Stroke
Content of This Page
1- Introduction
2- Causes
3- Symptoms
4- Types of Stroke
5- Investigations & Lab Results
6- Risk Factors
7- Complications
8- Treatment
Introduction
A Stroke is a medical emergency that occurs when the blood supply to part of the brain is interrupted or reduced, preventing brain tissue from getting the oxygen and nutrients it needs. Within minutes, brain cells begin to die, making timely treatment critical. Strokes can be caused by a blockage (ischemic stroke) or bleeding in the brain (hemorrhagic stroke). A transient ischemic attack (TIA), often called a mini-stroke, is a temporary disruption of blood flow that serves as a warning sign for future strokes. Stroke is a leading cause of death and long-term disability worldwide. Understanding the symptoms, risk factors, and the importance of rapid intervention can greatly improve outcomes and save lives.
Causes
1. Ischemic Stroke (Most Common – ~85% of strokes)
Occurs when a blood clot blocks or narrows a blood vessel in the brain, reducing blood flow.
Causes include:
Atherosclerosis: Buildup of fatty deposits in arteries.
Blood clots: Can form in the heart (e.g., due to atrial fibrillation) and travel to the brain.
Carotid artery stenosis: Narrowing of arteries in the neck supplying the brain.
Heart conditions: Such as heart attack or irregular heartbeat (especially atrial fibrillation).
2. Hemorrhagic Stroke
Caused by bleeding in or around the brain due to a ruptured blood vessel.
Causes include:
High blood pressure (hypertension): Most common cause.
Aneurysms: Weak spots in blood vessel walls that can burst.
Arteriovenous malformations (AVMs): Abnormal tangles of blood vessels.
Trauma: Head injury causing brain bleeding.
Blood-thinning medications: Like warfarin or aspirin in high doses.
3. Transient Ischemic Attack (TIA)
A “mini-stroke” caused by a temporary blockage, without lasting damage.
Causes are similar to ischemic stroke, including:
Small clots
Temporary narrowing of blood vessels
Atrial fibrillation
Symptoms
-Main Symptoms of Stroke (Remember: FAST)
A simple way to recognize stroke symptoms quickly is the FAST acronym:
F – Face drooping: One side of the face may droop or feel numb. Ask the person to smile — the smile may be uneven.
A – Arm weakness: One arm may feel weak or numb. Ask the person to raise both arms — one arm may drift downward.
S – Speech difficulty: Speech may be slurred, or the person may be unable to speak or understand speech clearly.
T – Time to call emergency services: If any of these signs are present, seek immediate medical help — time is critical.
-Other Symptoms May Include:
Sudden numbness or weakness in the face, arm, or leg, especially on one side of the body
Sudden confusion or trouble understanding
Sudden trouble seeing in one or both eyes
Sudden trouble walking, dizziness, loss of balance or coordination
Sudden severe headache with no known cause (especially in hemorrhagic stroke)
Difficulty swallowing (dysphagia)
Sudden loss of consciousness or fainting (in some cases)
-Symptoms Specific to Hemorrhagic Stroke:
Sudden, very severe headache (“thunderclap headache”)
Nausea or vomiting
Seizures
Sensitivity to light
Loss of consciousness
Types of Stroke
1. Ischemic Stroke
Cause: A blockage in an artery supplying blood to the brain.
Accounts for: About 85% of all strokes.
Subtypes:
Thrombotic stroke: A blood clot forms in an artery in the brain.
Embolic stroke: A clot forms elsewhere (e.g., heart) and travels to the brain (common in atrial fibrillation).
2. Hemorrhagic Stroke
Cause: A blood vessel in the brain bursts, causing bleeding into or around the brain.
Accounts for: About 15% of strokes, but is more deadly.
Subtypes:
Intracerebral hemorrhage: Bleeding directly into the brain tissue.
Subarachnoid hemorrhage: Bleeding into the space between the brain and the thin tissues covering the brain (often due to an aneurysm rupture).
3. Transient Ischemic Attack (TIA)
Also called: “Mini-stroke”
Cause: A temporary blockage in a blood vessel.
Symptoms: Similar to a stroke but last only a few minutes to hours and cause no permanent damage.
4. Brain Stem Stroke
Can be ischemic or hemorrhagic
Affects: The brain stem — controls vital functions like breathing, heartbeat, and eye movements.
Symptoms: Can affect both sides of the body and may cause locked-in syndrome (in severe cases).
Investigations & Lab Results
1. Brain Imaging (Crucial for Diagnosis)
These tests help distinguish between ischemic and hemorrhagic strokes.
