The control centre of the whole nervous system is the brain, which is located in the skull or cranium. As well as controlling the nervous system it is the organ of thought, speech and emotion. The central nervous system controls the body’s essential functions such as breathing, body temperature (see HOMEOSTASIS) and the heartbeat. The body’s various sensations, including sight, hearing, touch, pain, positioning and taste, are communicated to the CNS by nerves distributed throughout the relevant tissues. The information is then sorted and interpreted by specialised areas in the brain. In response these initiate and coordinate the motor output, triggering such ‘voluntary’ activities as movement, speech, eating and swallowing. Other activities – for example, breathing, digestion, heart contractions, maintenance of BLOOD PRESSURE, and ?ltration of waste products from blood passing through the kidneys – are subject to involuntary control via the autonomic system. There is, however, some overlap between voluntary and involuntary controls.... brain
Touch sense proper, by which we perceive a touch or stroke and estimate the size and shape of bodies with which we come into contact, but which we do not see.
Pressure sense, by which we judge the heaviness of weights laid upon the skin, or appreciate the hardness of objects by pressing against them.
Heat sense, by which we perceive that an object is warmer than the skin.
Cold sense, by which we perceive that an object touching the skin is cold.
Pain sense, by which we appreciate pricks, pinches and other painful impressions.
Muscular sensitiveness, by which the painfulness of a squeeze is perceived. It is produced probably by direct pressure upon the nerve-?bres in the muscles.
Muscular sense, by which we test the weight of an object held in the hand, or gauge the amount of energy expended on an e?ort.
Sense of locality, by which we can, without looking, tell the position and attitude of any part of the body.
Common sensation, which is a vague term used to mean composite sensations produced by several of the foregoing, like tickling, or creeping, and the vague sense of well-being or the reverse that the mind receives from internal organs. (See the entry on PAIN.)
The structure of the end-organs situated in the skin, which receive impressions from the outer world, and of the nerve-?bres which conduct these impressions to the central nervous system, have been described under NERVOUS SYSTEM. (See also SKIN.)
Touch affects the Meissner’s or touch corpuscles placed beneath the epidermis; as these di?er in closeness in di?erent parts of the skin, the delicacy of the sense of touch varies greatly. Thus the points of a pair of compasses can be felt as two on the tip of the tongue when separated by only 1 mm; on the tips of the ?ngers they must be separated to twice that distance, whilst on the arm or leg they cannot be felt as two points unless separated by over 25 mm, and on the back they must be separated by more than 50 mm. On the parts covered by hair, the nerves ending around the roots of the hairs also take up impressions of touch.
Pressure is estimated probably through the same nerve-endings and nerves that have to do with touch, but it depends upon a di?erence in the sensations of parts pressed on and those of surrounding parts. Heat-sense, cold-sense and pain-sense all depend upon di?erent nerve-endings in the skin; by using various tests, the skin may be mapped out into a mosaic of little areas where the di?erent kinds of impressions are registered. Whilst the tongue and ?nger-tips are the parts most sensitive to touch, they are comparatively insensitive to heat, and can easily bear temperatures which the cheek or elbow could not tolerate. The muscular sense depends upon the sensory organs known as muscle-spindles, which are scattered through the substance of the muscles, and the sense of locality is dependent partly upon these and partly upon the nerves which end in tendons, ligaments and joints.
Disorders of the sense of touch occur in various diseases. HYPERAESTHESIA is a condition in which there is excessive sensitiveness to any stimulus, such as touch. When this reaches the stage when a mere touch or gentle handling causes acute pain, it is known as hyperalgesia. It is found in various diseases of the SPINAL CORD immediately above the level of the disease, combined often with loss of sensation below the diseased part. It is also present in NEURALGIA, the skin of the neuralgic area becoming excessively tender to touch, heat or cold. Heightened sensibility to temperature is a common symptom of NEURITIS. ANAESTHESIA, or diminution of the sense of touch, causing often a feeling of numbness, is present in many diseases affecting the nerves of sensation or their continuations up the posterior part of the spinal cord. The condition of dissociated analgesia, in which a touch is quite well felt, although there is complete insensibility to pain, is present in the disease of the spinal cord known as SYRINGOMYELIA, and a?ords a proof that the nerve-?bres for pain and those for touch are quite separate. In tabes dorsalis (see SYPHILIS) there is sometimes loss of the sense of touch on feet or arms; but in other cases of this disease there is no loss of the sense of touch, although there is a complete loss of the sense of locality in the lower limbs, thus proving that these two senses are quite distinct. PARAESTHESIAE are abnormal sensations such as creeping, tingling, pricking or hot ?ushes.... touch
Information is collected by millions of sense receptors found throughout body tissues and in special sense organs, such as the eye.
Certain sensory information, mainly that from the special sense organs and skin receptors, enters the sensory cortex of the brain, where sensations are consciously perceived.
Other types of sensory information, for example about body posture, are processed elsewhere and do not produce conscious sensation.... sensation
Each thalamus relays sensory information flowing into the brain. Some basic sensations, such as pain, may reach consciousness within the thalamus. Other types of sensory information are processed and relayed to parts of the cerebral cortex (outer layer of the brain), where sensations are perceived.
