Patient Resources: Stroke



What is a stroke/’brain attack’?
A stroke is the rapidly developing loss of brain function(s) due to disturbance in the blood supply to the brain.
The traditional definition of stroke, devised by the World Health Organization (WHO) in the 1970s, is a "neurological deficit of cerebrovascular cause that persists beyond 24 hours or is interrupted by death within 24 hours". This definition was supposed to reflect the reversibility of tissue damage and was devised for the purpose, with the time frame of 24 hours being chosen arbitrarily. The 24-hour limit divides stroke from transient ischemic attack, which is a related syndrome of stroke symptoms that resolve completely within 24 hours.With the availability of treatments that, when given early, can reduce stroke severity, many workers now prefer alternative terms, such as brain attack and acute ischemic cerebrovascular syndrome, that reflect the urgency of stroke symptoms and the need to act quickly.
What are the types of stroke?
Stroke can be due to lack of blood flow (ischemia) =Ischemic Stroke, caused by blockage of an artery due to a clot within, or a hemorrhage (leakage of blood from the blood vessel) = Hemorrhagic stroke.
When a blood clot or a piece of atherosclerotic plaque (cholesterol and calcium deposits on the wall of the artery) lodges in an artery of the brain, it blocks the flow of oxygen-rich blood. The clot can develop in the brain artery itself (Thrombotic stroke) or can travel with the blood flow from another site like heart or another large blood vessel (Embolic stroke).
A cerebral hemorrhage occurs when a blood vessel in the brain bursts and bleeds into the surrounding brain tissue.

About 85% of strokes are caused by ischemia and the remainder by hemorrhage.
What are the features of stroke?
A stroke is a medical emergency and can cause permanent neurological damage, complications, and death. Stroke symptoms typically start suddenly within minutes and in most cases do not progress further. The symptoms depend on the area of the brain affected. The most common symptom is weakness (paralysis) of one side of the body. There may be partial or complete loss of voluntary movement of and/or sensation in a leg and/or arm. A stroke can result in speech problems and weakens muscles of the face, which can cause drooling. Numbness or tingling is very common. A stroke can cause difficulty inbreathing and even unconsciousness. The more extensive the area of brain affected, the more functions that are likely to be lost.


Silent stroke: A silent stroke is a stroke that does not have any outward symptoms, and the patients are typically unaware they have suffered a stroke. Despite not causing identifiable symptoms, a silent stroke still causes damage to the brain, and places the patient at increased risk for both transient ischemic attack and major stroke in the future. Conversely, those who have suffered a major stroke are at risk of having silent strokes. Silent strokes are estimated to occur at five times the rate of symptomatic strokes.
Some forms of stroke can cause additional symptoms. For example, in intracranial hemorrhage, the affected area may compress other structures. Most forms of stroke are not associated with headache, apart from subarachnoid hemorrhage and cerebral venous thrombosis and occasionally intracerebral hemorrhage.
How is a stroke diagnosed?
Anyone suspected of having a stroke should be taken to a medical facility immediately for evaluation and treatment. Other causes that can mimic a stroke include brain tumors, subdural hematomas (collections of blood between the brain and the skull), or brains abscess (a collection of pus in the brain caused by bacteria or a fungus). Viral encephalitis can cause symptoms similar to those of a stroke as can an overdose of certain medications. Following tests are generally carried out in the assessment of a stroke.
Routine testing stroke patients:
  • Full blood count
  • Blood glucose
  • Blood urea, electrolytes
  • Chest radiograph
  • ECG
  • CT scan
  • Blood coagulation profile
Urgent CT scan of the head is mandatory in all acute stroke patients. It is easily available, very fast and serves the purpose in most patients. In some cases the physician may ask the patient to undergo and MRI scans as well.

