Stroke is one of the leading causes of death and disability in India. The incidence of stroke in India varies from 105 to 152 new cases per 100,000 population per year. Stroke is a brain attack similar to a heart attack. In a heart attack the blood vessel gets blocked, reducing the blood supply and damaging the heart. In a brain attack or stroke, the same process of blocking of blood vessels occurs, where one part of the brain does not get adequate blood supply, causing that area to become dead. This results in loss of brain function. Once damaged, the brain does not recover, causing severe disability for life. A severe heart attack may result in loss of life but if the patient survives, he/she often recovers well or may have to reduce the pace of daily activities. However, in a brain attack, patients usually do not die but are left paralysed on one side or experience speech deficit and are incapacitated for life, which in some sense is even worse. For example, if the area of the damaged brain controls speech, then speech will be lost and if the motor area is affected, then the arm or leg might not function. Risk factors and symptoms The risk factors that cause stroke are uncontrolled hypertension, diabetes, smoking, obesity, high cholesterol diet and sedentary lifestyle. These are exactly similar to the factors that contribute to heart attacks. These factors are commonly prevalent and inadequately controlled, primarily because of low public awareness. The hallmark of stroke is that it occurs suddenly. A sudden onset of impaired brain function is likely a stroke due to decreased circulation in the brain. It is very important to recognize the early warning signs as patients with acute stroke often do not seek medical assistance due to ignorance of its symptomatology. Haemorrhagic stroke- occurs when a weakened blood vessel ruptures, causing a bleed inside the brain and this damages the brain tissue. Haemorrhagic stroke is more severe than an ischemic stroke and in addition to the deficit, may be accompanied by severe headache and alteration of sensorium. If severe, the patient may go into coma or even lose his/her life. In fact, a number of patients who suddenly collapse and die may have succumbed to a major haemorrhagic stroke.
It is also important to know that a debilitating stroke may be preceded by a warning stroke – what is called a transient ischemic attack (TIA). Often called a “mini stroke”, these warning strokes are caused by temporary clots. In this condition, the patients might experience a sudden onset of transient weakness in the face, arm or speech. They experience the symptoms for 2-5 minutes, post which the blood circulation gets re-established and there is a full recovery. While most patients realize that something went wrong, they often do not seek medical attention as they feel that they are now normal. However, these TIAs are a prelude to a major debilitating stroke and must not be ignored. Treatment at this stage can prevent a lifetime of disability. Once the symptoms of stroke are recognized, the patient must be rushed to a tertiary stroke centre. Time is of essence as the sooner the patient reaches the hospital and the circulation is re-established, the better the chances of preventing major brain damage. Every minute lost results in the death of 1.9 million neurons (the cells of the brain). The tertiary stroke centre is geared for the emergency management of the stroke with a dedicated stroke team. Immediate specialized brain imaging, including angiography and perfusion studies is done to decide the type of stroke and the likelihood of benefit from advanced therapy. The treatment for ischemic stroke is thrombolysis or usage of clot busters, which dissolve the clot inside the vessel and re-establish the circulation. However, for this therapy to be effective it must be instituted within 4 hours of onset of stroke. If the patient comes after this period then mechanical thrombectomy is advisable where the clot is removed, using a stent like device. Specialized miniature wires are passed into the blood vessels from the groin, guided up in the blood stream to the brain till the site of the clot and using specialized retrievers, the clot is taken out, thus re-establishing the circulation. While thrombolysis has a time window of 4 hours, mechanical thrombectomy has a window of 24 hours due to advanced technology. Following these interventions, the circulation is established and the patient’s weakness and speech difficulty improve dramatically – often on the treatment table itself. Post the time window of 24 hours, reversing the patient’s deficit may not be possible, resulting in life-long damage. Haemorrhagic strokes may need emergency surgical evacuation of the blood clot to save life. One must remember the dictum – TIME IS BRAIN for a disability free recovery from stroke.
