes. The a?ected eye is usually red and painful. Scleritis can lead to thinning and even perforation of the sclera, sometimes with little sign of in?ammation. Posterior scleritis in particular may cause impaired vision and require emergency treatment. There is often no apparent cause, but there are some associated conditions – for example, RHEUMATOID ARTHRITIS, GOUT, and an autoimmune disease a?ecting the nasal passages and lungs called Wegener’s granulomatosis. Treatment depends on severity but may involve NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), topical CORTICOSTEROIDS or systemic immunosuppressive drugs.

Stye Infection of a lash follicle. This presents as a painful small red lump at the lid margin. It often resolves spontaneously but may require antibiotic treatment if it persists or recurs.

Sub-conjunctival haemorrhage Haemorrhage between the conjunctiva and the underlying episclera. It is painless. There is usually no apparent cause and it resolves spontaneously.

Trichiasis Inward misdirection of the lashes. Trichiasis occurs due to in?ammation of or trauma to the lid margin. Treatment involves removal of the patient’s lashes. Regrowth may be prevented by electrolysis, by CRYOTHERAPY to the lid margin, or by surgery.

For the subject of arti?cial eyes, see under PROSTHESIS; also GLAUCOMA, SQUINT and UVEITIS.... Medical Dictionary

GENDER IDENTITY DISORDERS

Medical Dictionary

Gender identity is the inner sense of masculinity or femininity, and gender role is an individual’s public expression of being male, female, or a ‘mix’ (androgynous). Most people have no di?culty because their gender identity and role are congruous. A person with a gender identity disorder, however, has a con?ict between anatomical sex and gender identity.

Gender is determined by a combination of genetic and environmental factors, in which the in?uence of family upbringing is an important factor. When physical sexual characteristics are ambiguous, the child’s gender identity can usually be established if the child is reared as being clearly male or female. Should, however, the child be confused about its sexual identity, the uncertainty may continue into adult life. Transsexuals generally experience con?icts of identity in childhood, and such problems usually occur by the age of two years. In this type of identity disorder, which occurs in one in 30,000 male births and one in 100,000 female births, the person believes that he or she is the victim of a biological accident, trapped in a body different from what is felt to be his or her true sex.

Treatment is di?cult: psychotherapy and hormone treatment may help, but some a?ected individuals want surgery to change their body’s sexual organs to match their innately felt sexual gender. The decision to seek a physical sex change raises major social problems for individuals, and ethical problems for their doctors. Surgery, which is not always successful in the long term, requires careful assessment, discussion and planning. It is important to preclude mental illness; results in homosexual men who have undergone surgery are not usually satisfactory. Advice and information may be obtained from Gender Identity Consultancy Services.... Medical Dictionary

GENETIC DISORDERS

Medical Dictionary

These are caused when there are mutations or other abnormalities which disrupt the code of a gene or set of GENES. These are divided into autosomal (one of the 44 CHROMOSOMES which are not sex-linked), dominant, autosomal recessive, sex-linked and polygenic disorders.

Dominant genes A dominant characteristic is an e?ect which is produced whenever a gene or gene defect is present. If a disease is due to a dominant gene, those a?ected are heterozygous – that is, they only carry a fault in the gene on one of the pair of chromosomes concerned. A?ected people married to normal individuals transmit the gene directly to one-half of the children, although this is a random event just like tossing a coin. HUNTINGTON’S CHOREA is due to the inheritance of a dominant gene, as is neuro?bromatosis (see VON RECKLINGHAUSEN’S DISEASE) and familial adenomatous POLYPOSIS of the COLON. ACHONDROPLASIA is an example of a disorder in which there is a high frequency of a new dominant mutation, for the majority of a?ected people have normal parents and siblings. However, the chances of the children of a parent with the condition being a?ected are one in two, as with any other dominant characteristic. Other diseases inherited as dominant characteristics include spherocytosis, haemorrhagic telangiectasia and adult polycystic kidney disease.

Recessive genes If a disease is due to a recessive gene, those a?ected must have the faulty gene on both copies of the chromosome pair (i.e. be homozygous). The possession of a single recessive gene does not result in overt disease, and the bearer usually carries this potentially unfavourable gene without knowing it. If that person marries another carrier of the same recessive gene, there is a one-in-four chance that their children will receive the gene in a double dose, and so have the disease. If an individual su?erer from a recessive disease marries an apparently normal person who is a heterozygous carrier of the same gene, one-half of the children will be a?ected and the other half will be carriers of the disease. The commonest of such recessive conditions in Britain is CYSTIC FIBROSIS, which a?ects about one child in 2,000. Approximately 5 per cent of the population carry a faulty copy of the gene. Most of the inborn errors of metabolism, such as PHENYLKETONURIA, GALACTOSAEMIA and congenital adrenal hyperplasia (see ADRENOGENITAL SYNDROME), are due to recessive genes.

