Athetosis Health Dictionary

Abnormal movements of the muscles resulting from disorder of the brain. Movements are uncoordinated and involuntary and occur in facial as well as limb muscles. They include athetosis (writhing movements), CHOREA (jerking movements predominate), choreoathetosis (a combined type), myoclonus (spasms), tics and tremors.... dyskinesia

The term used to describe a group of conditions characterised by varying degrees of paralysis and originating in infancy or early childhood. In some 80 per cent of cases this takes the form of spastic paralysis (muscle sti?ness), hence the now obsolete lay description of sufferers as ‘spastics’. The incidence is believed to be around 2 or 2·5 per 1,000 of the childhood community. In the majority of cases the abnormality dates from well before birth: among the factors are some genetic malformation of the brain, a congenital defect of the brain, or some adverse e?ect on the fetal brain as by infection during pregnancy. Among the factors during birth that may be responsible is prolonged lack of oxygen such as can occur during a di?cult labour; this may be the cause in up to 15 per cent of cases. In some 10–15 per cent of cases the condition is acquired after birth, when it may be due to KERNICTERUS, infection of the brain, cerebral thrombosis or embolism, or trauma. Acute illness in infancy, such as meningitis, may result in cerebral palsy.

The disease manifests itself in many ways. It may not be ?nally diagnosed and characterised until the infant is two years old, but may be apparent much earlier – even soon after birth. The child may be spastic or ?accid, or the slow, writhing involuntary movements known as athetosis may be the predominant feature. These involuntary movements often disappear during sleep and may be controlled, or even abolished, in some cases by training the child to relax. The paralysis varies tremendously. It may involve the limbs on one side of the body (hemiplegia), both lower limbs (paraplegia), or all four limbs (DIPLEGIA and QUADRIPLEGIA). Learning disability (with an IQ under 70) is present in around 75 per cent of all children but children with diplegia or athetoid symptoms may have normal or even high intelligence. Associated problems may include hearing or visual disability, behavioural problems and epilepsy.

The outlook for life is good, only the more severely affected cases dying in infancy. Although there is no cure, much can be done to help these disabled children, particularly if the condition is detected at an early stage. Assistance is available from NHS developmental and assessment clinics, supervised by community paediatricians and involving a team approach from experts in education, physiotherapy, occupational therapy and speech training. In this way many of these handicapped children reach adulthood able to lead near-normal lives. Much help in dealing with these children can be obtained from SCOPE (formerly the Spastics Society), and Advice Service Capability Scotland (ASCS).... cerebral palsy

Bradykinesia refers to the slow, writhing movements of the body and limbs that may occur in various brain disorders (see ATHETOSIS).... bradykinesia

Chorea, or St Vitus’s dance, is the occurrence of short, purposeless involuntary movements of the face, head, hands and feet. Movements are sudden, but the affected person may hold the new posture for several seconds. Chorea is often accompanied by ATHETOSIS, when it is termed choreoathetosis. Choreic symptoms are often due to disease of the basal ganglion in the brain. The withdrawal of phenothiazines may cause the symptoms, as can the drugs used to treat PARKINSONISM. Types of chorea include HUNTINGTON’S CHOREA, an inherited disease, and SYDENHAM’S CHOREA, which is autoimmune. There is also a degenerative form – senile chorea.... chorea

Dystonia refers to a type of involuntary movement characterised by a sustained muscle contraction, frequently causing twisting and repetitive movements or abnormal postures, and caused by inappropriate instructions from the brain. It is sometimes called torsion spasm, and may be synonymous with ATHETOSIS when the extremities are involved. Often the condition is of unknown cause (idiopathic), but an inherited predisposition is increasingly recognised among some cases. Others may be associated with known pathology of the brain such as CEREBRAL PALSY or WILSON’S DISEASE.

The presentation of dystonia may be focal (usually in adults) causing blepharospasm (forceful eye closure), oromandibular dystonia (spasms of the tongue and jaw), cranial dystonia/Meige syndrome/Brueghel’s syndrome (eyes and jaw both involved), spastic or spasmodic dysphonia/laryngeal dystonia (strained or whispering speech), spasmodic dysphagia (di?culty swallowing), spasmodic torti/latero/ ante/retrocollis (rotation, sideways, forward or backward tilting of the neck), dystonic writer’s cramp or axial dystonia (spasms deviating the torso). Foot dystonia occurs almost exclusively in children and adolescents. In adults, the condition usually remains focal or involves at most an adjacent body part. In children, it may spread to become generalised. The condition has always been considered rare, but commonly is either not diagnosed or mistakenly thought to be of psychological origin. It may, in fact, be half as common as MULTIPLE SCLEROSIS (MS). Similar features can occur in some subjects treated with major tranquillising drugs, in whom a predisposition to develop dystonia may be present.

