Concussion of the brain Health Dictionary

The brain and spinal cord together form the central nervous sytem (CNS). Twelve cranial nerves leave each side of the brain (see NERVES, below) and 31 spinal nerves from each side of the cord: together these nerves form the peripheral nervous system. Complex chains of nerves lying within the chest and abdomen, and acting largely independently of the peripheral system, though linked with it, comprise the AUTONOMIC NERVOUS SYSTEM and govern the activities of the VISCERA.

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

Loss of brain function with unconsciousness. Cause: head injury or violent spinal jarring as when falling on the base of the spine.

Symptoms. Sudden drawing-up of knees, nausea, vomiting, pallor, shallow breathing, prostration, weak heart beat, irritability, amnesia.

Treatment. Bed rest. Protection of eyes against light. Admission to hospital in case of deep brain damage. Quietness. Tranquillisers, sedatives and alcohol aggravate symptoms. If patient can swallow, alternatives as follows:–

Teas. St John’s Wort (concussion of the spine). Skullcap (to ease headache). Ginkgo (cerebral damage). Powders. Formula. Combine, St John’s Wort 3; Skullcap 2; Oats 2; Trace of Cayenne. Dose: 750mg (three 00 capsules or half a teaspoon) two-hourly.

Tinctures. Formula as above, but with few drops Tincture Capsicum in place of Cayenne powder: 1-2 teaspoons in water hourly.

Tincture Arnica. (European practise) 2-5 drops in hot water usually sufficient to hasten recovery.

Topical. Distilled Extract Witch Hazel saturated pad over eyes and to wipe forehead.

Supplements. Vitamin B-complex. B6, C. ... concussion

A functional, semi-permeable membrane separating the brain and cerebrospinal ?uid from the blood. It allows small and lipid-soluble molecules to pass freely but is impermeable to large or ionised molecules and cells.... blood brain barrier

The irreversible cessation of all functions of the brain, including the brainstem. (See also death.)... brain death

A stalk of nerve tissue that forms the lowest part of the brain and links with the spinal cord. The brainstem acts partly as a highway for messages travelling between other parts of the brain and spinal cord. It also connects with 10 of the 12 pairs of cranial nerves (which emerge directly from the underside of the brain) and controls basic functions such as breathing, vomiting, and eye reflexes. Brainstem activities are below the level of consciousness, and they operate mainly on an automatic basis.

The brainstem is composed of 3 main parts: the midbrain, pons, and medulla. The midbrain contains the nuclei (nervecell centres) of the 3rd and 4th cranial nerves. It also contains cell groups involved in smooth coordination of limb movements. The pons contains nerve fibres that connect with the cerebellum. It also houses the nuclei for the 5th–8th cranial nerves. The medulla contains the nuclei of the 9th–12th cranial nerves. It also contains the “vital centres” (groups of nerve cells that regulate the heartbeat, breathing, blood pressure, and digestion (information on which is relayed via the 10th cranial nerve (see vagus nerve). Nerve-cell groups in the brainstem, known collectively as the reticular formation, alert the higher brain centres to sensory stimuli that may require a conscious response. Our sleep/wake cycle is controlled by the reticular formation.

The brainstem is susceptible to the same disorders that afflict the rest of the central nervous system (see brain, disorders of). Damage to the medulla’s vital centres is rapidly fatal; damage to the reticular formation may cause coma. Damage to specific cranial nerve nuclei can sometimes lead to specific effects. For example, damage to the 7th cranial nerve (the facial nerve) leads to facial palsy. Degeneration of the substantia nigra in the midbrain is thought to be a cause of Parkinson’s disease.... brainstem

An abnormal growth in or on the brain. Tumours may be primary growths arising directly from tissues within the skull or metastases (secondary growths) that have spread from tumours elsewhere in the body. The cause of primary brain tumours is not known. About 60 per cent are gliomas (frequently cancerous), which arise from the brain tissue. Other primary tumours include meningiomas, acoustic neuromas, and pituitary tumours. Most of these tumours are noncancerous, but their size can cause local damage. Certain types of primary brain tumour mainly affect children. These include 2 types of glioma called medulloblastoma and cerebellar astrocytoma. Primary brain tumours virtually never spread (metastasize) outside the central nervous system.