There are characteristics which may be incompletely recessive – that is, neither completely dominant nor completely recessive – and the heterozygotus person, who bears the gene in a single dose, may have a slight defect whilst the homozygotus, with a double dose of the gene, has a severe illness. The sickle-cell trait is a result of the sickle-cell gene in single dose, and sickle-cell ANAEMIA is the consequence of a double dose.

Sex-linked genes If a condition is sex-linked, a?ected males are homozygous for the mutated gene as they carry it on their single X chromosome. The X chromosome carries many genes, while the Y chromosome bears few genes, if any, other than those determining masculinity. The genes on the X chromosome of the male are thus not matched by corresponding genes on the Y chromosome, so that there is no chance of the Y chromosome neutralising any recessive trait on the X chromosome. A recessive gene can therefore produce disease, since it will not be suppressed by the normal gene of the homologous chromosome. The same recessive gene on the X chromosome of the female will be suppressed by the normal gene on the other X chromosome. Such sex-linked conditions include HAEMOPHILIA, CHRISTMAS DISEASE, DUCHENNE MUSCULAR

DYSTROPHY (see also MUSCLES, DISORDERS OF – Myopathy) and nephrogenic DIABETES INSIPIDUS.

If the mother of an a?ected child has another male relative a?ected, she is a heterozygote carrier; half her sons will have the disease and half her daughters will be carriers. The sister of a haemophiliac thus has a 50 per cent chance of being a carrier. An a?ected male cannot transmit the gene to his son because the X chromosome of the son must come from the mother; all his daughters, however, will be carriers as the X chromosome for the father must be transmitted to all his daughters. Hence sex-linked recessive characteristics cannot be passed from father to son. Sporadic cases may be the result of a new mutation, in which case the mother is not the carrier and is not likely to have further a?ected children. It is probable that one-third of haemophiliacs arise as a result of fresh mutations, and these patients will be the ?rst in the families to be a?ected. Sometimes the carrier of a sex-linked recessive gene can be identi?ed. The sex-linked variety of retinitis pigmentosa (see EYE, DISORDERS OF) can often be detected by ophthalmoscopic examination.

A few rare disorders are due to dominant genes carried on the X chromosome. An example of such a condition is familial hypophosphataemia with vitamin-D-resistant RICKETS.

Polygenic inheritance In many inherited conditions, the disease is due to the combined action of several genes; the genetic element is then called multi-factorial or polygenic. In this situation there would be an increased incidence of the disease in the families concerned, but it will not follow the Mendelian (see MENDELISM; GENETIC CODE) ratio. The greater the number of independent genes involved in determining a certain disease, the more complicated will be the pattern of inheritance. Furthermore, many inherited disorders are the result of a combination of genetic and environmental in?uences. DIABETES MELLITUS is the most familiar of such multi-factorial inheritance. The predisposition to develop diabetes is an inherited characteristic, although the gene is not always able to express itself: this is called incomplete penetrance. Whether or not the individual with a genetic predisposition towards the disease actually develops diabetes will also depend on environmental factors. Diabetes is more common in the relatives of diabetic patients, and even more so amongst identical twins. Non-genetic factors which are important in precipitating overt disease are obesity, excessive intake of carbohydrate foods, and pregnancy.

SCHIZOPHRENIA is another example of the combined e?ects of genetic and environmental in?uences in precipitating disease. The risk of schizophrenia in a child, one of whose parents has the disease, is one in ten, but this ?gure is modi?ed by the early environment of the child.... Medical Dictionary

LARYNX, DISORDERS OF

Medical Dictionary

Obstruction of the larynx is potentially dangerous in adults but can sometimes be life-threatening in infants and children. Stridor – noisy, di?cult breathing – is a symptom of obstruction. There are several causes, including congenital abnormalities of the larynx. Others are in?ammatory conditions such as acute laryngitis (see below), acute EPIGLOTTITIS and laryngo-tracheo-bronchitis (croup – see below); neurological abnormalities; trauma; and inhalation of foreign bodies.

Laryngitis In?ammation of the mucous membrane of the larynx and vocal chords may be acute or chronic. The cause is usually an infection, most commonly viral, although it may be the result of secondary bacterial infection, voice abuse or irritation by gases or chemicals. ACUTE LARYNGITIS may accompany any form of upper-respiratory-tract infection. The main symptom is hoarseness and often pain in the throat. The voice becomes husky or it may be lost. Cough, breathing di?culties and sometimes stridor may occur. Acute airway obstruction is unusual following laryngitis but may occasionally occur in infants (see laryngotracheo-bronchitis, below).

Treatment Vapour inhalations may be soothing and reduce swelling. Usually all that is needed is rest and analgesics such as paracetamol. Rarely, airway intervention – either ENDOTRACHEAL INTUBATION or TRACHEOSTOMY – may be necessary if severe airway obstruction develops (see APPENDIX 1: BASIC FIRST AID). A?ected patients should rest their voice and avoid smoking.

