STROKE: A Common Medical Emergency


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Cerebrovascular disease is the most common cause of death after Cancers and Ischemic Heart Disease in developed countries.
Stroke is more common than other cerebrovascular diseases and the third most common cause of death in high-income countries. Stroke results in a focal neurological deficit of brain function due to loss of/ impaired blood supply (ischemia) or bleeding within the brain (haemorrhage).
Stroke is a common medical emergency and the chance increases with increasing age, About one-fifth of the patients with an acute attack die within a month of the event and at least half of the patient live with a physical disability.
About 80-85% of stroke occurs due to inadequate blood flow to part of the brain and most common pathophysiology of stroke is either embolism (dislodgement of a blood clot from cardiac or other major blood vessels) or thrombosis (occlusion of a vessel by blood clot or deposition of fat within the wall of the vessel) of any local blood vessel of the brain.

Pathologically Stroke can be classified into-

  1. Ischemic Stroke: due to the impaired blood supply to the part of the brain.
  2. Haemorrhagic Stroke: due to haemorrhage from ruptured blood vessels.

Clinical Classification of Stroke:

A. Ischemic Stroke:

 a. Anterior Circulation Stroke:

  • Total anterior circulation stroke
  • Partial anterior circulation stroke
  • Lacunar stroke

 b. Posterior Circulation Stroke.

B. Haemorrhagic Stroke:

  • Intercerebral
  • Subarachnoid 
Although ischemic stroke is more common than haemorrhagic stroke, early mortality due to stroke is higher in haemorrhagic stroke.

Causes of Stroke:

A. Causes of Ischemic Stroke:
  1. Thrombosis of vessels supplying the brain.
  2. Large artery stenosis (narrowing).
  3. Small vessel disease (most common in patient with prolonging high blood pressure).
  4. Too low blood pressure fails to supply the brain.
B. Causes of Haemorrhagic Stroke:
  1. Arteriovenous malformations i.e. structural defects of vessels supplying the brain.
  2. Bleeding disorder.
  3. Head injury following trauma or accident (extracranial haemorrhage).
  4. Anticoagulant drug therapy.

Risk Factors:

There are numerous risk factors, related to stroke. They are divided into two categories.

A. Non-modifiable Risk Factors:

  • Increasing age.
  • Male predominant (except extreme of age).
  • Race: Afro-Caribbean> Asian> European.
  • Heredity i.e. positive family history of Stroke or other cerebrovascular diseases.
  • Previous vascular events, like Myocardial Infarction, Stroke, Peripheral vascular disease.
  • High fibrinogen level.

B. Modifiable Risk Factors:

  • Hypertension.
  • Diabetes mellitus.
  • Hyperlipidemia.
  • Cigarette smoking.
  • Excessive alcohol consumption.
  • Oestrogen-containing drugs: Oral contraceptive pill, Hormone replacement therapy.
  • Heart disease: Atrial fibrillation, Congestive Cardiac Failure, Infective endocarditis.
  • Polycythemia.

Clinical Presentations of Stroke:

  1. Unilateral weakness is the classical presentation of stroke. The weakness is sudden and progresses rapidly.
  2. Speech disturbances: Dysphagia and Dysarthria are the most common presentations of disturbed speech. (Dysphagia indicates damage to the frontal or parietal lobe).
  3. Visual disturbances or photophobia.
  4. Ataxia: if stroke causing damage to the cerebellum & its connections.
  5. Headache: although sudden severe headache is the cardinal symptom of Subarachnoid haemorrhage, it can be seen in stroke too.
  6. Neck rigidity.
  7. Hypertension.

Differential Diagnosis of Stroke: 

Stroke often mimics with-
  • Cerebral tumour (both primary and metastasized).
  • Subdural haematoma.
  • Cerebral abscess.
  • Hypoglycemia.
  • Migraine
  • Hemiplegia
  • Conversion disorder.

Investigations:

A range of investigation may be required, to diagnose the disease. 
  • CT scan.
  • Doppler or Duplex scanning.
  • Blood test for blood glucose, Serum Triglycerides, Cholesterol level
  • Complete blood count to diagnose polycythemia.
  • ECG or Echocardiography.                 
Lumbar puncture is usually not done for diagnosis of stroke. 

Management of Acute Stroke:

Immediate hospitalisation is necessary as it is a medical emergency. 
The aim of the treatment is the maintenance of airway, breathing, circulation and nutrition, regulation of blood pressure and temperature and prevention of dehydration.
Usually, blood pressure returns toward normal within a few days.

Complications of Stroke:

  1. Chest infection or bronchopneumonia.
  2. Epileptic seizure.
  3. Deep venous thrombosis & pulmonary embolism.
  4. Painful shoulder.
  5. Pressure sore or bed sore.
  6. Depression & anxiety.
  7. Physical disability like hemiplegia or paralysis.
Although the incidence increases with age, the chances of the disease can be reduced by adopting some healthy lifestyles, like avoiding smoking, alcohol consumption, by doing regular exercise, controlling hypertension, diabetes, hyperlipidemia.
Regular check-up of blood pressure, blood glucose, serum lipid profile, after a certain age, is also an important way of preventing acute stroke.

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