Symptoms include muscle weakness, loss of vision, or other sensory disturbances, speech difficulties, and epileptic seizures. Increased pressure within the skull can cause headache, visual disturbances, vomiting, and impaired mental functioning. Hydrocephalus may occur.

When possible, primary tumours are removed by surgery after opening the skull (see craniotomy).

In cases where a tumour cannot be completely removed, as much as possible of it will be cut away to relieve pressure.

For primary and secondary tumours, radiotherapy or anticancer drugs may also be given.

Corticosteroid drugs are often prescribed temporarily to reduce the size of a tumour and associated brain swelling.... brain tumour

Fixed dilated pupils of the eyes

Absent CORNEAL REFLEX

Absent VESTIBULO-OCULAR REFLEX

No cranial motor response to somatic (physical) stimulation

Absent gag and cough re?exes

No respiratory e?ort in response to APNOEA despite adequate concentrations of CARBON DIOXIDE in the arterial blood.... b nosed. the test for brain-stem death are:

Brahmi Tea isbest known in Indian Ayurvedic medicine for its role against motor and nerve disorders. It possesses a pungent and bitter flavor, being a tonic, a mild sedative and a diuretic. Brahmi Tea description Brahmi is a perennial creeping herb, commonly found in India, Nepal, Sri Lanka, China, Vietnam and in the southern parts of the United States. It grows on wetlands and muddy shores. Brahmi is medicinally and culinary used. It is known as “food for the brain”, brahmi being used since the 6^th century in Ayurvedic medicine as a cognitive enhancer. In India, the herb is still used by students and schoolchildren to help their brain functions. Brahmi tea is the resulting beverage from brewing the abovementioned plant. Brahmi Tea brewing Brahmi tea can be made by immersing ½ teaspoon of dried brahmi herbs into one cup of boiling water. Let it soak and steep it for about 5 minutes. Drink it slowly. Brahmi Tea benefits Brahmi tea has proven its efficiency in:

• improving the memory and enhancing mental functions, agility and alertness (It is helpful in retention of new information)
• calming the mind and promoting relaxation
• improving motor learning ability
• promoting greater concentration and focus
• treating asthma
• treating epilepsy
• treating indigestion

Brahmi Tea side effects High doses of Brahmi tea may causeheadaches, nausea, dizziness and extreme drowsiness. Pregnant and nursing women should not intake this beverage. Brahmi tea is a medicinal beverage successfully used to enhance the memory processes and to promote relaxation. It is also efficient in dealing with indigestion, but not only.... brahmi tea or food for the brain

Cerebral hyperemia. See Poe, Edgar Allen... brain fever

Most blows to the head cause no loss of consciousness and no brain injury. If someone is knocked out for a minute or two, there has been a brief disturbance of the brain cells (concussion); usually there are no after-effects. Most patients so affected leave hospital within 1–3 days, have no organic signs, and recover and return quickly to work without further complaints.

Severe head injuries cause unconsciousness for hours or many days, followed by loss of memory before and after that period of unconsciousness. The skull may be fractured; there may be ?ts in the ?rst week; and there may develop a blood clot in the brain (intracerebral haematoma) or within the membranes covering the brain (extradural and subdural haematomata). These clots compress the brain, and the pressure inside the skull – intracranial pressure – rises with urgent, life-threatening consequences. They are identi?ed by neurologists and neurosurgeons, con?rmed by brain scans (see COMPUTED TOMOGRAPHY; MRI), and require urgent surgical removal. Recovery may be complete, or in very severe cases can be marred by physical disabilities, EPILEPSY, and by changes in intelligence, rational judgement and behaviour. Symptoms generally improve in the ?rst two years.