Chronic laryngitis can result from repeated attacks of acute laryngitis; excessive use of the voice – loud and prolonged, singing or shouting; tumours, which may be benign or malignant; or secondary to diseases such as TUBERCULOSIS and SYPHILIS.

Benign tumours or small nodules, such as singer’s nodules, may be surgically removed by direct laryngoscopy under general anaesthetic; while cancer of the larynx may be treated either by RADIOTHERAPY or by SURGERY, depending on the extent of the disease. Hoarseness may be the only symptom of vocal-chord disturbance or of laryngeal cancer: any case which has lasted for six weeks should be referred for a specialist opinion.

Laryngectomy clubs are being established

A laryngoscopic view of the interior of the larynx.

throughout the country to support patients following laryngectomy. Speech therapists provide speech rehabilitation.... Medical Dictionary

METABOLIC DISORDERS

Medical Dictionary

A collection of disorders in which some part of the body’s internal chemistry (see METABOLISM; CATABOLISM) is disrupted. Some of these disorders arise from inherited de?ciencies in which a speci?c ENZYME is absent or abnormal, or does not function properly. Other metabolic disorders occur because of malfunctions in the endocrine system (see ENDOCRINE GLANDS). There may be over- or underproduction of a hormone involved in the control of metabolic activities: a prime example is DIABETES MELLITUS – a disorder of sugar metabolism; others include CUSHING’S SYNDROME; hypothyroidism and hyperthyroidism (see THYROID GLAND, DISEASES OF); and insulinoma (an insulin-producing tumour of the pancreas). The bones can be a?ected by metabolic disorders such as osteoporosis, osteomalacia (rickets) and Paget’s disease (see under BONE, DISORDERS OF). PORPHYRIAS, HYPERLIPIDAEMIA, HYPERCALCAEMIA and gout are other examples of disordered metabolism.

There are also more than 200 identi?ed disorders described as inborn errors of metabolism. Some cause few problems; others are serious threats to an individual’s life. Individual disorders are, fortunately, rare – probably one child in 10,000 or 100,000; overall these inborn errors a?ect around one child in 1,000. Examples include GALACTOSAEMIA, PHENYLKETONURIA, porphyrias, TAY SACHS DISEASE and varieties of mucopolysaccharidosis, HOMOCYSTINURIA and hereditary fructose (a type of sugar) intolerance.... Medical Dictionary

MULTIPLE PERSONALITY DISORDER

Medical Dictionary

The individual with this psychiatric disorder has two or more di?erent personalities, often contrasting. The dominant personality at the time determines the behaviour and attitude of the individual, who customarily seems not to know about the other personality – or personalities. The switch from one personality to another is abrupt and the mental condition of the di?ering personalities is usually normal. It is possible that child abuse is a factor in the disorder, which is treated by psychotherapy. The classic multiple personality was the ?ctional form of Dr Jekyll and Mr Hyde.... Medical Dictionary

MUSCLES, DISORDERS OF

Medical Dictionary

Compression syndrome The tense, painful state of muscles induced by excessive accumulation of INTERSTITIAL ?uid in them, following unusual exercise. This condition is more liable to occur in the muscles at the front of the shin, because they lie within a tight fascial membrane: here the syndrome is known as the anterior tibial syndrome (‘shin splints’). Prevention consists of always keeping ?t and in training for the amount of exercise to be undertaken. Equally important is what is known in sporting circles as ‘warming down’: i.e., at the end of training or a game, exercise should be gradually tailed o?. Treatment consists of elevation of the a?ected limb, compression of it by compression bandages, with ample exercise of the limb within the bandage, and massage. In more severe cases DIURETICS may be given. Occasionally surgical decompression may be necessary.

Cramp Painful spasm of a muscle usually caused by excessive and prolonged contraction of the muscle ?bres. Cramps are common, especially among sportsmen and women, normally lasting a short time. The condition usually occurs during or immediately following exercise as a result of a build-up of LACTIC ACID and other chemical by-products in the muscles

– caused by the muscular e?orts. Cramps may occur more frequently, especially at night, in people with poor circulation, when the blood is unable to remove the lactic acid from the muscles quickly enough.

Repetitive movements such as writing (writer’s cramp) or operating a keyboard can cause cramp. Resting muscles may su?er cramp if a person sits or lies in an awkward position which limits local blood supply to them. Profuse sweating as a result of fever or hot weather can also cause cramp in resting muscle, because the victim has lost sodium salts in the sweat; this disturbs the biochemical balance in muscle tissue.

Treatment is to massage and stretch the a?ected muscle – for example, cramp in the calf muscle may be relieved by pulling the toes on the a?ected leg towards the knee. Persistent night cramps sometimes respond to treatment with a drug containing CALCIUM or QUININE. If cramp persists for an hour or more, the person should seek medical advice, as there may be a serious cause such as a blood clot impeding the blood supply to the area a?ected.

Dystrophy See myopathy below.