The thalamus seems to act as a filter by selecting only information of particular importance. Certain centres in the thalamus may also play a part in longterm memory.... thalamus
Treatment consists of large doses of vitamin B1 – orally or intramuscularly; a diet containing other vitamins of the B group; and rest.
Infantile beriberi This is the result of maternal thiamine de?ciency; although the mother is not necessarily affected, the breast-fed baby may develop typical signs (see above). Optic and third cranial, and recurrent laryngeal nerves may be affected; encephalopathy can result in convulsions, coma and death.... beriberi
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 suffer 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 affects 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 affected 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-effects (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 affected 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 affecting 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.... bone, disorders of
The power is impaired in various diseases, such as LOCOMOTOR ATAXIA. It is tested by making the patient shut their eyes, moving their hand in various directions, and then telling them to bring the point of the fore?nger steadily to the tip of the nose – or by other simple movements.... coordination
as the organ of the sense of taste, and as an organ provided with a delicate sense of touch; and
to play a part in the production of speech. (See VOICE AND SPEECH.) It is usual to classify any taste as: sweet, bitter,
salt and acid, since ?ner distinctions are largely dependent upon the sense of smell. The loss of keenness in taste brought about by a cold in the head, or even by holding the nose while swallowing, is well known. Sweet tastes seem to be best appreciated by the tip of the tongue, acids on its edges, and bitters at the back. There are probably di?erent nerve-?bres and end-organs for the di?erent varieties of taste. Many tastes depend upon the ordinary sensations of the tongue.
Like other sensations, taste can be very highly educated for a time, as in tea-tasters and wine-tasters, but this special adaptation is lost after some years.... functions the chief uses of the tongue are:
Psychiatrists like to categorise mental illnesses because mental signs and symptoms do occur together in clusters or syndromes, each tending to respond to certain treatments. The idea that illnesses can be diagnosed simply by recognising their symptom patterns may not seem very scienti?c in these days of high technology. For most common mental illnesses, however, this is the only method of diagnosis; whatever is going wrong in the brain is usually too poorly understood and too subtle to show up in laboratory tests or computed tomography scans of the brain. And symptom-based definitions of mental illnesses are, generally, a lot more meaningful than the vague lay term ‘nervous breakdown’, which is used to cover an attack of anything from AGORAPHOBIA to total inability to function.
There is still a lot to learn about the workings of the brain, but psychiatry has developed plenty of practical knowledge about the probable causes of mental illness, ways of relieving symptoms, and ways of aiding recovery. Most experts now believe that mental illnesses generally arise from di?erent combinations of inherited risk and psychological STRESS, sometimes with additional environmental exposure – for example, viruses, drugs or ALCOHOL.
The range of common mental illnesses includes anxiety states, PHOBIA, DEPRESSION, alcohol and drug problems, the EATING DISORDERS anorexia and bulimia nervosa, MANIC DEPRESSION, SCHIZOPHRENIA, DEMENTIA, and a group of problems related to coping with life that psychiatrists call personality disorders.
Of these mental illnesses, dementia is the best understood. It is an irreversible and fatal form of mental deterioration (starting with forgetfulness and eventually leading to severe failure of all the brain’s functions), caused by rapid death of brain cells and consequent brain shrinkage. Schizophrenia is another serious mental illness which disrupts thought-processes, speech, emotions and perception (how the brain handles signals from the ?ve senses). Manic depression, in which prolonged ‘highs’ of extremely elevated mood and overexcitement alternate with abject misery, has similar effects on the mental processes. In both schizophrenia and manic depression the sufferer loses touch with reality, develops unshakeable but completely unrealistic ideas (delusions), and hallucinates (vividly experiences sensations that are not real, e.g. hears voices when there is nobody there). This triad of symptoms is called psychosis and it is what lay people, through fear and lack of understanding, sometimes call lunacy, madness or insanity.
The other mental illnesses mentioned above are sometimes called neuroses. But the term has become derogatory in ordinary lay language; indeed, many people assume that neuroses are mild disorders that only affect weak people who cannot ‘pull themselves together’, while psychoses are always severe. In reality, psychoses can be brief and reversible and neuroses can cause lifelong disability.
However de?ned and categorised, mental illness is a big public-health problem. In the UK, up to one in ?ve women and around one in seven men have had mental illness. About half a million people in Britain suffer from schizophrenia: it is three times commoner than cancer. And at any one time, up to a tenth of the adult population is ill with depression.
Treatment settings Most people with mental-health problems get the help they need from their own family doctor(s), without ever seeing a psychiatrist. General practictitioners in Britain treat nine out of ten recognised mental-health problems and see around 12 million adults with mental illness each year. Even for the one in ten of these patients referred to psychiatrists, general practitioners usually handle those problems that continue or recur.
Psychiatrists, psychiatric nurses, social workers, psychologists, counsellors and therapists often see patients at local doctors’ surgeries and will do home visits if necessary. Community mental-health centres – like general-practice health centres but catering solely for mental-health problems – o?er another short-cut to psychiatric help. The more traditional, and still more common, route to a psychiatrist for many people, however, is from the general practititioner to a hospital outpatient department.
Specialist psychiatric help In many ways, a visit to a psychiatrist is much like any trip to a hospital doctor – and, indeed, psychiatric clinics are often based in the outpatient departments of general hospitals. First appointments with psychiatrists can last an hour or more because the psychiatrist – and sometimes other members of the team such as nurses, doctors in training, and social workers – need to ask lots of questions and record the whole consultation in a set of con?dential case notes.
