Stroke is clinically defined as a neurologic syndrome characterized by acute disruption of blood flow to an area of the brain and corresponding onset of neurologic deficits related to the concerned region of brain.

Transient Ischemic Attack (TIA): TIA is also called as “mini stroke” and is defined as a neurologic deficit resolving in less than 24 hrs (generally 8-14 mins).

Stroke can be classified into two types; ischemic and hemorrhagic.

A. Ischemic strokes:

Account for 80% of all strokes.

Depending upon the cause , it can be further divided into:

Thrombotic stroke: This is a result of atherothrombosis in large/small vessels supplying blood to brain.

Embolic stroke: Occurs due to occlusion caused by an embolus. The embolus may arise either from an artery or may be cardiogenic. A number of embolic strokes are a complication of blood pooling in the atria especially in people having arrhythmias like atrial fibrillation (AF). In addition, clots may originate from the left ventricle after a recent myocardial infarction (MI), or in cases of prosthetic valves, valvular disease, and dilated cardiomyopathy.

Depending on the location , ischemic strokes can be further divided into:

Lacunar Infarction: Lacunes represent up to one third of all ischemic strokes. Lesions mainly involve the deep perforating arteries of the basal ganglia, the brainstem, and less often the deep vessels of the centrum semiovale.

Territorial Infarction: Approximately two third of all ischemic strokes represent arterial branch or stem occlusions in the territory of the carotid and vertebrobasilar system.

Distal Field Infarction (Watershed infarction): Hemodynamic infarcts straddling the border zone between two or three adjacent arterial territories represent only a small percentage of all ischemic strokes.

B. Hemorrhagic strokes:

Account for 20% of all strokes and is a result of excessive bleeding. It can be divided into two categories based on the underlying cause:

Intracerebral hemorrhage (intraparenchymal hemorrhage): Bleeding within the brain due to rupture of small, deep penetrating blood vessels. This occurs mainly due to hypertension.

Subarachnoid hemorrhage (SAH): Characterized by bleeding around the brain; commonest cause of spontaneous SAH is a ruptured saccular aneurysm (usually rupture of a berry aneurysm or arteriovenous malformation). Head injury may be responsible for SAH. However some cases are idiopathic in nature.

• Age

• Heredity

• Male gender

• Race (black/Hispanic > white)

Modifiable

• TIA

• Hypertension

• Diabetes

• Established cardiovascular disease (MI, angina, atrial fibrillation, congestive heart failure, left ventricular hypertrophy, peripheral arterial disease)

• Hyperlipidemia

• Hyperhomocysteinemia

• Smoking

• Oral contraceptives (estrogen > 50 mcg)

• Hormone replacement therapy in postmenopausal women

• Obesity

• Sedentary lifestyle

• Alcohol intake

• Drug abuse (e.g. amphetamine, Cocaine use)

• Deficiency of proteins C, S, antithrombin III, prothrombin mutation, factor leiden mutation.

Onset of stroke symptoms varies as per type of stroke.

• Thrombotic stroke develops gradually

• Embolic stroke hits suddenly

• Hemorrhagic stroke hits suddenly and continues to worsen

Commonly observed symptoms which generally occur suddenly include:

• Numbness/weakness on one side of the body

• Dizziness

• Confusion

• Loss of balance/coordination

• Nausea/vomiting

• Seizure (very rare)

• Severe headache

• Altered sensorium (consciousness)

• Movement disorder/speech disorder/blindness (depending on the area of brain affected)

• Deviation of mouth

Additional symptoms for SAH include

• Photophobia

• Painful or stiff neck

However people may experience ‘silent strokes' with no symptoms.

A silent stroke is a stroke, which causes brain damage, but does not exhibit classic symptoms of stroke such as vision changes, speech problems, and paralysis or weakness in one side. Because they do not exhibit symptoms, silent strokes are detected only when a patient undergoes a brain imaging.

• Physical examination for carotid bruits which is an indication of carotid atherosclerosis.

• Cranial CT scan: CT scanning provides more detailed information on head injuries, brain tumors and other brain diseases than do regular radiographs. The CT scan helps to differentiate between ischemic and hemorrhagic strokes.

• Magnetic resonance imaging (MRI) should be considered if CT scan is normal and the diagnosis of stroke is in doubt.

• Magnetic resonance angiography (MRA): is another increasingly used noninvasive diagnostic test to assess the degree of blockage in carotid arteries.

• Doppler ultrasonography: For assessing atherosclerosis in carotid artery.

• ECG/ Echocardiography: To identify any cardiac problem that may have led to the stroke.

• Exclusion of conditions mimicking stroke (hypoglycemia, migraine, seizure).

• Hematologic profile may help to determine coagulopathies.