In?ammation (myositis) of various types may occur. As the result of injury, an ABSCESS may develop, although wounds a?ecting muscle generally heal well. A growth due to SYPHILIS, known as a gumma, sometimes forms a hard, almost painless swelling in a muscle. Rheumatism is a vague term traditionally used to de?ne intermittent and often migratory discomfort, sti?ness or pain in muscles and joints with no obvious cause. The most common form of myositis is the result of immunological damage as a result of autoimmune disease. Because it a?ects many muscles it is called POLYMYOSITIS.

Myasthenia (see MYASTHENIA GRAVIS) is muscle weakness due to a defect of neuromuscular conduction.

Myopathy is a term applied to an acquired or developmental defect in certain muscles. It is not a neurological disease, and should be distinguished from neuropathic conditions (see NEUROPATHY) such as MOTOR NEURONE DISEASE (MND), which tend to a?ect the distal limb muscles. The main subdivisions are genetically determined, congenital, metabolic, drug-induced, and myopathy (often in?ammatory) secondary to a distant carcinoma. Progressive muscular dystrophy is characterised by symmetrical wasting and weakness, the muscle ?bres being largely replaced by fatty and ?brous tissue, with no sensory loss. Inheritance may take several forms, thus a?ecting the sex and age of victims.

The commonest type is DUCHENNE MUSCULAR DYSTROPHY, which is inherited as a sex-linked disorder. It nearly always occurs in boys.

Symptoms There are three chief types of myopathy. The commonest, known as pseudohypertrophic muscular dystrophy, a?ects particularly the upper part of the lower limbs of children. The muscles of the buttocks, thighs and calves seem excessively well developed, but nevertheless the child is clumsy, weak on his legs, and has di?culty in picking himself up when he falls. In another form of the disease, which begins a little later, as a rule at about the age of 14, the muscles of the upper arm are ?rst a?ected, and those of the spine and lower limbs become weak later on. In a third type, which begins at about this age, the muscles of the face, along with certain of the shoulder and upper arm muscles, show the ?rst signs of wasting. All the forms have this in common: that the a?ected muscles grow weaker until their power to contract is quite lost. In the ?rst form, the patients seldom reach the age of 20, falling victims to some disease which, to ordinary people, would not be serious. In the other forms the wasting, after progressing to a certain extent, often remains stationary for the rest of life. Myopathy may also be acquired when it is the result of disease such as thyrotoxicosis (see under THYROID GLAND, DISEASES OF), osteomalacia (see under BONE, DISORDERS OF) and CUSHING’S DISEASE, and the myopathy resolves when the primary disease is treated.

Treatment Some myopathies may be the result of in?ammation or arise from an endocrine or metabolic abnormality. Treatment of these is the treatment of the cause, with supportive physiotherapy and any necessary physical aids while the patient is recovering. Treatment for the hereditary myopathies is supportive since, at present, there is no cure – although developments in gene research raise the possibility of future treatment. Physiotherapy, physical aids, counselling and support groups may all be helpful in caring for these patients.

The education and management of these children raise many di?culties. Much help in dealing with these problems can be obtained from Muscular Dystrophy Campaign.

Myositis ossi?cans, or deposition of bone in muscles, may be congenital or acquired. The congenital form, which is rare, ?rst manifests itself as painful swellings in the muscles. These gradually harden and extend until the child is encased in a rigid sheet. There is no e?ective treatment and the outcome is fatal.

The acquired form is a result of a direct blow on muscle, most commonly on the front of the thigh. The condition should be suspected whenever there is severe pain and swelling following a direct blow over muscle. The diagnosis is con?rmed by hardening of the swelling. Treatment consists of short-wave DIATHERMY with gentle active movements. Recovery is usually complete.

Pain, quite apart from any in?ammation or injury, may be experienced on exertion. This type of pain, known as MYALGIA, tends to occur in un?t individuals and is relieved by rest and physiotherapy.

Parasites sometimes lodge in the muscles, the most common being Trichinella spiralis, producing the disease known as TRICHINOSIS (trichiniasis).

Rupture of a muscle may occur, without any external wound, as the result of a spasmodic e?ort. It may tear the muscle right across – as sometimes happens to the feeble plantaris muscle in running and leaping – or part of the muscle may be driven through its ?brous envelope, forming a HERNIA of the muscle. The severe pain experienced in many cases of LUMBAGO is due to tearing of one of the muscles in the back. These conditions are usually relieved by rest and massage. Partial muscle tears, such as occur in sport, require more energetic treatment: in the early stages this consists of the application of an ice or cold-water pack, ?rm compression, elevation of the a?ected limb, rest for a day or so and then gradual mobilisation (see SPORTS MEDICINE).

Tumours occur occasionally, the most common being ?broid, fatty, and sarcomatous growths.

