Stroke is rapidly developing cerebral dysfunction due to vascular cause with symptoms
lasting 24 hours or longer, or leading to death. The usual symptoms of stroke are
loss of consciousness and paralysis of muscles. Events lasting for less than 24
hours are termed as transient ischaemic attack (TIA). The characteristics of the
mode of onset, together with specific neurological symptoms and signs, depend on
the nature of vascular injury and site of injury. Stroke ranks first in frequency
as well as in urgency among neurological disorders, accounting for more than half
of all neurological diseases in old age. It is one of the first three causes of
death and the leading cause of disability in later life. Half of the patients with
stroke succumb to the disease in the first year and only one-third of the survivors
make good recovery.
Stroke is a syndrome resulting from a range of heterogeneous conditions that affect
the cerebral vasculature and blood flow. Strokes can be either occlusive or haemorrhagic.
Occlusive or ischaemic strokes account for 70 to 80% of all strokes and can be due
to thrombosis (clot formation at the site of obstruction) or embolism (occlusion
due to a dislodged clot from elsewhere). Thrombotic strokes are the commonest of
all varieties of stroke resulting from the narrowing of blood vessels of the brain
due to high blood cholesterol (atherosclerosis). Embolic strokes usually occurs
in presence of heart disease. Haemorrhagic strokes account for 20 to 30% all strokes
and can be due to the rupture of blood vessels inside the brain. Risk factors for
stroke
High blood pressure is the single most important risk factor for stroke. Other risk
factors for stroke include: increasing age, family history, high cholesterol, overweight,
smoking, lack of exercise, heart disease and diabetes.
Diagnosis and management
The diagnosis of stroke is always clinical. Investigations are required to confirm
the pathology and aetiology of stroke, to detect treatable cardiovascular risk factors
and identify treatable complications of stroke, for which baseline investigations
of blood, ECG and chest X-ray are useful. Imaging investigations such as CT scan
and MRI scan are sensitive investigations for the diagnosis of the aetiology of
stroke. Carotid ultrasound Doppler studies are very useful in detecting carotid
atherosclerosis in patients with TIA.
The management of stroke involves: medical intervention to minimize impairment;
prevention and treatment of acute complications; rehabilitation to minimize disability;
and adaptation to minimize handicaps. Prevention of stroke requires modification
of risk factors: hypertension, smoking, cholesterol and drug therapy (which prevent
clotting) in the presence of a history of TIA.
Rehabilitation
The patient as well as the family requires support in terms of education, training
and counselling. Community and domicilliary rehabilitative services are essential
for stroke patients living in communities. The basic principles of stroke rehabilitation
are detection of the impairment and handicaps, and maximization of independence
and minimization of dependency. A holistic approach taking into account the physical
and mental state of the patient is required to achieve the best results.