Diseases of the brain
Apoplexy
(Cerebral Stroke)
By the term apoplexy or stroke is meant a sudden local disturbance in the circulation of the brain without preceding injury. There are three distinct ways in which this catastrophe can occur, all of which cause similar symptoms, although they may differ in degree.
Causes
Cerebral Thrombosis
Clotting of blood in the blood vessels of the brain is by far the commonest cause of a stroke in persons who are over the age of sixty five, with degenerated arteries of the brain. It is particularly likely to occur when a blood pressure which is habitually high is temporarily lowered so that the blood blocks an artery, thus cutting off the blood supply to the corresponding region of the brain. This results in softening of the brain and the affected part loses its function.
Cerebral Haemorrhage
Haemorrhage into the substance of the brain from a ruptured blood vessel is much less common than thrombosis but like thrombosis, it occurs in cases of high blood pressure. I results from weakness of the walls of the arteries of the brain, which may be a direct consequence of a previous thrombosis. Brights disease, alcoholism and previous syphilitic infection may also lead to weakness of the vessel walls.
Such weakened blood vessels are liable to rupture when there is any sudden increase in a blood pressure which is already raised.
Such an increase may result from sudden activity or strain such as coughing, sneezing, straining at stool or lifting heavy weights. It may also occur from over-exposure to the sun or to severe cold or to the bad air or overcrowded rooms. Not uncommonly it follows an emotional disturbance such as shock or anger, which produces a sudden rise of blood pressure. Such haemorrhage is most commonly seen in men over the age of fifty.
Cerebral Embolism
Obstruction of a blood vessel of the brain occurs when an embolus or clot of blood is brought from a distant part. When a clot of blood in the auricles of the heart becomes loose (as in cases of mitral stenosis) it may be dislodged and carried by the bloodstream until it reaches an artery too small to allow it to pass. The artery is then blocked up as in thrombosis and the blood supply to the part is cut off. When this takes place in an artery of the brain the same serious results follow as in thrombosis. Embolism is a not uncommon cause of a stroke in young persons between fifteen and thirty years of age with heart disease.
Symptoms
The actual onset of the stroke may be gradual or rapid, according to the cause. In cerebral thrombosis the onset is often gradual an the patient may notice certain premonitory symptoms such as headache, dizziness, temporary weakness in one or both limbs of one side, tingling, double vision, faltering speech and inability to remember words. These symptoms may pass away or they may become intensified during the following twenty-four hours, reaching a maximum with the appearance of the actual stroke. Cerebral thrombosis may produce extensive paralysis, without any great shock or actual loss of consciousness. The patient frequently survives.
In haemorrhage the onset is always rapid. The patient sinks to the ground and soon loses consciousness, rapidly becoming comatose with marked congestion of the face and neck. Unlike thrombosis, cerebral haemorrhage is usually fatal within a few hours or a few days from its onset. This is one of the important distinctions between apoplexy due to thrombosis and that due to haemorrhage.
In cerebral embolism the onset of the stroke is always instantaneous, instead of being gradual as in thrombosis.
Paralysis due to Apoplexy (Hemiplegia)
The commonest result of an apoplexy, whether it is due to thrombosis, haemorrhage or embolism is paralysis of one side of the body. When an entire half of the body is affected (namely the face, arm and leg) it is called hemiplegia.
In some cases of apoplexy due to embolism, however, only a single limb may be affected (monoplegia). When the damage is on the right side of the brain, the paralysis appears on the left side of the body, while damage to the left side of the brain produces paralysis on the right side of the body. When the right side of the body is paralysed, speech is often lost. When the face is involved in paralysis, the mouth is drawn to one side, the lower lip on the paralysed side hanging down so that saliva dribbles away.
In cases of apoplexy which survive (usually those due to cerebral thrombosis), a considerable degree of recovery may occur after a few weeks or months, since the actual damage to the brain is often less than the original stroke suggests. The leg usually shows the earliest and most extensive recovery. All degrees of recovery are possible and many patients survive for years without any recurrence. Some will recover almost completely, whilst others may be left with imperfect speech, a dragging leg or an arm hanging useless at the side.
Prevention
When a condition of hardening of the arteries with high blood pressure is known to be present, the only thing which can prevent the danger of a stroke is moderation in all things.
A light diet should be taken, largely vegetable, meat, fat and alcohol must be avoided. Constipation should be corrected, sexual intercourse limited and direct exposure to the sun avoided in summer.
First Aid for Stroke
At the onset of a stroke the clothes should be loosened, particularly the collar and tie. If the patient is unconscious, the head and shoulders should be turned on one side so that the tongue does not fall back and cause difficulty in breathing. No attempt should be made to feed an unconscious patient by mouth, but if consciousness returns, small liquid feeds containing glucose may be given at frequent intervals, care being taken that no food finds its way into the air passages.
Paralysis
In cases which survive the first few days, passive movements should be used daily for all the joints of the paralysed side, to prevent the suffering of the limbs.
The prevention of deformities and contractures in the paralysed limbs is of the greatest importance. A hemiplegic patient should be got on to his legs and encouraged to walk as soon as the returning power in the muscles allows the attempt to be made. For the care of the bladder and bowels, the prevention of bedsores and care of paralysed muscles.