Wasting of muscles sometimes occurs as a symptom of disease in other organs: for example, damage to the nervous system, as in poliomyelitis or in the disease known as progressive muscular atrophy. (See PARALYSIS.)... Medical Dictionary

NERVOUS SYSTEM, DISORDERS OF

Medical Dictionary

The following conditions are discussed under their individual headings: APHASIA; BRAIN, DISEASES OF; CATALEPSY; CHOREA; CRAMP; EPILEPSY; HYSTERIA; LEARNING DISABILITY; MEMORY; MENTAL ILLNESS; MULTIPLE SCLEROSIS (MS); NERVES, INJURIES TO; NEURALGIA; NEURITIS; PARALYSIS; PSYCHOSOMATIC DISEASES; SPINE AND SPINAL CORD, DISEASES AND INJURIES OF; STROKE; TABES.... Medical Dictionary

NOSE, DISORDERS OF

Medical Dictionary

Certain skin diseases – particularly CHILBLAIN, ACNE, LUPUS and ERYSIPELAS – tend to a?ect the NOSE, and may be very annoying. Redness of the skin may be caused by poor circulation in cold weather.

Acute in?ammation is generally the result of a viral infection (see COLD, COMMON) a?ecting the mucous membrane and paranasal sinuses (see SINUSITIS); less commonly it results from the inhalation of irritant gases. Boils may develop just inside the entrance to the nose, causing pain; these are potentially troublesome as infection can spread to the sinuses. HAY FEVER is one distressing form of acute rhinitis.

Malformations are of various kinds. Racial and familial variations in the external nose occur and may be a reason for RHINOPLASTY. Di?erences in the size and shape of the nose occur, often forming the starting point for chronic in?ammation of the nose, perennial rhinitis (all the year round), hay fever, or ASTHMA. More commonly, obstruction results from nasal polyps or adenoids, leading to inhalation through the mouth. Adenoids are an overgrowth of glandular tissue at the back of the throat, into which the nose opens. Polyps are growths of soft jelly-like character: they arise from chronic in?ammation associated with allergic rhinitis, chronic sinusitis, asthma, and aspirin abuse. Large polyps can cause erosion of the nasal bones and should be surgically removed.

Bleeding (see HAEMORRHAGE).

Foreign bodies At ?rst these may not cause any symptoms, but in time they can cause obstruction of the a?ected nostril with a foul-smelling bloody discharge. The problem is common with small children who tend to push small objects into their noses. Foreign bodies require removal, sometimes in hospital. Anyone attempting to remove a foreign body should take care not to push it further into the nose.

Loss of sense of smell, or anosmia, may be temporary or permanent. Temporary anosmia is caused by conditions of the nose which are reversible, whereas permanent

anosmia is caused by conditions which destroy the OLFACTORY NERVES. Temporary conditions are those such as the common cold, or other in?ammatory conditions of the nasal mucosa or the presence of nasal polyps (see above). Permanent anosmia may follow in?uenzal NEURITIS or it may also follow injuries to the brain and fractures of the skull involving the olfactory nerves.

Injury to nose The commonest injury is a fracture of the nasal bones or displacement of the cartilage that forms the bridge of the nose. The nasal SEPTUM may also be displaced sideways by a lateral blow. Sporting activities, especially boxing and rugby football, are commonly a cause of nasal injury. If a fracture is suspected, or if there is substantial tissue swelling, an X-ray examination is necessary. Resetting a damaged bone should be done either immediately, before swelling makes surgery di?cult, or ten days or so later when the swelling has subsided. Results are usually good, ensuring a clear airway as well as a restored pro?le. It is not unusual for the cheek-bone to sustain a depressed fracture at the same time as the nose is broken. Careful assessment and prompt surgery are called for. (For more information on fractures, see under BONE, DISORDERS OF).

Rhinitis In?ammation of the MUCOUS MEMBRANE lining the nose. Symptoms include nasal discharge and obstruction, sneezing and sometimes pain in the sinuses. There are several types of rhinitis:

•Allergic – due to allergy to dust, pollen or other airborne particles. Also called hay fever, allergic rhinitis causes a runny nose, sneezing and local congestion. It a?ects up to 10 per cent of the population and is more common in people su?ering from other allergic disorders such as asthma or eczema (see DERMATITIS). Skin tests help to identify the causative ALLERGEN which the su?erer can then try to avoid, although in the case of pollen this is di?cult. Decongestant drugs, ANTIHISTAMINE DRUGS, and CORTICOSTEROIDS may help, as can SODIUM CROMOGLYCATE inhaled regularly during the pollen season. A desensitisation course to a particular allergen sometimes provides long-term relief.

Atrophic rhinitis is caused by a deterioration in the nasal mucous membrane as a result of chronic bacterial infection, nasal surgery or AGEING. Symptoms include persistent nasal infection and discharge and loss of sense of smell. ANTIBIOTICS and, in some cases, OESTROGENS alleviate the symptoms.

Hypertrophic rhinitis results from repeated nasal infection, and is characterised by thickened nasal membranes and congestion of the nasal veins. Removal of thickened mucosa may help severe cases.

Vasomotor rhinitis occurs when the mucosa becomes oversensitive to stimuli such as pollutants, temperature changes or certain foods or medicines. It may occur as a result of emotional disturbances and is common in pregnancy.

