A stroke occurs due to brain damage because of decrease in blood supply to brain because of a blockage in the blood vessel feeding the brain. Sometimes it occurs when a blood vessel bursts, leading to bleeding in the brain. Just as heart attack which occurs due to decrease in blood supply to heart, stroke is a very serious condition and is also referred to as "brain attack".
If treatment is not started early enough in a brain attack patient, brain damage may be very severe. Every minute approximately two million neurons die; therefore, time is brain and emergent measures to open the blocked artery should be undertaken. New treatments are available which can significantly reduce the damage. However, these treatments work best soon after the brain attack.
Transient ischaemic attacks (TIAs) are "mini strokes" that produce stroke like symptoms but no lasting damage. However, patients having TIAs have a strong possibility of suffering from major stroke in future.
To know more about recognizing stroke symptoms click on the following link :- Stroke Association If you suspect yourself or someone else to be having these symptoms, DONOT WAIT and go to a hospital having emergency stroke treatment facilities.
CT (Computed tomography)- this tests involve taking a series of images of the brain to detect stroke (brain attack). This test is usually the first investigation to be performed and is particularly useful to look for presence for bleeding (haemorrhagic brain attack). MRI (Magnetic resonance imaging)- This is very specialized test which uses magnetic properties of body to create very detailed images of brain as well as of blood vessels so as to diagnose brain attack.
DSA- digital subtraction angiography)- This is the most accurate in diagnosis of most of the diseases of blood vessel. A small tube (catheter) is guided from the leg blood vessel in to the blood vessel we wish to study followed by dye (contrast) injections to obtain the images. CT/MR angiography is also an option in some cases.
Doppler ultrasound: in this ultrasound method is used to image the blood vessels and the abnormalities in them.
Brain attack due to decreased blood supply (ischaemic stroke) Patients are given anti-platelet drugs, which act as "blood thinners" so as to prevent clot formation. If patient reaches early enough to a hospital with acute stroke units, they can be given thrombolytic drugs which act as clot busters and open up the blockage in the arteries so as to save as much of brain as possible. The narrowing in the arteries which have caused stroke can also be opened up by surgical or endovascular means. Brain attack due to bleeding in the brain (haemorrhagic stroke) Treatment options will depend upon the cause and size of haemorrhage. Some patients may need surgery to remove the clot, while other cases may need to be managed conservatively in ICU. Patient with bleeding due to swelling in blood vessels of brain known as "aneurysms', will need to undergo repair of these swelling because they have a high tendency to rebleed.
Carotid Artery Angioplasty/Stenting: Carotid artery is a blood vessel which supplies blood to brain and its narrowing can result in brain attack. The narrowing can be treated by opening it up with a balloon followed by placing a metal mesh scaffolding (stent) across it. This is proven to be more effective than medical treatment alone in reducing the risk. This is performed early (< 2 weeks) after a minor attack to prevent a further disabling stroke.
Intravenous/Intrarterial Thrombolysis: Brain attack caused by decreased blood supply to brain can be treated by giving drugs which can open up the blockade so as to save as much of the brain as possible. These drugs can be given by intravenous route if a patient comes to the hospital within & 5 hours of onset of brain attack. These drugs can also be precisely given with in the area of blockade by placing a catheter (a small tube) from one of the leg blood vessels in to the blocked vessel. This selective (intra-arterial) treatment can be given at least up to 6-hours after the brain attack.
New Evidence Mechanical Thrombectomy: Mechanical thrombectomy is now strongly recommended for patients in whom large arteries within the brain are blocked. To open the blocked artery, doctors thread a catheter through the groin artery to the occlusion site in the brain. The stent (wired-caged device ) opens and grabs the clot, allowing doctors to remove the stent with the trapped clot. Special suction tubes may also be used. The procedure should be done within six hours of acute stroke symptoms. In > 80% of patients, the blockage can be opened and flow in the artery be established with this treatment. Approximately 60% of patients will have good recovery and be independent at 3 months.
When blood flow to the brain stops, brain cells are deprived of oxygen and nutrients. Stroke is a medical emergency because brain cells start dying quickly and the treatment is most effective when given promptly. Although some of the cells die within few minutes, surrounding zone though hypoperfused but are receiving just enough oxygen from cerebral blood flow (CBF) to stay alive. A compromised cell can survive for several hours in a low-energy state and is referred to as "penumbra". If blood flow is restored within this narrow window of opportunity then some of these cells can be salvaged and become functional again. Blood flow to these cells can be achieved by administrating the clot-dissolving thrombolytic agent t-PA by intravenous and intra-arterial routes.
Stroke centre- is a hospital or part of a hospital that (nearly) exclusively takes care of stroke patients with specialized staff with team approach to treatment and care. Care in stroke teams (including neurologists, neurosurgeons, interventional and diagnostic neuroradiologists) or by stroke units improve the outcome in these patients significantly.
One of the disadvantages of using thrombolytic drugs is that there is risk of bleeding. Another issue is that in large vessel blockage thrombolytic drug is not effective. These drugs cannot be used in many situation such as recent surgery. To avoid these problems, mechanical means can be used to takeout the clot and open up the blocked brain blood vessel. One such device is retriever. To open the blocked artery, doctors thread a catheter through the groin artery to the occlusion site in the brain. The stent (wired-caged device ) opens and grabs the clot, allowing doctors to remove the stent with the trapped clot.
Patient was admitted with acute stroke of 1/2 hours duration with Left hemiparesis and inability to speak. CT scan revealed a subtle hypodensity in the right basal ganglia . CT perfusion revealed a large area of penumbra. revealed left M1 MCA occlusion. Solitaire 4 x 40 mm stent was deployed across the occlusion and successful retrieval of the clot was done. Complete reperfusion was achieved in the occluded territory. CT scan next day revealed a small infarct and patient made a near complete recovery prior to discharge. Patient slowly recovered and started walking with support.