Stroke occurs when the blood supply to the brain or the part of the brain is cut off, due to which less oxygen is supplied to the brain & as a result the brain cells die, therefore stroke is a medical emergency.
TYPES OF STROKE
- Ischemic Stroke: When blood supply to the brain tissue is decreased leading to cell death & dysfunction in the particular area. It has four causes:
- Thrombosis: Obstruction due to a blood clot
- Embolism: Obstruction due a mass that has traveled from somewhere else.
- Systemic Hypoperfusion: General decrease in blood supply, like in shock.
- Cerebral Venous Sinus Thrombosis.
- Hemorrhagic Stroke: Bleeding that occurs due to a burst vein. It has two subtypes:
- Intracerebral Hemorrhage: Bleeding within the brain itself.
- Subarchanoid Hemorrhage: Bleeding between the internal meninges, it still occurs in the skull, but outside of the brain.
SIGNS & SYMPTOMS OF STROKE
- Sudden onset of facial weakness & numbness
- Drifting of one arm
- Difficulty in speech
- Facial palsy
- Initial muscle weakness followed by muscle overactivity.
- If the brain stem is involved, some symptoms that are seen are:
- Altered smell, taste, sensation.
- Drooping of the eyelids & weakness of the eye muscles.
- Decreased reflexes
- Problems in maintaining balance
- Altered breathing & heart rate
- In case the cerebral cortex is involved some symptoms are;
- Difficulty in verbal expression, reading & writing.
- Motor speech disorder
- Memory problems
- Lack of awareness
- Pressure ulcers
- Inability to perform learned movements
- Difficulty carrying out daily activities
- Loss of vision & speech
- Anxiety & Panic attacks
- Mania, apathy & psychosis
- Seizures & convulsions
- Deep Vein Thrombosis
- Pulmonary embolism
CAUSES & RISK FACTORS
- In thrombotic stroke, plaque formation in the vein occurs due to which clots are formed.
- Some diseases & risk factors that contribute to such kind of a stroke are;
- Sickle cell anemia, inflammation of the veins, atherosclerosis, vasoconstriction of the arteries in the brain, etc.
- In an embolic stroke, particles of mass, like air, fat, or bacteria that are traveling in the blood, can cause a blockage in the brain.
- Risk factors include, arrhythmia, Deep vein thrombosis, infective inflammation of the endometrium of the heart, calcium deposits in the heart valve.
- Cerebral hypoperfusion in which blood supply is cut off to all parts of the brain can be due to; myocardial infarction, pulmonary embolism, accumulation of fluid in the heart sac, hypoxia.
- Intracerebral hemorrhage is due to hypertension, some risk factors are; trauma, bleeding disorders, illicit drug use, etc.
- Some other risk factors & diseases that can increase the chances of stroke are;
- Diabetes Mellitus
- End stage Kidney disease
- Heavy alcohol use & smoking
- Lack of physical activity & being obese
- Consumption of red meat
DIAGNOSIS OF STROKE
- Physical examination of the symptoms which can give an estimation of the severity of the stroke.
- Imaging Tests in ischemic & hemorrhagic stroke are as follows:
- For diagnosing ischemic stroke in emergency settings
- CT scans (without contrast enhancements)
sensitivity= 16% (less than 10% within first 3 hours of symptom onset)
- MRI scans
- For diagnosing hemorrhagic stroke in emergency settings
- CT scans (without contrast enhancements)
- MRI scan
When a stroke is diagnosed various other tests are conducted for further classification to determine the cause:
- Ultrasound for narrowed carotid arteries.
- ECG to identify arrhythmia or clots in the heart.
- Holter Monitor study.
- Angiogram of the cerebral vasculature.
- Blood tests for determining blood cholesterol & activity of clotting factors.
- For controlling hypertension, anti-hypertensives of the class Beta blockers, ACE inhibitors, CCBs are given.
- Reduction of blood cholesterol levels by prescription of statins.
- Anti-diabetic medications to control blood sugar levels.
- Anti-coagulants are given to prevent formation of clots.
- Blood thinning medication like Aspirin.
- Surgery for narrowed carotid artery by angioplasty can prevent future episodes of stroke.
- Thrombectomy, a mechanical procedure used for breaking down clots in the blood vessels.
- In a medical procedure, an anti-coagulant medication is injected through a catheter in an artery, which travels to the site of clot in the brain, to break down the clot.
- Craniectomy, a surgical procedure which involves the removal of one side of the skull to prevent complications arising from swelling in the brain.
- Surgery to manage burst aneurysm, for removing pooled up blood & management of the burst artery.
MANAGEMENT & PREVENTION OF STROKE
- In patients who have suffered from stroke, rehabilitation therapy is followed up, which may include;
- Physical therapy
- Occupational therapy
- Speech & language therapy
- Use of wheelchairs & ankle foot orthoses.
- Motor learning
- Assistance in learning activities of daily lives, in other words, speech, eating, movement, reading, etc.
- Assistance in eating food by inserting a nasogastric tube.
- Electrical stimulation & magnetic stimulation for the patient.
- Modernistic therapies like virtual reality & robot assistance.
- For prevention of stroke;
- Proper diet, that is low on sugar, salt, fats & cholesterol.
- Maintaining a healthy weight & physical exercise.
- Management of other diseases & conditions.