Stroke is a worldwide health problem. It makes an important contribution to morbidity, mortality and disability in developed as well as developing countries. Cerebral thrombosis is usually the most frequent form of stroke encountered in clinical studies, followed by haemorrhage. Subarachnoid haemorrhage and cerebral embolism come next as regards both mortality and morbidity.
The term stroke (syn: apoplexy) is applied to the acute severe manifestation of cerebrovascular disease. It causes both physical and mental crippling. WHO defined stroke as rapidly developed clinical signs of focal disturbance of cerebral function lasting more than 24 hours or leading to death with no apparent cause other than a vascular origin. The 24 hours threshold in the definition excludes transient ischaemic attacks (TIA).
The disturbance of cerebral function is caused by three morphological abnormalities –
- Rupture of the arteries
Dysfunction of the brain (neurological deficit) manifests itself by various neurological signs and symptoms that are related to the extent and site of the area involved and to the underlying causes. These include-
- Multiple paralyses
- Speech disturbances
- Nerve paresis
- Sensory impairment
Out of the above, hemiplegia constitutes the main somato-neurological disorder in about 90 per cent of patients.
Stroke includes a number of syndromes with differing etiologies, epidemiology, prognosis and treatment which are listed in the WHO’s International Classification of Diseases:
- Subarachnoid haemorrhage – haemorrhage into the subarachnoid space is most commonly caused by rupture of aneurysms and rarely rupture of a vascular malformation.
- Cerebral haemorrhage
- Cerebral thrombosis or embolism
- Occlusion of pre-cerebral arteries
- Transient cerebral ischaemia of more than 24 hours
- Ill-defined cardiovascular disease (the underlying pathology in the brain is not determined).
Epidemiological studies reveal that stroke does not occur at random and there are factors which precede stroke:
Hypertension- this is considered the main risk factor for cerebral thrombosis as well as cerebral haemorrhage.
Additional factors contributing to risk are-
- Cardiac abnormalities: left ventricular hypertrophy, cardiac dilatation.
- Elevated blood lipids
- Glucose intolerance
- Blood clotting and viscosity
- Oral contraceptives
Transient ischemic attacks
One phenomenon that has received increasing attention is the occurrence of TIA in a fair proportion cases. These are episodes of focal, reversible, neurological deficit of sudden onset and of less than 24 hours duration. They show a tendency to recurrence. They are due to microemboli and are a warning sign of stroke.
Age: A stroke can occur at any age. Usually, incidence rates rise with age. In developed countries, over 80% of all stroke deaths occur in persons over 65 years. In India about one-fifth of incidents of stroke occur below the age of 40, this is attributed to our young population and shorter life expectancy (about 55 years).
Sex: the incidence rates are higher in males than females at 40 ages.
Personal history: the WHO study showed that nearly two-quarters of all registered stroke patients had associated diseases, mostly in the cardiovascular system or diabetes. This exports the view that in most cases stroke is merely an incident in a slowly progressive course of generalised vascular diseases.
Clinical symptoms of stoke
- Face drooping
- Arm weakness
- Speech difficulty
- Vision loss or multiple vision
- Atrial fibrillation
- Heart attack
- Injury to blood vessels in the neck
- Blood clotting
Psychological impacts of stroke
Patients suffering from two of the most common psychological problems after a stroke:
- Depression: – patient may experience intense bouts of crying, feel low or hopeless and refuse social involvement.
- Anxiety:- generally patients undergo feelings of fear and anxiety i.e. anxiety attacks, feelings of anger, frustration and bewilderment.
For such patients, medicines and psychological therapies such as counselling or cognitive behavioural therapy (CBT) may overcome to psychological impacts of stroke.
Cognitive impacts of stroke
Cognitive functions of the brain may be disrupted by a stroke which are:
- Logical aptitude- the ability to plan, solve a problem
- Praxis – the ability to carry out skilled physical activities or professional work
- Social awareness
- Vascular dementia
Stroke control programme
The aim of a stroke control programme is to apply at the community level effective measures for the prevention of stroke. The first priority goes to control arterial hypertension which is a major cause of stroke.
As transient ischaemic attacks (TIA) may be one of the earliest manifestations of stroke, their early detection and treatment are important for the prevention of stroke.
Control of diabetes, elimination of smoking, and prevention and management of other risk factors at the population level are new approaches.
Treatment for acute stroke is largely the control of complications. Facilities for the long term follow up of patients are essential. The education and training of health personnel and of the public form an integral part of the programme. For any such programme, reliable knowledge of the extent of the problem in the community concerned is essential.