Psychiatric assessment usually includes an interview and an examination, and is sometimes backed up by a range of tests. The interview begins with the patient’s history – the personal story that explains how and, to some extent, why help is needed now. Mental-health problems almost invariably develop from a mixture of causes – emotional, social, physical and familial – and it helps psychiatrists to know what the people they see are normally like and what kind of lives they have led. These questions may seem unnecessarily intrusive, but they allow psychiatrists to understand patients’ problems and decide on the best way to help them.
The next stage in assessment is the mental-state examination. This is how psychiatrists examine minds, or at least their current state. Mental-state examination entails asking more questions and using careful observation to assess feelings, thoughts and mental symptoms, as well as the way the mind is working (for example, in terms of memory and concentration). During ?rst consultations psychiatrists usually make diagnoses and explain them. The boundary between a life problem that will clear up spontaneously and a mental illness that needs treatment is sometimes quite blurred; one consultation may be enough to put the problem in perspective and help to solve it.
Further assessment in the clinic may be needed, or some additional tests. Simple blood tests can be done in outpatient clinics but other investigations will mean referral to another department, usually on another day.
Further assessment and tests
PSYCHOLOGICAL TESTS Psychologists work in or alongside the psychiatric team, helping in both assessment and treatment. The range of psychological tests studies memory, intelligence, personality, perception and capability for abstract thinking. PHYSICAL TESTS Blood tests and brain scans may be useful to rule out a physical illness causing psychological symptoms. SOCIAL ASSESSMENT Many patients have social diffculties that can be teased out and helped by a psychiatric social worker. ‘Approved social workers’ have special training in the use of the Mental Health Act, the law that authorises compulsory admissions to psychiatric hospitals and compulsory psychiatric treatments. These social workers also know about all the mental-health services o?ered by local councils and voluntary organisations, and can refer clients to them. The role of some social workers has been widened greatly in recent years by the expansion of community care. OCCUPATIONAL THERAPY ASSESSMENT Mental-health problems causing practical disabilities – for instance, inability to work, cook or look after oneself – can be assessed and helped by occupational therapists.
Treatment The aims of psychiatric treatment are to help sufferers shake o?, or at least cope with, symptoms and to gain or regain an acceptable quality of life. A range of psychological and physical treatments is available.
COUNSELLING This is a widely used ‘talking cure’, particularly in general practice. Counsellors listen to their clients, help them to explore feelings, and help them to ?nd personal and practical solutions to their problems. Counsellors do not probe into clients’ pasts or analyse them. PSYCHOTHERAPY This is the best known ‘talking cure’. The term psychotherapy is a generalisation covering many di?erent concepts. They all started, however, with Sigmund Freud (see FREUDIAN THEORY), the father of modern psychotherapy. Freud was a doctor who discovered that, as well as the conscious thoughts that guide our feelings and actions, there are powerful psychological forces of which we are not usually aware. Applying his theories to his patients’ freely expressed thoughts, Freud was able to cure many illnesses, some of which had been presumed completely physical. This was the beginning of individual analytical psychotherapy, or PSYCHOANALYSIS. Although Freud’s principles underpin all subsequent theories about the psyche, many di?erent schools of thought have emerged and in?uenced psychotherapists (see ADLER; JUNGIAN ANALYSIS; PSYCHOTHERAPY). BEHAVIOUR THERAPY This springs from theories of human behaviour, many of which are based on studies of animals. The therapists, mostly psychologists, help people to look at problematic patterns of behaviour and thought, and to change them. Cognitive therapy is very e?ective, particularly in depression and eating disorders. PHYSICAL TREATMENTS The most widely used physical treatments in psychiatry are drugs. Tranquillising and anxiety-reducing BENZODIAZEPINES like diazepam, well known by its trade name of Valium, were prescribed widely in the 1960s and 70s because they seemed an e?ective and safe substitute for barbiturates. Benzodiazepines are, however, addictive and are now recommended only for short-term relief of anxiety that is severe, disabling, or unacceptably distressing. They are also used for short-term treatment of patients drying out from alcohol.
ANTIDEPRESSANT DRUGS like amitriptyline and ?uoxetine are given to lift depressed mood and to relieve the physical symptoms that sometimes occur in depression, such as insomnia and poor appetite. The side-effects of antidepressants are mostly relatively mild, when recommended doses are not exceeded – although one group, the monoamine oxidase inhibitors, can lead to sudden and dangerous high blood pressure if taken with certain foods.
Manic depression virtually always has to be treated with mood-stabilising drugs. Lithium carbonate is used in acute mania to lower mood and stop psychotic symptoms; it can also be used in severe depression. However lithium’s main use is to prevent relapse in manic depression. Long-term unwanted effects may include kidney and thyroid problems, and short-term problems in the nervous system and kidney may occur if the blood concentration of lithium is too high – therefore it must be monitored by regular blood tests. Carbamazepine, a treatment for EPILEPSY, has also been found to stabilise mood, and also necessitates blood tests.