A minority of those with minor head injuries have complaints and disabilities which seem disproportionate to the injury sustained. Referred to as the post-traumatic syndrome, this is not a diagnostic entity. The complaints are headaches, forgetfulness, irritability, slowness, poor concentration, fatigue, dizziness (usually not vertigo), intolerance of alcohol, light and noise, loss of interests and initiative, DEPRESSION, anxiety, and impaired LIBIDO. Reassurance and return to light work help these symptoms to disappear, in most cases within three months. Psychological illness and unresolved compensation-claims feature in many with implacable complaints.

People who have had brain injuries, and their relatives, can obtain help and advice from Headwat and from www.neuro.pmr.vcu.edu and www.biausa.org... brain injuries

I. Olfactory, to the nose (smell).

II. Optic, to the eye (sight).

III. Oculomotor

Trochlear, to eye-muscles.

Abducent

VI. Trigeminal, to skin of face.

VII. Facial, to muscles of face.

VIII. Vestibulocochlear, to ear (hearing and balancing).

IX. Glossopharyngeal, to tongue (taste).

X. Vagus, to heart, larynx, lungs, and stomach.

XI. Spinal accessory, to muscles in neck.

XII. Hypoglossal, to muscles of tongue.... nerves twelve nerves come off the brain:

Brain damage, resulting in the irreversible loss of brain function, renders the individual incapable of life without the aid of a VENTILATOR. Criteria have been developed to recognise that ‘death’ has occurred and to allow ventilation to be stopped: in the UK, these criteria require the patient to be irreversibly unconscious and unable to regain the capacity to breathe spontaneously. (See also GLASGOW COMA SCALE and PERSISTENT VEGETATIVE STATE (PVS).)

All reversible pharmacological, metabolic, endocrine and physiological causes must be excluded, and there should be no doubt that irreversible brain damage has occurred. Two senior doctors carry out diagnostic tests to con?rm that brain-stem re?exes are absent. These tests must be repeated after a suitable interval before death can be declared. Imaging techniques are not required for death to be diag-... brain-stem death

Usually associated with some loss of sensation and power in another part of the body. Taste, smell, hearing, sight and movement may be affected. The following are some of the disorders that may affect the brain. Each has a separate entry in this book.

Abscess, Alzheimer’s Disease, anoxia (oxygen starvation), coma, concussion, haemorrhage, Down’s syndrome, epilepsy, tumour, hydrocephalus (water on the brain), meningitis, multiple sclerosis, stroke (rupture of blood vessel), spina bifida, syphilis (general paralysis of the insane), sleepy sickness.

Poor circulation through the brain due to hardening of the arteries: Ginkgo, Ginseng. Ginseng stimulates the hypothalmic/pituitary axis of the brain and favourably influences its relationship with the adrenal glands.

Congestion of the brain – Cowslip (Boerwicke). Irritability of brain and spine – Hops. Oats. Inflammation of the brain (encephalitis) as in viral infection, poliomyelitis, rabies, sleepy sickness, etc: Echinacea, Passion flower, Skullcap and Lobelia. Gelsemium acts as a powerful relaxant in the hands of a practitioner: Tincture BPC (1973): dose 0.3ml.

Brain storm from hysteria, locomotor ataxia, etc – Liquid Extract Lobelia: 5ml teaspoon in water when necessary (Dr Jentzsch, 1915, Ellingwood) Supplement with Zinc, Vitamins C and E.

Blood clot, thrombosis: Yarrow. Neurasthenia: Oats, Basil, Hops.

Brain fag and jet-lag: Chamomile, Skullcap, Oats, Ginseng, Ginkgo.

Tumour may be present years before manifesting: Goldenseal.

Mental state: depression, anxiety, schizophrenia.

Tea. Formula. Skullcap, Gotu Kola and German Chamomile; equal parts. 1 heaped teaspoon to each cup water gently simmered 10 minutes. Strain. 1 cup thrice daily.

Unspecified tensive state. Formula. Tinctures. Hops 1; Passion flower 2; Valerian 2. Dose: 2 teaspoons thrice daily until diagnosis is concluded.