• BP management: Should be kept within higher normal limits since low BP could precipitate perfusion failure. Markedly elevated BP (> 200/110 mmHg) should be managed with nitroglycerin, clonidine, labetalol, and sodium nitroprusside. More aggressive approach can be taken if thrombolytic therapy is instituted

• Blood glucose management: Should be kept within physiological levels using oral or IV glucose (in case of hypoglycemia)/insulin (in case of hyperglycemia)

• Elevated body temperature management: Antipyretics if needed should be initiated immediately.

• Use of pentoxifylline (a hemorrheological agent) in the treatment of acute ischemic stroke is controversial due to lack of adequate evidence.

This segment includes procedures like:

• Intra-arterial thrombolysis: It includes delivery of thrombolytic to the site of clot with the help of a microcatheter. Intra-arterial thrombolysis provides an effective option to thrombolytics beyond the 3hr time window, it is an effective option for selected patients with major stroke of < 6 hrs.

• Balloon angioplasty with or without stenting: Percutaneous transluminal angioplasty and intravascular stenting of affected arteries in acute stroke patients represents a promising but currently experimental approach.

Recent studies indicate that surgery is beneficial when done in low-risk settings.

• Carotid Endarterectomy : Carotid endarterectomy represents an optimal therapy for symptomatic carotid stenosis of 70% to 90% (in the non-acute phase). It is a surgical process for removal of blockage from the carotid arteries. Best results are seen in patients who have recovered from an acute event, are medically stable and do not have severe residual neurological disability.

• Decompressive Surgery (Decompressive Craniectomy): This is an effective option in case of large hemispheric strokes and edema. It includes duraplasty of the infarcted brain tissue, reduction of intracranial pressure, and increased perfusion in peri-infarct areas at risk.

• External Ventricular Drainage: In selective cases may help to reduce intracranial tension.

• The size and location of hematoma determine the prognosis of hemorrhage.

• Both hypo- and hypertension associated with acute hemorrhage should be treated cautiously to avoid excessive or precipitous blood pressure changes.

• Adequate hydration is necessary since patients with a decreased blood volume are especially prone to brain ischemia.

• Calcium channel blocker , nimodipine (60 mg PO every 4 hrs), has been reported to be modestly beneficial in case of vasospasm.

• Emergent ventricular drainage by a neurosurgeon may be necessary.

• Surgical intervention may occasionally be life saving. Surgery in patients in good neurological condition (i.e. no other complication affecting the nervous system) would be the treatment of choice, if the site is surgically easy to get to and no other complications are present.

Summary of guidelines for the Care of Patients with a Transient Ischemic Attack

Patients who have suffered a stroke remain at an increased risk of a further stroke. Annual risk of recurrence is 4.5-7%. Patients with TIA and stroke also have an increased risk of myocardial infarction and other vascular events. The risk of stroke is highest early after stroke or TIA. Therefore high priority should be given to secondary prevention.

• Persistent hypertension (> 1 month) should be treated to achieve a BP goal of < 140/85 mmHg.

• All patients with ischemic stroke who are not on anticoagulation should take an antiplatelet agent, i.e. aspirin (75-325 mg daily), or clopidogrel (75 mg). A fixed dose combination of clopidogrel and aspirin may also be used.

• Anticoagulation with warfarin (target INR 2 to 3) should be considered in every patient with atrial fibrillation (valvular/non-valvular) unless contraindicated as well as in patients with mitral valve disease, prosthetic heart valves, or within 3 months of myocardial infarction.

• Therapy with a statin should be considered for all patients with a history of ischemic heart disease and a total cholesterol > 200 mg/dl and LDL cholesterol level > 100 mg/dl following stroke.

• Diabetes should be well controlled with a fasting blood glucose goal of <126 mg/dl.

• All patients should be assessed for other vascular risk factors and be treated or advised appropriately.

• All patients should be given appropriate advice on lifestyle factors viz; cessation of smoking, regular exercise, diet, avoiding excess alcohol, achieving a satisfactory weight, reducing the use of added salt.

Management of Psychological impairment

• Patients with persistently depressed mood (duration at least one month) should be considered for antidepressant medication

• Antidepressants should be continued for at least 6 months, if a good response has been achieved.

Physiotherapy treatment

• Resisted exercise should be considered to improve motor function in targeted muscles.

• A physiotherapy treatment should be considered for improvement of any sort of movement disorder.

Six Ds for optimal management of stroke

Detection: Early recognition of stroke by patients and relatives
Dispatch: Immediate medical service activation
Door: Shifting the patient to hospital
Data: Neurologic examination and laboratory data
Decision: Therapeutic selection
Drug: Timely administration of appropriate drug

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