Antipsychotic drugs, also called neuroleptics, and major tranquillisers are the only e?ective treatments for relieving serious mental illnesses with hallucinations and delusions. They are used mainly in schizophrenia and include the short-acting drugs chlorpromazine and clozapine as well as the long-lasting injections given once every few weeks like ?uphenazine decanoate. In the long term, however, some of the older antipsychotic drugs can cause a brain problem called TARDIVE DYSKINESIA that affects control of movement and is not always reversible. And the antipsychotic drugs’ short-term side-effects such as shaking and sti?ness sometimes have to be counteracted by other drugs called anticholinergic drugs such as procyclidine and benzhexol. Newer antipsychotic drugs such as clozapine do not cause tardive dyskinesia, but clozapine cannot be given as a long-lasting injection and its concentration in the body has to be monitored by regular blood tests to avoid toxicity. OTHER PHYSICAL TREATMENTS The other two physical treatments used in psychiatry are particularly controversial: electroconvulsive therapy (ECT) and psychosurgery. In ECT, which can be life-saving for patients who have severe life-threatening depression, a small electric current is passed through the brain to induce a ?t or seizure. Before the treatment the patient is anaesthetised and given a muscle-relaxing injection that reduces the magnitude of the ?t to a slight twitching or shaking. Scientists do not really understand how ECT works, but it does, for carefully selected patients. Psychosurgery – operating on the brain to alleviate psychiatric illness or di?cult personality traits – is extremely uncommon these days. Stereo-tactic surgery, in which small cuts are made in speci?c brain ?bres under X-ray guidance, has super-seded the more generalised lobotomies of old. The Mental Health Act 1983 ensures that psychosurgery is performed only when the patient has given fully informed consent and a second medical opinion has agreed that it is necessary. For all other psychiatric treatments (except another rare treatment, hormone implantation for reducing the sex drive of sex o?enders), either consent or a second opinion is needed – not both. TREATMENT IN HOSPITAL Psychiatric wards do not look like medical or surgical wards and sta? may not wear uniforms. Patients do not need to be in their beds during the day, so the beds are in separate dormitories. The main part of most wards is a living space with a day room, an activity and television room, quiet rooms, a dining room, and a kitchen. Ward life usually has a certain routine. The day often starts with a community meeting at which patients and nurses discuss issues that affect the whole ward. Patients may go to the occupational therapy department during the day, but there may also be some therapy groups on the ward, such as relaxation training. Patients’ symptoms and problems are assessed continuously during a stay in hospital. When patients seem well enough they are allowed home for trial periods; then discharge can be arranged. Patients are usually followed up in the outpatient clinic at least once.
TREATING PATIENTS WITH ACUTE PSYCHIATRIC ILLNESS Psychiatric emergencies – patients with acute psychiatric illness – may develop from psychological, physical, or practical crises. Any of these crises may need quick professional intervention. Relatives and friends often have to get this urgent help because the sufferer is not ?t enough to do it or, if psychotic, does not recognise the need. First, they should ring the person’s general practitioner. If the general practitioner is not available and help is needed very urgently, relatives or friends should phone the local social-services department and ask for the duty social worker (on 24-hour call). In a dire emergency, the police will know what to do.
Any disturbed adult who threatens his or her own or others’ health and safety and refuses psychiatric help may be moved and detained by law. The Mental Health Act of 1983 authorises emergency assessment and treatment of any person with apparent psychiatric problems that ful?l these criteria.
Although admission to hospital may be the best solution, there are other ways that psychiatric services can respond to emergencies. In some districts there are ‘crisis intervention’ teams of psychiatrists, nurses, and social workers who can visit patients urgently at home (at a GP’s request) and, sometimes, avert unnecessary admission. And research has shown that home treatment for a range of acute psychiatric problems can be e?ective.
LONG-TERM TREATMENT AND COMMUNITY CARE Long-term treatment is often provided by GPs with support and guidance from psychiatric teams. That is ?ne for people whose problems allow them to look after themselves, and for those with plenty of support from family and friends. But some people need much more intensive long-term treatment and many need help with running their daily lives.
Since the 1950s, successive governments have closed the old psychiatric hospitals and have tried to provide as much care as possible outside hospital – in ‘the community’. Community care is e?ective as long as everyone who needs inpatient care, or residential care, can have it. But demand exceeds supply. Research has shown that some homeless people have long-term mental illnesses and have somehow lost touch with psychiatric services. Many more have developed more general long-term health problems, particularly related to alcohol, without ever getting help.
The NHS and Community Care Act 1990, in force since 1993, established a new breed of professionals called care managers to assess people whose long-term illnesses and disabilities make them unable to cope completely independently with life. Care managers are given budgets by local councils to assess people’s needs and to arrange for them tailor-made packages of care, including services like home helps and day centres. But co-ordination between health and social services has sometimes failed – and resources are limited – and the government decided in 1997 to tighten up arrangements and pool community-care budgets.
Since 1992 psychiatrists have had to ensure that people with severe mental illnesses have full programmes of care set up before discharge from hospital, to be overseen by named key workers. And since 1996 psychiatrists have used a new power called Supervised Discharge to ensure that the most vulnerable patients cannot lose touch with mental-health services. There is not, however, any law that allows compulsory treatment in the community.
There is ample evidence that community care can work and that it need not cost more than hospital care. Critics argue, however, that even one tragedy resulting from inadequate care, perhaps a suicide or even a homicide, should reverse the march to community care. And, according to the National Schizophrenia Fellowship, many of the 10–15 homicides a year carried out by people with severe mental illnesses result from inadequate community care.