Viral rhinitis occurs as a result of infection by the common cold virus; treatment is symptomatic. Sinusitis is sometimes a complication.... Medical Dictionary

OBSESSIVE COMPULSIVE DISORDER

Medical Dictionary

A mental-health problem which will be experienced at some time by up to 3 per cent of adults. The main feature is the occurrence of spontaneous intrusive thoughts that cause intense anxiety. Many of these thoughts prompt urges, or compulsions, to carry out particular actions in order to reduce the anxiety. One of the commonest obsessions is a fear of dirt and contamination that prompts compulsive cleaning or repeated and unnecessary handwashing. (See MENTAL ILLNESS.)... Medical Dictionary

OTHER DISORDERS OF THE GALL-BLADDER

Medical Dictionary

These are rare. POLYPS may form and, if symptomatic, should be removed. Malignant change is rare. CARCINOMA of the gall-bladder is a disease of the elderly and is almost exclusively associated with gall-stones. By the time such a cancer has produced symptoms, the prognosis is bleak: 80 per cent of these patients die within one year of diagnosis. If the tumour is discovered early, 60 per cent of patients will survive ?ve years.... Medical Dictionary

PANCREAS, DISORDERS OF

Medical Dictionary

Diabetes See DIABETES MELLITUS.

Pancreatic cancer The incidence of pancreatic cancer is rising: around 7,000 cases are now diagnosed annually in the UK, accounting for 1–2 per cent of all malignancies. There is an established association with heavy cigarette-smoking, and the cancer is twice as common in patients with diabetes mellitus as compared with the general population. Cancer of the pancreas is hard to diagnose; by the time symptoms occur the tumour may be di?cult to treat surgically – with PALLIATIVE bypass surgery the only procedure.

Chronic pancreatitis may be painless; it leads to pancreatic failure causing MALABSORPTION SYNDROME and diabetes mellitus, and the pancreas becomes calci?ed with shadowing on X-RAYS. The malabsorption is treated by a low-fat diet with pancreatic enzyme supplements; the diabetes with insulin; and pain is treated appropriately. Surgery may be required.

Acute pancreatitis An uncommon disease of the pancreas which may start gradually or suddenly, usually accompanied by severe abdominal pain which often radiates through to the back. Biliary tract disease and alcohol account for 80 per cent of patients admitted with acute pancreatitis, while other causes include drugs (see AZATHIOPRINE and DIURETICS) and infections such as MUMPS. Patients are acutely ill with TACHYCARDIA, fever and low blood pressure; many go into SHOCK. The condition may be mistaken for a perforated PEPTIC ULCER, except that in acute pancreatitis the blood concentration of AMYLASE is raised. The main complication is the formation of a PSEUDOCYST. Treatment includes intravenous feeding, ANTICHOLINERGIC drugs and ANALGESICS. Regular measurements of blood GLUCOSE, CALCIUM, amylase and blood gases are required. Abdominal ULTRASOUND may identify gall-stones (see under GALL-BLADDER, DISEASES OF). If the patient deteriorates, he or she should be admitted for intensive care as haemorrhagic pancreatic necrosis may be developing. LAPAROTOMY and DEBRIDEMENT may be called for. Mortality is 5–10%.... Medical Dictionary

PERSONALITY DISORDER

Medical Dictionary

Condition in which the individual fails to learn from experience or to adapt to changes. The outcome is impaired social functioning and personal distress. There are three broad overlapping groups. One group is characterised by eccentric behaviour with paranoid or schizoid overtones. The second group shows dramatic and emotional behaviour with self-centredness and antisocial behaviour as typical components of the disorder. In the third group, anxiety and fear are the main characteristics, which are accompanied by dependency and compulsive behaviour. These disorders are not classed as illnesses but psychotherapy and behavioural therapy may help. The individuals a?ected are notoriously resistant to any help that is o?ered, tending to blame other people, circumstances or bad luck for their persistent di?culties. (See MENTAL ILLNESS; MULTIPLE PERSONALITY DISORDER; MUNCHAUSEN’S SYNDROME.)... Medical Dictionary

PITUITARY-LINKED DISORDERS

Medical Dictionary

ACROMEGALY or gigantism is the result of the overactivity of, or tumour formation of cells in, the adenohypophysis which produces GROWTH HORMONE (see also PITUITARY GLAND). If this overactivity occurs after growth has ceased, acromegaly arises, in which there is gross overgrowth of the ears, nose, jaws, and hands and feet. DWARFISM may be due to lack of growth hormone.

DIABETES INSIPIDUS, a condition characterised by the passing of a large volume of URINE every day, is due to lack of the antidiuretic hormone (see VASOPRESSIN). Enhanced production of the ADRENOCORTICOTROPHIC HORMONE (ACTH) leads to CUSHING’S SYNDROME. Excessive production of PROLACTIN by micro or macro adenomas (benign tumours) leads to hyperprolactinaemia and consequent AMENORRHOEA and GALACTORRHOEA. Some adenomas do not produce any hormone but cause e?ects by damaging the pituitary cells and inhibiting their hormone production.