Hydrocephalus
(Water in the brain)
Hydrocephalus is a distension of the cavities inside the brain by an accumulation of fluid within them. This distension is associated with considerable enlargement of the skull.
Causes
The disease is chiefly one of infancy and childhood. It may be congenital, when it is present from birth and is often associated with other abnormalities such as hare-lip, cleft palate, or spina bifida. In other cases it arises after birth, usually following meningitis, though it may occasionally be due to a tumour of the brain.
Symptoms
The most striking feature is the enlargement of the head caused by the pressure on the soft skull bones from within. The skull may reach an enormous size, the forehead being particularly prominent and rounded and projecting forwards. The face is triangular and contrasts markedly with the size of the forehead, which appears to overhang the eyes, displacing them downwards and giving them a sunken effect. The hair is scanty and the general nutrition of the child is poor.
The enlargement of the skull is often associated with persistent headache, vomiting, convulsions and mental backwardness.
The final outlook depends on the cause and the rate of progress of the disease. In mild cases it may be arrested and the patient may live to adult age with a fairly normal mentality.
In cases where the brain is much affected, or when epileptic convulsions are frequent, little or no improvement can be hoped for. The senses gradually become blunted, the child is deaf or blind, the intellect weakened and convulsions or paralysis may be followed by death. The condition requires to be distinguished from rickets in which the child may also have a large head.
Treatment depends on the cause of the hydrocephalus. If a tumour is present, it may be removed with good results in some cases.
Should the fluid accumulation be due to a blockage, a certain number of children benefit from a short-circuiting operation which is performed at certain hospitals. In order to distinguish the curable cases, all children with hydrocephalus should be seen early in life by an expert in these conditions.
Tumours of the brain
The brain is one of the commonest sites of new growth in the body and in young persons tumours affect the brain more frequently than any other part of the body.
The tumour may be a primary tumour of the brain substance, or it may be secondary to some primary growth elsewhere in the body. Sometimes a brain tumour is due to cysts resulting from infection by the tapeworm.
A tumour of the brain differs in two important respects from tumours occurring in other parts of the body. First, it is growing in contact with very delicate tissues which are easily destroyed. Secondly, it is growing inside a bony cavity which allows little or no room for expansion. The consequences of even small tumours are therefore very serious even in the early stages.
Symptoms
A tumour of the brain may exist for a long time without any fefinit symptoms and when these do appear they may be of great variety, depending first on the size and secondly on the situation of the tumour. Symptoms thus fall into two groups.
1. The general effects of increased pressure within the skull. As a rule, the first and most constant symptom is headache. This is rarely strictly located, though it may be referred to the nape of the neck. It is a deep, steady, dull type of headache, of moderate intensity and aggravated by coughing or straining at stool. It rarely interferes with sleep.
Vomiting occurs later and is usually of the type called cerebral vomiting, in which the sickness is not precedd by nausea. Dimness of vision is common from compression of the optic nerves. Other symptoms consist of slowing of the pulse rate, with giddiness, mental lethargy and drowsiness and general convulsions.
2. The local effects produced by the irritationor destruction of some particular part of the brain. These effects consist usually of localized fits or local areas of paralysis.
In all cases of suspected tumour of the brain, the blood should be tested for the Wassermann reaction and if this is found to be positive, the patient should be treated as for syphilis.
Treatment
Where possible, the treatment is surgical, but when removal of the growth is impossible, an operation known as decompression may be performed. In this operation, a portion of the skull is removed to relieve the pressure inside the skull and to prevent such serious complications as blindness, mental derangement and intolerable headache.
For the headache, aspirin, paracetamol and codeine may be required. For convulsions, full maintenance doses of phenobarbitone (Luminal) are prescribed.
Abscess of the brain
Causes
An abscess of the brain is always due to a spread of infection from some other part of the body. Usually the infection has its point of origin in the neighbouring tissues of the brain, the most common cause being infection in the middle ear or mastoid, while septic conditions of the nasal sinuses, carbuncle of the neck or inflammation in the scalp are other causes.
Occasionally an abscess of the brain may occur as a result of some septic condition in a distant organ of the body, the infection being carried to the brain by the bloodstream.
An abscess of the brain may vary in size, occasionally being as large as a hens egg. It causes a softening of the surrounding brain tissue.
Symptoms
In most cases the symptoms are slight and are apt to be masked by the symptoms of the preceding disease (infection of the middle ear or mastoid, empyema of the lung, etc.).
At a later stage and increase of pressure develops inside the skull, so that the symptoms are very like those of a tumour of the brain. Headache is rearely absent and may be severe, and vomiting is almost constant. Dimness of vision, drowsiness and slowing of the pulse may follow.
These symptoms are accompanied by fever which helps to distinguish the condition from a brain tumour.
Usually the abscess enlarge and unless an operation is performed, death occurs usually from rupture of the abscess which leads to general meningitis.
Treatment
Whenever the condition is suspected, the ears should be examined. Any septic affection of the ear, nasal sinuses, or scalp must be vigorously treated until it is cured.
The only treatment for a developed abscess is surgical and consists of drainage with possible later removal of the abscess capsule.
Compiled by F. I. Biswas