Further information can be obtained from the Mental Health Act Commission, and from MIND, the National Association for Mental Health. MIND also acts as a campaigning and advice organisation on all aspects of mental health.... mental illness
In hemiplegia, or PARALYSIS down one side of the body following a STROKE, the person drags the paralysed leg.
Steppage gait occurs in certain cases of alcoholic NEURITIS, tertiary SYPHILIS (tabes) and other conditions where the muscles that raise the foot are weak so that the toes droop. The person bends the knee and lifts the foot high, so that the toes may clear obstacles on the ground. (See DROP-FOOT.)
In LOCOMOTOR ATAXIA or tabes dorsalis, the sensations derived from the lower limbs are blunted, and consequently the movements of the legs are uncertain and the heels planted upon the ground with unnecessary force. When the person tries to turn or stands with the eyes shut, he or she may fall over. When they walk, they feel for the ground with a stick or keep their eyes constantly ?xed upon it.
In spastic paralysis the limbs are moved with jerks. The foot ?rst of all clings to the ground and then leaves it with a spasmodic movement, being raised much higher than is necessary.
In PARKINSONISM the movements are tremulous, and as the person takes very short steps, he or she has the peculiarity of appearing constantly to fall forwards, or to be chasing themselves.
In CHOREA the walk is bizarre and jerky, the affected child often seeming to leave one leg a step behind, and then, with a screwing movement on the other heel, go on again.
Psychologically based idiosyncracies of gait are usually of a striking nature, quite di?erent from those occuring in any neurological conditions. They tend to draw attention to the patient, and are worse when he or she is observed.... gait
The skin overlying the painful area may be red and tender, or blue, cold, and clammy.
Causalgia may be aggravated by light sensations, such as touch, or emotional factors.
In some cases, treatment with antidepressant drugs or anticonvulsant drugs may be effective.
A few people benefit from sympathectomy, an operation in which nerves are severed.... causalgia
Acute pain is caused by internal or external injury or disease. It warns the individual that harm or damage is occurring and stimulates them to take avoiding or protective action. With e?ective treatment of disease or injury and/or the natural healing process, the pain resolves – although some acute pain syndromes may develop into chronic pain (see below). Stimuli which are su?ciently intense potentially to damage tissue will cause the stimulation of speci?c receptors known as NOCICEPTORS. Damage to tissues releases substances which stimulate the nociceptors. On the surface of the body there is a high density of nociceptors, and each area of the body is supplied by nerves from a particular spinal segment or level: this allows the brain to localise the source of the pain accurately. Pain from internal structures and organs is more di?cult to localise and is often felt in some more super?cial structure. For example, irritation of the DIAPHRAGM is often felt as pain in the shoulder, as the nerves from both structures enter the SPINAL CORD at the same level (often the structures have developed from the same parts of the embryo). This is known as referred pain.
The impulses from nociceptors travel along nerves to the spinal cord. Within this there is modulation of the pain ‘messages’ by other incoming sensory modalities, as well as descending input from the brain (Melzack and Walls’ gate-control theory). This involves morphine-like molecules (the ENDORPHINS and ENKEPHALINS) amongst many other pain-transmitting and pain-modulating substances. The modi?ed input then passes up the spinal cord through the thalamus to the cerebral cortex. Thus the amount of pain ‘felt’ may be altered by the emotional state of the individual and by other incoming sensations. Once pain is perceived, then ‘action’ is taken; this involves withdrawal of the area being damaged, vocalisation, AUTONOMIC NERVOUS SYSTEM response and examination of the painful area. Analysis of the event using memory will occur and appropriate action be taken to reduce pain and treat the damage.
Chronic pain may be de?ned in several ways: for example, pain resistant to one month’s treatment, or pain persisting one month beyond the usual course of an acute illness or injury. Some doctors may also arbitrarily choose the ?gure of six months. Chronic pain di?ers from acute pain: the physiological response is di?erent and pain may either be caused by stimuli which do not usually cause the perception of pain, or may arise within nerves or the central nervous system with no apparent external stimulation. It seldom has a physiological protective function in the way acute pain has. Also, chronic pain may be self-perpetuating: if individuals gain a psychological advantage from having pain, they may continue to do so (e.g. gaining attention from family or health professionals, etc.). The nervous system itself alters when pain is long-standing in such a way that it becomes more sensitive to painful inputs and tends to perpetuate the pain.
Treatment The treatment of pain depends upon its nature and cause. Acute pain is generally treated by curing the underlying complaint and prescribing ANALGESICS or using local anaesthetic techniques (see ANAESTHESIA – Local anaesthetics). Many hospitals now have acute pain teams for the management of postoperative and other types of acute pain; chronic pain is often treated in pain clinics. Those involved may include doctors (in Britain, usually anaesthetists), nurses, psychologists and psychiatrists, physiotherapists and complementary therapists. Patients are usually referred from other hospital specialists (although some may be referred by GPs). They will usually have been given a diagnosis and exhausted the medical and surgical treatment of their underlying condition.
All the usual analgesics may be employed, and opioids are often used in the terminal treatment of cancer pain.
ANTICONVULSANTS and ANTIDEPRESSANT DRUGS are also used because they alter the transmission of pain within the central nervous system and may actually treat the chronic pain syndrome.
