A condition that occurs when a burst or clogged artery interrupts flow of blood to the brain. This deprives the brain of food and oxygen and as a result, brain cells begin to die. These dead brain cells cause loss of the functions in different parts of the body. Loss of feeling, reasoning problems, language problems, problems in vision and visual perception, speech problems, coma, difficulty swallowing, muscle weakness and paralysis can be caused by a stroke. A stroke requires prompt treatment in order to minimize the damage caused to the brain and to avoid the potential complications.
A stroke can be categorized into two types –
A mini stroke or a transient ischaemic attack (TIA) happens when there is temporary blockage in blood supply to the brain and commonly associated with it is a stroke like feeling, which lasts for a little time. This is an indication that a part of the brain is not getting sufficient blood & may result in a severe stroke in the future.
There are many signs indicating occurrence of a stroke, which is largely dependant on what part of the brain is being affected. The symptoms include –
A blood test and physical exam are performed to diagnose stroke. Sometimes imaging is also used. A CT scan or computerized tomography helps in determining whether a person has a stroke and the type of stroke he/she has. Artery structures can be viewed by performing a specialized CT scan where a dye is injected into the vein. In order to view the damaged brain tissue, MRI or magnetic resonance imaging test is performed.
Clotting in the carotid artery (a major artery that travels up the neck into the brain) can be detected by performing a carotid ultrasound. Echocardiography ultrasound is performed to produce images of the heart which help in determining whether the stroke is caused by an embolus.
Treatments for both hemorrhagic and ischemic stroke are different.
The purpose of treating ischemic stroke is to restore flow of blood in the brain. Medications are given within the first four and a half hours of the stroke to destroy the clots in blood vessels. An injection of tissue plasminogen (TPA) can also be given to a patient to improve probability of a full recovery.
The main purpose of treating a hemorrhagic stroke is to stop bleeding and decrease pressure on the brain. Clotting drugs can be prescribed instead of blood thinners. After the area has been healed and bleeding is controlled, damaged and leaky blood vessels are repaired.
The first stroke device approved by FDA is the Merci retriever. The aim of this device is to restore flow of the blood in the neurovasculature by removing thrombus in patients suffering from ischemic stroke.
The penumbra system (endovascular thromboaspiration) is the latest FDA approved device that has been primarily developed for removing clots in cases of acute ischemic stroke. In order to eliminate or reduce the clot burden, the system uses dual approaches to clot extraction through debulking and aspiration of the thrombus. Clot retrieval is then performed using a ring like device that captures the thrombus in clasps and places it in a cylinder. The thrombus is then withdrawn when flow stops. This new aspiration device (the penumbra system) has an excellent safety profile and a high rate of ‘target vessel’ recanalization.