The most sensitive cells to extrinsic pressure are the gonadotrophin-producing cells and the growth-hormone producing cells, so that if the tumour occurs in childhood, growth hormone will be suppressed and growth will slow. Gonadotrophin hormone suppression will prevent the development of puberty and, if the tumour occurs after puberty, will result in amenorrhoea in the female and lack of LIBIDO in both sexes. The thyroid-stimulating hormone cells are the next to su?er and the pressure e?ects on these cells will result in hypothyroidism (see under THYROID GLAND, DISEASES OF).

Fortunately the ACTH-producing cells are the most resistant to extrinsic pressure and this is teleologically sound as ACTH is the one pituitary hormone that is essential to life. However, these cells can su?er damage from intracellular tumours, and adrenocortical insu?ciency is not uncommon.

Information about these disorders may be obtained from the Pituitary Foundation.... Medical Dictionary

POST-TRAUMATIC STRESS DISORDER (PTSD)

Medical Dictionary

A term introduced to PSYCHIATRY in 1980 after the Vietnam War. It is one of several psychiatric disorders that can develop in people exposed to severe trauma, such as a major physical injury, participation in warfare, assault or rape, or any event in which there is major loss of life or a threat of loss of life. Most people exposed to trauma do not develop psychiatric disorder; however, some develop immediate distress and, occasionally, the reaction can be delayed for many months. Someone with PTSD has regular recurrences of memories or images of the stressful event (‘?ashbacks’), especially when reminded of it. Insomnia, feelings of guilt and isolation, an inability to concentrate and irritability may result. DEPRESSION is very common. Support from friends and family is probably the best management, but those who do not recover quickly can be helped by antidepressants and psychological treatments such as COGNITIVE BEHAVIOUR THERAPY. Over the past few years, PTSD has featured increasingly in compensation litigation.... Medical Dictionary

RETINA, DISORDERS OF

Medical Dictionary

See EYE, DISORDERS OF.... Medical Dictionary

SEASONAL AFFECTIVE DISORDER SYNDROME

Medical Dictionary

Known colloquially as SADS, this is a disorder in which an a?ected individual’s mood changes with the seasons. He or she is commonly depressed in winter, picking up again in the spring. The diagnosis is controversial and its prevalence is not known. The mood-change is probably related to light, with MELATONIN playing a key role. (See also MENTAL ILLNESS.)... Medical Dictionary

SLEEP, DISORDERS OF

Medical Dictionary

There are three main groups of SLEEP disorders:

Parasomnias These include medical disorders such as ASTHMA, ANGINA PECTORIS or EPILEPSY which are made worse by sleep, and a range of behavioural alterations which are usually related to a speci?c sleep stage or to a change from one state of sleep to another. Sleepwalking, night terrors, and nightmares are examples.

Insomnia Insomnia is de?ned as a di?culty in initiating or maintaining sleep. It a?ects around 15 per cent of the population at any one time, and is often due to a poor pre-sleep routine (e.g. taking excessive stimulants such as ca?eine); unsatisfactory sleep due to poor environments such as an uncomfortable bed or a cold or noisy bedroom; anxiety and/or depression; or occasionally to a physical problem – for example, pain – or a medical disorder associated with sleep such as obstructive SLEEP APNOEAS or periodic limb movements.

Excessive daytime sleepiness This is usually due to sleep deprivation caused either by inadequate duration of sleep, or by poor quality of sleep. The individual’s lifestyle is often a cause and modi?cation of this may relieve the problem. Other common causes of excessive daytime sleepiness are depression, obstructive sleep apnoeas, periodic limb movements, excessive alcohol or other drug intake, and, less commonly, NARCOLEPSY.... Medical Dictionary

SPEECH DISORDERS

Medical Dictionary

These may be of physical or psychological origin – or a combination of both. Di?culties may arise at various stages of development: due to problems during pregnancy; at birth; caused by childhood illnesses; or as a result of delayed development. Congenital defects such as CLEFT PALATE or lip may make speech unintelligible until major surgery is performed, thus discouraging talking and delaying development. Recurrent ear infections may make hearing dif?cult; the child’s experience of speech is thus limited, with similar results. Childhood DYSPHASIA occurs if the language-development area of the BRAIN develops abnormally; specialist education and SPEECH THERAPY may then be required.

Dumbness is the inability to pronounce the sounds that make up words. DEAFNESS is the most important cause, being due to a congenital brain defect, or acquired brain disease, such as tertiary SYPHILIS. When hearing is normal or only mildly impaired, dumbness may be due to a structural defect such as tongue-tie or enlarged tonsils and adenoids, or to ine?cient voice control, resulting in lisping or lalling. Increased tension is a common cause of STAMMERING; speech disorders may occasionally be of psychological origin.