   
Risk factors for stroke:
  • Arterial Hypertension ( high BP)
  • Cigarette smoking
  • Diabetes mellitus
  • Hyperlipedaemia
  • Polycythaemia
  • Thrombocythaemia
  • High alcohol intake
  • Positive family history
  • Oral contraceptives
  • Trauma
Stroke without an obvious explanation is termed "cryptogenic" (of unknown origin); this constitutes 30-40% of all ischemic strokes.
Additional tests in younger patients
  • Antinuclear factor
  • Anti-bodies to double-stranded DNA
  • Anti-cardiolipin antibodies
  • Lupus anti-coagulant
  • Cholesterol
What is the treatment for stroke?
Early assessment of stroke is essential in order to start the appropriate therapy and limit, if possible any further damage due to stroke.

  • Careful nursing
    Regular turning of a patient to avoid pressure sores; skin kept dry and clean
  • Care of airway
    Oropharyngeal tube with regular suction of secretions if the patient is unconscious
  • Fluid balance
    Nasogastric feeding if patient cannot swallow; bladder catheterisation if incontinent
  • Physiotherapy
    Start immediately to prevent joint contractions; to clear chest secretions; to promote recovery of strength and coordination
  • Speech and occupational therapy
    Start once acute stage over to assess functional problems and to encourage recovery skills
The blood sugar (glucose) in diabetics is often quite high after a stroke. Controlling the glucose level may minimize the size of a stroke. Before long, drugs that can actually dissolve blood clots may have a place in stroke treatment. Oxygen is administered when necessary. New medications that can help oxygen-starved brain cells survive, while circulation is re-established, are being developed.
When a patient is no the mend after a stroke, the health care staff turns toward maximizing the patient's functional abilities. The rehabilitation process can involve speech therapy to relearn talking and swallowing, occupational therapy for regaining dexterity of the arms and hands, physical therapy for improving strength and walking, and family education to orient them towards caring for their loved one at home. The goal is for the patient to resume as many if not all of their pre-stroke activities and functions.
Active treatment of stroke:
Depending upon the type of stroke and the clinical evaluation findings, the physician decides the further active treatment plan.
  1. Ischemic stroke: Clot busting medications can be given intravenously to dissolve the clot in the arteries so that blood flow is restored. Prior to it the physician evaluates the patient for suitability for ‘thrombolysis’. In certain patients, intraarterial therapy (done by interventional neuroradiologists) can be done to dissolve or retrieve the clot out of the blood vessel. Some patients may not be found suitable for either therapy however and they will be put on blood thinning drugs( antiplatelets or anticoagulants)
  2. Hemorrhagic stroke: Depending upon the type of hemorrhage the physician will decide the further active treatment e.g for subarachnoid hemorrhage; a DSA is done which usually shows an aneurysm and can be treated by interventional neuroradiologists by endovascular coiling. If there is a large intraparenchymal hemorrhage then open surgery to remove the clot and relieve pressure on the normal areas of the brain can be undertaken (craniotomy) by a neurosurgeon.
A: DSA showing an aneurysm of an artery called anterior communicating artery, a very common site of involvement
B: Endovascular coiling has been done. DSA after coiling shows complete packing of the aneurysm thus preventing chances of re-bleeding

How can stroke be prevented?

One way to prevent a stroke is to notice a transient ischemic attack (TIA) - or mini stroke - that provides symptoms similar to stroke. Knowing the symptoms of stroke can lead to earlier treatment and better recovery.

Much of stroke prevention is based on living a healthy lifestyle. This includes:
  • Knowing and controlling blood pressure
  • Finding out if you have atrial fibrillation
  • Not smoking
  • Lowering cholesterol, sodium, and fat intake
  • Following a healthy diet
  • Drinking alcohol only in moderation
  • Treating diabetes properly
  • Exercising regularly. Moderate aerobic fitness can reduce stroke risk,
  • Managing stress
  • Not using drugs
  • Taking preventive medications such as anti-platelet and anticoagulant drugs to prevent blood clots
  • Cholesterol lowering drugs can prevent stroke recurrence
  • Secondary prevention of stroke: means ‘to prevent re happening of stroke after the patient has recovered from the present episode’. The patient will undergo some form of angiography (CTA, MRA or DSA) to have a look at the blood vessels If any narrowing is found then ‘angioplasty’ and ‘stenting’ may be offered by the interventional neuroradiologist.




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