Unspecified torpor. Formula. Tinctures. Ginseng 1; Kola 1; Capsicum quarter. 2 teaspoons in water thrice daily until diagnosis is concluded.

Brain weakness in the elderly: Ginkgo. See: ALZHEIMER’S DISEASE.

Fluid on the brain: see HYDROCEPHALUS.

Abscess of the brain: see ABSCESS.

Brain restoratives. Black Haw, True Unicorn root, Galangal, Oats, Oatstraw, False Unicorn root, Kola, Hops. Vitamin B6. Magnesium.

Cerebral thrombosis. See entry.

Note: Cold water may help victims to survive: rapid loss of body heat protects the brain. (Child Health Department, University of Wales)

Treatment by or in liaison with general medical practitioner or hospital specialist. ... brain disorders

See brain syndrome, organic.... brain failure

Bleeding within or around the brain that is caused either by injury or by spontaneous rupture of a blood vessel. There are 4 possible types of brain haemorrhage: subdural, extradural, subarachnoid, and intracerebral. Extradural and subdural haemorrhages are usually the result of a blow to the head (see head injury). Subarachnoid and intracerebral haemorrhages usually occur spontaneously due to rupture of aneurysms or small blood vessels in the brain.... brain haemorrhage

A hypothetical condition thought to account for behavioural and other problems in children for which no physical cause is found. It may be a cause of some learning difficulties, difficulty in concentrating, impulsiveness, and hyperactivity.... minimal brain dysfunction

See brain syndrome, organic.... organic brain syndrome

A nonmedical term for hydrocephalus.... water on the brain

(ABR audiometry, brainstem evoked response audiometry, BSER) an objective test of hearing that measures the electrical activity in the auditory nerve and *brainstem following sound stimulation using repeated clicks or brief tones.... auditory brainstem response audiometry

(BNP) see natriuretic peptide.... brain natriuretic peptide

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

A collection of pus, surrounded by inflamed tissues, within the brain or on its surface. The most common sites are the frontal and temporal lobes of the cerebrum in the forebrain.

Brain abscesses may occur after a head injury, but most cases result from the spread of infection from elsewhere in the body, such as the middle ear or sinuses.

Another cause is an infection following a penetrating brain injury.

Multiple brain abscesses may occur as a result of blood-borne infection, most commonly in patients with a heart-valve infection (see endocarditis).

Symptoms include headache, drowsiness, vomiting, visual disturbances, fever, seizures, and symptoms, such as speech disturbances, that are due to local pressure.

Treatment is with antibiotic drugs and surgery.

A craniotomy may be needed to open and drain the abscess.

Untreated, brain abscesses can cause permanent damage or can be fatal.

Despite treatment, scarring can cause epilepsy in some cases.... brain abscess

Degeneration or death of nerve cells and tracts within the brain that may be localized to a particular area of the brain or diffuse. Diffuse damage most commonly results from prolonged cerebral hypoxia (which may occur in a baby during a difficult birth), cardiac arrest, respiratory arrest, or causes such as poisoning or status epilepticus (prolonged convulsions). The damage may also occur gradually due to environmental pollutants such as lead or mercury compounds (see Minamata disease) or if nerve-cell poisons build up in the brain, as in untreated phenylketonuria. Other possible causes include brain infections such as encephalitis.

Localized brain damage may occur as a result of a head injury, stroke, brain tumour, or brain abscess. At birth, a raised blood level of bilirubin (in haemolytic disease of the newborn) causes local damage to the basal ganglia deep within the brain. This leads to a condition called kernicterus. Brain damage that occurs before, during, or after birth may result in cerebral palsy.

Damage to the brain may result in disabilities such as learning difficulties or disturbances of movement or speech.

Nerve cells and tracts in the brain and spinal cord cannot repair themselves once they have been damaged, but some return of function may be possible.... brain damage

Defects and disorders of the brain, which may have one of numerous causes including infection, injury, brain tumour, or a lack of blood or oxygen (hypoxia). Because the brain is encased in the skull, any space-occupying tumour, brain abscess, or haematoma creates raised pressure, which impairs the function of the whole brain. Brain disorders that are localized in a small region may affect a specific function such as speech (see aphasia). More often, damage is more diffuse and the symptoms can be varied and numerous. Some brain disorders are congenital due to genetic or chromosomal disorders, as in Down’s syndrome. Structural defects that arise during the development of the fetus in the womb include hydrocephalus and anencephaly.