One rare form, called dopa-responsive dystonia, can be largely abolished by treatment with LEVODOPA. Particularly in paediatric practice this drug will often be tried on a child with dystonia.... dystonia

A condition in which the jerky, uncontrolled movements characteristic of chorea are combined with the slower, continuous writhing movements of athetosis.

Choreoathetosis occurs in children with cerebral palsy and as a side effect of certain drugs.... choreoathetosis

Irregular and uncontrollable flinging movements of the arm and leg on 1 side of the body, caused by disease of the basal ganglia. (See also athetosis; chorea.)... hemiballismus

Uncontrolled movements of the body. These movements occur spontaneously and may be slow and writhing (see athetosis); rapid, jerky, and random (see chorea); or predictable, stereotyped, and affecting 1 part of the body, usually the face (see tic). They may be a feature of a disease (for example, Huntington’s disease) or a side effect of certain drugs used to treat psychiatric conditions.... involuntary movements

These consist either of expanding masses (lumps or tumours), or of areas of shrinkage (atrophy) due to degeneration, or to loss of blood supply, usually from blockage of an artery.

Tumours All masses cause varying combinations of headache and vomiting – symptoms of raised pressure within the inexpansible bony box formed by the skull; general or localised epileptic ?ts; weakness of limbs or disordered speech; and varied mental changes. Tumours may be primary, arising in the brain, or secondary deposits from tumours arising in the lung, breast or other organs. Some brain tumours are benign and curable by surgery: examples include meningiomas and pituitary tumours. The symptoms depend on the size and situation of the mass. Abscesses or blood clots (see HAEMATOMA) on the surface or within the brain may resemble tumours; some are removable. Gliomas ( see GLIOMA) are primary malignant tumours arising in the glial tissue (see GLIA) which despite surgery, chemotherapy and radiotherapy usually have a bad prognosis, though some astrocytomas and oligodendronogliomas are of low-grade malignancy. A promising line of research in the US (in the animal-testing stage in 2000) suggests that the ability of stem cells from normal brain tissue to ‘home in’ on gliomal cells can be turned to advantage. The stem cells were chemically manipulated to carry a poisonous compound (5-?uorouracil) to the gliomal cells and kill them, without damaging normal cells. Around 80 per cent of the cancerous cells in the experiments were destroyed in this way.

Clinical examination and brain scanning (CT, or COMPUTED TOMOGRAPHY; magnetic resonance imaging (MRI) and functional MRI) are safe, accurate methods of demonstrating the tumour, its size, position and treatability.

Strokes When a blood vessel, usually an artery, is blocked by a clot, thrombus or embolism, the local area of the brain fed by that artery is damaged (see STROKE). The resulting infarct (softening) causes a stroke. The cells die and a patch of brain tissue shrinks. The obstruction in the blood vessel may be in a small artery in the brain, or in a larger artery in the neck. Aspirin and other anti-clotting drugs reduce recurrent attacks, and a small number of people bene?t if a narrowed neck artery is cleaned out by an operation – endarterectomy. Similar symptoms develop abruptly if a blood vessel bursts, causing a cerebral haemorrhage. The symptoms of a stroke are sudden weakness or paralysis of the arm and leg of the opposite side to the damaged area of brain (HEMIPARESIS), and sometimes loss of half of the ?eld of vision to one side (HEMIANOPIA). The speech area is in the left side of the brain controlling language in right-handed people. In 60 per cent of lefthanders the speech area is on the left side, and in 40 per cent on the right side. If the speech area is damaged, diffculties both in understanding words, and in saying them, develops (see DYSPHASIA).

Degenerations (atrophy) For reasons often unknown, various groups of nerve cells degenerate prematurely. The illness resulting is determined by which groups of nerve cells are affected. If those in the deep basal ganglia are affected, a movement disorder occurs, such as Parkinson’s disease, hereditary Huntington’s chorea, or, in children with birth defects of the brain, athetosis and dystonias. Modern drugs, such as DOPAMINE drugs in PARKINSONISM, and other treatments can improve the symptoms and reduce the disabilities of some of these diseases.