Normal speech may be lost in adulthood as a result of a STROKE or head injury. Excessive use of the voice may be an occupational hazard; and throat cancer may require a LARYNGECTOMY, with subsequent help in communication. Severe psychiatric disturbance may be accompanied by impaired social and communication skills. (See also VOICE AND SPEECH.)

Treatment The underlying cause of the problem should be diagnosed as early as possible; psychological and other specialist investigations should be carried out as required, and any physical defect should be repaired. People who are deaf and unable to speak should start training in lip-reading as soon as possible, and special educational methods aimed at acquiring a modulated voice should similarly be started in early childhood – provided by the local authority, and continued as required. Various types of speech therapy or PSYCHOTHERAPY may be appropriate, alone or in conjunction with other treatments, and often the ?nal result may be highly satisfying, with a good command of language and speech being obtained.

Help and advice may be obtained from AFASIC (Unlocking Speech and Language).... Medical Dictionary

THOUGHT DISORDERS

Medical Dictionary

Thought is a mental activity by which people reason, solve problems, form judgements and communicate with each other by speech, writing and behaviour. Disturbances of thought are re?ected in how a person communicates: the normal logic of thought is broken up and a person may randomly move from one subject to another. SCHIZOPHRENIA is a mental illness characterised by thought disorder. Confusion, DEMENTIA, DEPRESSION and MANIA are other conditions in which thought disorders may be a marked feature. (See also MENTAL ILLNESS.)... Medical Dictionary

TONGUE, DISORDERS OF

Medical Dictionary

Conditions of the tongue At rest, the TONGUE touches all the lower teeth and is slightly arched from side to side. It has a smooth surface with a groove in the middle and an even but de?nite edge. It is under voluntary control and the tip can be moved in all directions.

Ankyloglossia or tongue-tie is a rare disorder in which the frenum or band connecting the lower surface of the tongue to the ?oor of the mouth is so short or tight that the tongue cannot be protruded. Surgery can remedy the defect. It is easy to overdiagnose and is not a common cause of di?culty in feeding at birth or speech defects in infancy.

Gross enlargement of the tongue can make speech indistinct or make swallowing and even breathing di?cult. This is known as macroglossia and may be such that the tongue is constantly protruded from the mouth. The cause may be CONGENITAL, as in severe cases of DOWN’S (DOWN) SYNDROME, or it may occur as a result of ACROMEGALY or be due to abnormal deposits as in AMYLOIDOSIS.

A marked tremor of the tongue when protruded may be seen in various neurological diseases, but may be caused by alcoholism.

After a STROKE involving the motor nerve centre, the control of one side of the tongue musculature will be lost. This will result in the protruded tongue pointing to the side of the body which is paralysed. The sense of taste on one side of the tongue may also be lost in some diseases of the brain and facial nerve.

The presence of fur on the tongue may be obvious and distressing. This is due to thickening of the super?cial layers of the tongue which may appear like hairs which trap food debris and become discoloured. Furring is common during fever and as a result of mouth-breathing and smoking.

In some conditions the tongue may appear dry, red and raw (GLOSSITIS). An in?amed beefy tongue is characteristic of pellagra, a disease caused by de?ciency of NICOTINIC ACID in the diet. A magenta-coloured tongue may be seen when there is a lack of RIBOFLAVIN.

Ulcers of the tongue are similar to those elsewhere in the mouth. The most common are aphthous ulcers which are small, red and painful and last for about ten days. They are associated with stress, mild trauma (such as from jagged teeth), and occasionally with folic acid and vitamin B12 de?ciency. Ulcers of the tongue are sometimes found in patients with chronic bowel disease.... Medical Dictionary

UPPER LIMB DISORDERS

Medical Dictionary

A group of injuries resulting from overuse of a part of the limb. One example is TENNIS ELBOW (epicondylitis) caused by in?ammation of the tendon attaching the extensor muscles of the forearm to the humerus because of overuse of the muscles. Overuse of the shoulder muscles may cause in?ammation and pain around the joint. Perhaps the best-known example is repetitive strain injury (RSI) a?ecting keyboard workers and musicians: the result is pain in and weakness of the wrists and ?ngers. This has a?ected thousands of people and been the subject of litigation by employees against their employers. Working practices have been improved and the complaint is now being recognised at an early stage. Treatment includes PHYSIOTHERAPY, but some su?erers have been obliged to give up their work.... Medical Dictionary

VISION, DISORDERS OF

Medical Dictionary

The list of disorders resulting in poor or dim vision is huge. Disturbance of vision can result from an uncorrected refractive error, disease or injury of the cornea, iris, lens, vitreous, retina, choroid or sclera of the EYE. It may also result from disease or injury to the structures comprising the visual pathway from the retina to the occipital cortex (see VISION – Pathway of light from the eye to the brain) and from lesions of the structures around the eye – for example, swollen lids, drooping eyelids. (See EYE, DISORDERS OF.)... Medical Dictionary