Reduced oxygen supply may occur at birth, causing cerebral palsy. Later in life, cerebral hypoxia can result from choking or from arrest of breathing and heartbeat. From middle age onwards, cerebrovascular disease is the most important cause of brain disorder. If an artery within the brain becomes blocked or ruptures, leading to haemorrhage, the result is a stroke. The brain may also be damaged by a blow to the head see head injury).

Infection within the brain (encephalitis) may be due to viral infection. Infection of the membranes surrounding the brain (meningitis) is generally due to bacterial infection. Creutzfeldt–Jakob disease is a rare, fatal brain disease associated with an infective agent called a prion which, in some cases, has been linked with (bovine spongiform encephalopathy), a disease in cattle.

Multiple sclerosis is a progressive disease of the brain and spinal cord. Degenerative brain diseases include Alzheimer’s disease and Parkinson’s disease. Emotional or behavioural disorders are generally described as psychiatric illnesses; but the distinction between neurological and psychiatric disorders is now much less clear.... brain, disorders of

Techniques that provide pictures of the brain; they are used to detect injury or disease and include X-rays, angiography, CT scanning, MRI, PET (positron emission tomography) scanning, and SPECT (single photon emission ). X-ray films can show changes in the skull caused by a fracture or, rarely, by a brain tumour or aneurysm. Angiography shows up the blood vessels in the brain, and is used to investigate subarachnoid haemorrhage, aneurysms, abnormalities of the blood vessels, and other circulatory disorders.

scanning gives images of the brain substance; it gives clear pictures of the ventricles (fluid-filled cavities) and can reveal tumours, blood clots, strokes, aneurysms, and abscesses. is especially helpful in showing tumours of the posterior fossa (back of the skull). and scanning are specialized forms of radionuclide scanning that use small amounts of radioactive material to give information about brain function as well as structure. They enable

blood flow and metabolic activity in the brain to be measured.

Ultrasound scanning is used only in premature or very young babies since ultrasound waves cannot penetrate the bones of a mature skull.... brain imaging

see auditory brainstem response audiometry.... brainstem evoked response audiometry

(DBS) a surgical treatment involving the implantation of a medical device that sends electrical impulses to specific parts of the brain. DBS in selected brain regions can provide benefits for treatment-resistant movement disorders, such as Parkinson’s disease, tremor, and *dystonia.... deep brain stimulation

(TBI) injury to the brain due to external force, such as occurs following falls, road traffic accidents, and violence. It is a major cause of death and chronic disability worldwide, especially in young males.... traumatic brain injury

Disorder of consciousness, intellect, or mental functioning that is of organic (physical), as opposed to psychiatric, origin. Causes include degenerative diseases, such as Alzheimer’s disease; infections; certain drugs; or the effects of injury, stroke, or tumour. Symptoms range from mild confusion to stupor or coma. They may also include disorientation, memory loss, hallucinations, and delusions (see delirium). In the chronic form, there is a progressive decline in intellect, memory, and behaviour (see dementia). Treatment is more likely to be successful with the acute form. In chronic cases, irreversible brain damage may already have occurred. (See also psychosis.)... brain syndrome, organic

a device similar to a *cochlear implant except that the electrode stimulates the auditory parts of the *brainstem rather than the cochlea. It is used to restore hearing of profoundly deaf people who have had damage to both auditory nerves and are hence unsuitable for cochlear implantation. It consists of an electrode that is permanently implanted on the surface of the brainstem. An external device with a microphone and an electronic processing unit pass information to the electrode using radio-frequency waves. The implant is powered by batteries in the external part of the device. It is most commonly used in patients with *neurofibromatosis type II who have had bilateral *vestibular schwannomas.... auditory brainstem implant