Many local anaesthetic techniques are used. Myofascial pain – pain affecting muscles and connective tissues – is treated by the injection of local anaesthetic into tender spots, and nerves may be blocked either as a diagnostic procedure or by way of treatment. Epidural anaesthetic injections are also used in the same way, and all these treatments may be repeated at intervals over many months in an attempt to cure or at least reduce the pain. For intractable pain, nerves are sometimes destroyed using injections of alcohol or PHENOL or by applying CRYOTHERAPY or radiofrequency waves. Intractable or terminal pain may be treated by destroying nerves surgically, and, rarely, the pain pathways within the spinal cord are severed by cordotomy (though this is generally only used in terminal care).
ACUPUNCTURE and TRANSCUTANEOUS ELECTRICAL NERVE STIMULATION (TENS) are used for a variety of pain syndromes, particularly myofascial or musculoskeletal pain. It is thought that they work by increasing the release of endorphins and enkephalins (see above). It is possible to implant electrodes within the epidural space to stimulate directly the nerves as they traverse this space before passing into the spinal cord.
Physiotherapy is often used, particularly in the treatment of chronic backache, where pain may be reduced by improving posture and strengthening muscles with careful exercises. Relaxation techniques and psychotherapy are also used both to treat chronic pain and to help patients cope better with their disability.
Some types of chronic pain are caused by injury to sympathetic nerves or may be relieved by interrupting conduction in sympathetic nerves. This may be done in several ways. The nerves may be blocked using local anaesthetic or permanently destroyed using alcohol, phenol or by surgery.
Many of these techniques may be used in the management of cancer pain. Opioid drugs are often used by a variety of routes and methods, and management of these patients concentrates on the control of symptoms and on providing a good quality of life.... pain
Symptoms There are headache, feverishness, general sensations like those of INFLUENZA, flushed face and bloodshot eyes, but no signs of CATARRH. The fever passes off in three days, but the patient may take some time to convalesce.
Treatment As there is no specific remedy, PROPHYLAXIS is important. This consists of the spraying of rooms with an insecticide such as GAMMEXANE; the application of insect repellents such as dimethyl phthalate to the exposed parts of the body (e.g. ankles, wrists and face), particularly at sunset; and the use of sandfly nets at night. Once the infection is acquired, treatment consists of rest in bed, light diet and aspirin and codeine.... sandfly fever
Structure
CORIUM The foundation layer. It overlies the subcutaneous fat and varies in thickness from 0·5–3.0 mm. Many nerves run through the corium: these have key roles in the sensations of touch, pain and temperature (see NEURON(E)). Blood vessels nourish the skin and are primarily responsible for regulating the body temperature. Hairs are bedded in the corium, piercing the epidermis (see below) to cover the skin in varying amounts in di?erent parts of the body. The sweat glands are also in the corium and their ducts lead to the surface. The ?brous tissue of the corium comprises interlocking white ?brous elastic bundles. The corium contains many folds, especially over joints and on the palms of hands and soles of feet with the epidermis following the contours. These are permanent throughout life and provide unique ?ngerprinting identi?cation. HAIR Each one has a root and shaft, and its varying tone originates from pigment scattered throughout it. Bundles of smooth muscle (arrectores pilorum) are attached to the root and on contraction cause the hair to stand vertical. GLANDS These occur in great numbers in the skin. SEBACEOUS GLANDS secrete a fatty substance and sweat glands a clear watery ?uid (see PERSPIRATION). The former are made up of a bunch of small sacs producing fatty material that reaches the surface via the hair follicle. Around three million sweat or sudoriparous glands occur all over the body surface; sited below the sebaceous glands they are unconnected to the hairs. EPIDERMIS This forms the outer layer of skin and is the cellular layer covering the body surface: it has no blood vessels and its thickness varies from 1 mm on the palms and soles to 0·1 mm on the face. Its outer, impervious, horny layer comprises several thicknesses of ?at cells (pierced only by hairs and sweat-gland openings) that are constantly rubbed o? as small white scales; they are replaced by growing cells from below. The next, clear layer forms a type of membrane below which the granular stratum cells are changing from their origins as keratinocytes in the germinative zone, where ?ne sensory nerves also terminate. The basal layer of the germinative zone contains melanocytes which produce the pigment MELANIN, the cause of skin tanning.
Nail A modi?cation of skin, being analagous to the horny layer, but its cells are harder and more adherent. Under the horny nail is the nail bed, comprising the well-vascularised corium (see above) and the germinative zone. Growth occurs at the nail root at a rate of around 0·5 mm a week – a rate that increases in later years of life.
Skin functions By its ability to control sweating and open or close dermal blood vessels, the skin plays a crucial role in maintaining a constant body temperature. Its toughness protects the body from mechanical injury. The epidermis is a two-way barrier: it prevents the entry of noxious chemicals and microbes, and prevents the loss of body contents, especially water, electrolytes and proteins. It restricts electrical conductivity and to a limited extent protects against ultraviolet radiation.