Drugs and injury Alcohol in excess, the abuse of many sedative drugs and arti?cial brain stimulants – such as cocaine, LSD and heroin (see DEPENDENCE) – can damage the brain; the effects can be reversible in early cases. Severe head injury can cause localised or di?use brain damage (see HEAD INJURY).

Cerebral palsy Damage to the brain in children can occur in the uterus during pregnancy, or can result from rare hereditary and genetic diseases, or can occur during labour and delivery. Severe neurological illness in the early months of life can also cause this condition in which sti? spastic limbs, movement disorders and speech defects are common. Some of these children are learning-disabled.

Dementias In older people a di?use loss of cells, mainly at the front of the brain, causes ALZHEIMER’S DISEASE – the main feature being loss of memory, attention and reasoned judgement (dementia). This affects about 5 per cent of the over-80s, but is not simply due to ageing processes. Most patients require routine tests and brain scanning to indicate other, treatable causes of dementia.

Response to current treatments is poor, but promising lines of treatment are under development. Like Parkinsonism, Alzheimer’s disease progresses slowly over many years. It is uncommon for these diseases to run in families. Multiple strokes can cause dementia, as can some organic disorders such as cirrhosis of the liver.

Infections in the brain are uncommon. Viruses such as measles, mumps, herpes, human immunode?ciency virus and enteroviruses may cause ENCEPHALITIS – a di?use in?ammation (see also AIDS/HIV).

Bacteria or viruses may infect the membrane covering the brain, causing MENINGITIS. Viral meningitis is normally a mild, self-limiting infection lasting only a few days; however, bacterial meningitis – caused by meningococcal groups B and C, pneumococcus, and (now rarely) haemophilus – is a life-threatening condition. Antibiotics have allowed a cure or good control of symptoms in most cases of meningitis, but early diagnosis is essential. Severe headaches, fever, vomiting and increasing sleepiness are the principal symptoms which demand urgent advice from the doctor, and usually admission to hospital. Group B meningococcus is the commonest of the bacterial infections, but Group C causes more deaths. A vaccine against the latter has been developed and has reduced the incidence of cases by 75 per cent.

If infection spreads from an unusually serious sinusitis or from a chronically infected middle ear, or from a penetrating injury of the skull, an abscess may slowly develop. Brain abscesses cause insidious drowsiness, headaches, and at a late stage, weakness of the limbs or loss of speech; a high temperature is seldom present. Early diagnosis, con?rmed by brain scanning, is followed by antibiotics and surgery in hospital, but the outcome is good in only half of affected patients.

Cerebral oedema Swelling of the brain can occur after injury, due to engorgement of blood vessels or an increase in the volume of the extravascular brain tissue due to abnormal uptake of water by the damaged grey (neurons) matter and white (nerve ?bres) matter. This latter phenomenon is called cerebral oedema and can seriously affect the functioning of the brain. It is a particularly dangerous complication following injury because sometimes an unconscious person whose brain is damaged may seem to be recovering after a few hours, only to have a major relapse. This may be the result of a slow haemorrhage from damaged blood vessels raising intracranial pressure, or because of oedema of the brain tissue in the area surrounding the injury. Such a development is potentially lethal and requires urgent specialist treatment to alleviate the rising intracranial pressure: osmotic agents (see OSMOSIS) such as mannitol or frusemide are given intravenously to remove the excess water from the brain and to lower intracranial pressure, buying time for de?nitive investigation of the cranial damage.... brain, diseases of

This is a complex part of the nervous system, extending from the cortex to the medulla in the BRAIN, from which emerge descending spinal pathways which in?uence voluntary motor activity throughout the body. Although the normal functions of the system are poorly understood, there are characteristic signs of an extrapyramidal LESION. These include disturbance of voluntary movements, notably slowness and ‘poverty’ of movement; disturbance of muscular tone, which may be increased or decreased; and involuntary movements, such as a tremor, irregular jerking movements, or slow writhing movements.

Diseases There are several diseases that result from lesions to the extrapyramidal system, of which the most common is PARKINSONISM. Others include WILSON’S DISEASE, KERNICTERUS, CHOREA and ATHETOSIS.... extrapyramidal system