The Langerhans’ cells in the epidermis are the outposts of the immune system (see IMMUNITY), just as the sensory nerves in the skin are the outposts of the nervous system. Skin has a social function in its ability to signal emotions such as fear or anger. Lastly it has a role in the synthesis of vitamin D.... skin
Uses: Early American settlers and Indians claimed its power to prevent premature labour and miscarriage, prolonged painful labours and rigidity of the os. Indicated in labour with no expulsive effort and to counter false labour pains with bearing down sensations in the abdomen. Dr Farrington (Ellingwood’s Therapeutist) knew a single dose to arrest them after lasting several hours.
For persistent amenorrhoea and to increase menstrual flow; painful adolescent menses. Habitual abortion. Painful inflammation of the vagina, internally; and as a douche. Adolescent leucorrhoea. Acute rheumatic pains of the menopause. Combines well with Motherwort for rapid recovery after childbirth. Preparations. Thrice daily, or as dictated for an acute condition.
Powder: by capsule or for decoction: dose, 0.3-1g.
Liquid Extract BHP (1983): 1:1 in 70 per cent alcohol; dose, 0.5-1ml. Tincture. One to ten parts 70 per cent alcohol. Dose: 1-2ml.
Note: Chiefly used the latter half of pregnancy. ... blue cohosh
This nerve performs both sensory and motor functions.
It conveys sensations, especially taste, from the back of the tongue, regulates secretion of saliva by the parotid gland, and controls movement of the throat muscles.... glossopharyngeal nerve
As well as having an analgesic effect, heroin produces sensations of warmth, calmness, drowsiness, and a loss of concern for outside events. Long-term use of the drug causes tolerance and psychological and physical dependence (see drug dependence; heroin abuse). Sudden withdrawal produces shivering, abdominal cramps, diarrhoea, vomiting, and restlessness.... heroin
between about 400 and 700 nanometres. Different wavelengths produce sensations of violet, indigo, blue, green, yellow, orange, and red when they fall on the retina and stimulate nerve signals, which are processed in the brain.
As light falls on the retina, it strikes light-sensitive cells called rods and cones. The rods can detect all visible light, but only the cones can distinguish colour. There are 3 types of cones: red-sensitive, blue-sensitive, and green-sensitive. Each responds more strongly to a particular part of the light spectrum. Because the cones are most concentrated in a central area of the retina called the fovea, colour vision is most accurate for objects viewed directly and is poor at the edges of vision. When light hits a cone, it causes the cone to emit an electrical signal, which passes to the brain via the optic nerve. Colour perception requires a minimum level of light, below which everything is seen as shades of grey. (See also colour vision deficiency; eye; perception; vision.)... colour vision
Damage to the nerve may result from injury to the shoulder, a Colles’ fracture just above the wrist, or pressure on the nerve where it passes through the wrist (carpal tunnel syndrome).
Symptoms of damage include numbness and weakness in areas controlled by the nerve.... median nerve
Some cases of neuropathy have no obvious cause. Among specific causes are diabetes mellitus, dietary deficiencies, excessive alcohol consumption, and metabolic upsets such as uraemia.
Nerves may become acutely inflamed after a viral infection, and neuropathies may also result from autoimmune disorders, such as rheumatoid arthritis. Neuropathies may occur secondarily to cancerous tumours, or with lymphomas and leukaemias. There is also a group of inherited neuropathies, the most common being peroneal muscular atrophy.
The symptoms of neuropathy depend on whether it affects mainly sensory nerve fibres or mainly motor nerve fibres. Damage to sensory nerve fibres may cause numbness, tingling, sensations of cold, and pain. Damage to motor fibres may cause muscle weakness and muscle wasting. Damage to autonomic nerves may lead to blurred vision, impaired or absent sweating, faintness, and disturbance of gastric, intestinal, bladder, and sexual functioning.
To determine the extent of the damage, nerve conduction studies are carried out together with EMG tests, which record the electrical activity in muscles.
Diagnostic tests such as blood tests, MRI scans, and nerve or muscle biopsy may also be required.
When possible, treatment is aimed at the underlying cause.
If the cell bodies of the damaged nerve cells have not been destroyed, full recovery from neuropathy is possible.... neuropathy
Symptoms tend to come on at night in bed; they may also be triggered by prolonged sitting.
The condition tends to run in families and is common in middleaged women, people with rheumatoid arthritis, smokers, and during pregnancy.
The cause is unknown, and there is no single cure; some patients benefit from cooling the legs, others from warming them.
Treatment with levodopa and calcium channel blockers can sometimes help.... restless legs
Causes The simplest cause of vertigo is some mechanical disturbance of the body affecting the ?uid in the internal ear; such as that produced by moving in a swing with the eyes shut, the motion of a boat causing sea-sickness, or a sudden fall. (See also MOTION (TRAVEL) SICKNESS.)
Another common positional variety is benign paroxysmal positional vertigo (BPPV) caused by sudden change in the position of the head; this causes small granular masses in the cupola of the posterior semicircular canal in the inner ear to be displaced. It may subside spontaneously within a few weeks but can recur. Sometimes altering the position of the head so as to facilitate return of the crystals to the cupola will stop the vertigo.
The cause which produces a severe and sudden giddiness is MENIÈRE’S DISEASE, a condition in which there is loss of function of the vestibular mechanism of the inner ear. An acute labyrinthitis – in?ammation of the labyrinth of the ear – may result from viral infection and produce a severe vertigo lasting 2–5 days. Because it often occurs in epidemics it is often called epidemic vertigo. Vertigo is sometimes produced by the removal of wax from the ear, or even by syringing out the ear. (See EAR, DISEASES OF.)
A severe upset in the gastrointestinal tract may cause vertigo. Refractive errors in the eyes, an attack of MIGRAINE, a mild attack of EPILEPSY, and gross diseases of the brain, such as tumours, are other causes acting more directly upon the central nervous system. Finally, giddiness may be due to some disorder of the circulation, for example, reduced blood supply to the brain produced by fainting, or by disease of the heart.
Treatment While the attack lasts, this requires the sufferer to lie down in a darkened, quiet room. SEDATIVES have most in?uence in diminishing giddiness when it is distressing. After the attack is over, the individual should be examined to establish the cause and, if necessary, to be given appropriate treatment.
Vertigo and nausea linked to Menière’s disease – or following surgery on the middle ear – can be hard to treat. HYOSCINE, ANTI HISTAMINE DRUGS and PHENOTHIAZINES – for example, prochlorperazine – are often e?ective in preventing and treating these disorders. Cinnarizine and betahistine have been marketed as e?ective drugs for Menière’s disease; for acute attacks, cyclizine or prochlorperazine given by intramuscular injection or rectally can be of value. Research in America is exploring the use of virtual-reality technology to change subjects’ visual perception of the outside world gradually during several 30-minute sessions, helping them to adjust to the abnormal sensations that occur during an attack. Early results are promising.... vertigo
spinal anaesthesia Injection of an anaesthetic into the cerebrospinal fluid in the spinal canal to block pain sensations before they reach the central nervous system. It is used mainly during surgery on the lower abdomen and legs.
(See also epidural anaesthesia.)... spina bifida
Each bud contains about 25 sensory receptor cells, with tiny taste hairs that respond to food and drink.
Taste buds on different parts of the tongue sense the 4 basic tastes: bitter, sour, salty, and sweet.
buds from stomatitis, mouth cancer, or radiotherapy to the mouth; or damage to nerves that carry taste sensations.... taste bud
Causes Vomiting is brought about by stimulation of this nervous centre, and in most cases this is e?ected through sensations derived from the stomach itself. Thus, of the drugs which cause vomiting, some act only after being absorbed into the blood and carried to the brain, although most are irritants to the mucous membrane of the stomach (see EMETICS); various diseases of the stomach, such as cancer, ulcer and food poisoning act in a similar way. Stimulation – not only of the nerves of the stomach, but also of those supplying other abdominal organs – produces vomiting; thus in obstruction of the bowels, peritonitis, gall-stone colic, renal colic, and even in some women during pregnancy, vomiting is a prominent symptom.
Severe emotional shock may cause vomiting, as may acute anxiety and unpleasant experiences such as seeing an accident, suffering severe pain or travel sickness.
Direct disturbance of the brain itself is a cause: for example, a blow on the head, a cerebral tumour, a cerebral abscess, meningitis. Nausea and vomiting are common symptoms that may arise from local disease of the gastrointestinal tract, but they are also associated with systemic illness – for example, DIABETES MELLITUS or kidney failure (see KIDNEYS, DISEASES OF) – and also with disturbances of labyrinthine function, such as motion sickness and acute labyrinthitis.
Treatment The cause of the vomiting must be sought and treatment directed towards this. Symptomatic treatment for vomiting can be dangerous since accurate diagnosis of the cause may be hindered. If antinauseant drug treatment is indicated, the choice of drug depends on the cause of the vomiting.
Granisetron and ondansetron are 5hydroxytryptamine (5HT3) antagonists valuable in the treatment of nausea and vomiting induced by cytotoxic CHEMOTHERAPY or RADIOTHERAPY and prevention and treatment of post-operative nausea and vomiting. Prochlorperazine is valuable in the treatment of severe nausea, vomiting, VERTIGO and disorders of the LABYRINTH of the EAR, although extrapyramidal symptoms may occur, particularly in children, elderly and debilitated patients.
Vomiting may occur after surgical operations and this is due to the combined effects of analgesics, anaesthetic agents and the psychological stress of operation. Various drugs can be used to prevent or stop post-operative vomiting.
Nausea and vomiting are common symptoms in pregnancy. Drugs are best avoided in this situation as they may damage the developing FETUS. Simple measures, such as the taking of food before getting up in the morning and reassurance, are often all that is necessary.... vomiting
Numbness and pins-and-needles are common abnormal sensations. The special senses can be impaired by damage to the relevant sensory apparatus (see vision, disorders of; smell; deafness; tinnitus). Other causes of abnormal sensation include peripheral nerve damage caused by diabetes mellitus, herpes zoster infection, or pressure from a tumour, and disruption of nerve pathways in the brain or spinal cord due to spinal injury, head injury, stroke, and multiple sclerosis.
Pressure on or damage to nerves can sometimes be relieved by surgery or by treatments for the cause.
In other cases, distressing abnormal sensation can be relieved only by cutting the relevant nerve fibres or by giving injections to block the transmission of signals.... sensation, abnormal
The cerebellum is essential for the maintenance of muscle tone, balance, and the synchronization of activity in groups of muscles under voluntary control, converting muscular contractions into smooth coordinated movement. It does not, however, initiate movement and plays no part in the perception of conscious sensations or in intelligence. —cerebellar adj.... cerebellum
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