Non-Contrast CT Scan
Purpose: First-line imaging to rule out hemorrhage.
Findings:
Ischemic stroke: May appear normal early; later shows hypodensity.
Hemorrhagic stroke: Appears as a hyperdense (bright) area due to bleeding.
MRI Brain
Purpose: More sensitive for early ischemic changes.
Findings: Detects infarction within minutes of onset.
CT Angiography / MR Angiography
Purpose: Visualizes cerebral vessels to detect blockages, stenosis, or aneurysms.
2. Blood Tests
Complete Blood Count (CBC)
Checks for anemia, infection, or thrombocytopenia.
Blood Glucose
Hypoglycemia or hyperglycemia can mimic or worsen stroke symptoms.
Coagulation Profile (PT/INR, aPTT)
Assesses bleeding risk and suitability for thrombolytic therapy (e.g., tPA).
Renal Function and Electrolytes (Urea, Creatinine, Na⁺, K⁺)
Evaluates metabolic status and kidney function.
Lipid Profile
Assesses cholesterol levels, a key stroke risk factor.
Cardiac Enzymes (Troponin)
Detects myocardial damage if a cardiac cause is suspected.
3. Cardiac Investigations
Electrocardiogram (ECG)
Detects arrhythmias such as atrial fibrillation.
Echocardiogram
Identifies cardiac sources of emboli (e.g., thrombi, valvular disease).
Holter Monitor (24–72 hours)
Useful for detecting intermittent arrhythmias.
4. Other Relevant Tests
Carotid Doppler Ultrasound
Evaluates for carotid artery stenosis or occlusion.
Blood Cultures
Ordered if infective endocarditis or sepsis is suspected.
Toxicology Screen
Performed if drug use is a possible cause (especially in young patients).
Risk Factors
1. Modifiable Risk Factors
These can be managed or reduced through lifestyle changes, medication, or treatment.
Hypertension (High blood pressure) – Most significant risk factor for both ischemic and hemorrhagic stroke.
Diabetes mellitus – Increases risk of atherosclerosis and clot formation.
Hyperlipidemia (High cholesterol) – Contributes to plaque buildup in arteries.
Smoking – Damages blood vessels and promotes clot formation.
Atrial fibrillation – Irregular heartbeat that increases risk of embolic stroke.
Heart disease – Including heart failure, valve disease, or previous myocardial infarction.
Obesity – Associated with high blood pressure, diabetes, and heart disease.
Physical inactivity – Linked to multiple cardiovascular risk factors.
Excessive alcohol intake – Increases blood pressure and stroke risk.
Drug abuse – Especially cocaine, amphetamines, and other stimulants.
Unhealthy diet – High in salt, sugar, and saturated fats.
2. Non-Modifiable Risk Factors
These cannot be changed but help identify individuals at higher risk.
Age – Risk increases significantly after age 55.
Sex – Men have a higher risk, but women tend to have worse outcomes.
Family history of stroke – Genetic factors may play a role.
Ethnicity – Higher risk in African, Hispanic, and South Asian populations.
Previous stroke or TIA – Strong predictor of future stroke.
Complications
1. Neurological Complications
Paralysis or Weakness
Often affects one side of the body (hemiplegia or hemiparesis).
Speech and Language Disorders
Aphasia: Difficulty speaking or understanding language.
Dysarthria: Slurred or slow speech due to weak muscles.
Cognitive Impairment
Problems with memory, attention, learning, or judgment.
Seizures
Especially common after hemorrhagic strokes or cortical involvement.
Vision Problems
Loss of part of the visual field (e.g., hemianopia), double vision, or visual neglect.
Sensory Disturbances
Numbness, tingling, or pain (central post-stroke pain syndrome).
2. Functional and Physical Complications
Swallowing Difficulties (Dysphagia)
Increases risk of aspiration pneumonia and malnutrition.
Incontinence
Loss of bladder or bowel control, especially in the acute phase.
Spasticity and Contractures
Muscle stiffness or abnormal limb positioning due to nerve damage.
Deep Vein Thrombosis (DVT)
Caused by immobility; can lead to pulmonary embolism.
Shoulder Subluxation or Pain
From muscle weakness or poor positioning.
3. Psychological and Emotional Complications
Depression and Anxiety
Common due to the impact of stroke on independence and function.
Emotional Lability (Pseudobulbar Affect)
Inappropriate or uncontrollable laughing or crying.
Post-Stroke Fatigue
Persistent tiredness not explained by exertion.
4. Social and Quality of Life Impacts
Loss of Independence
Many stroke survivors require assistance with daily living activities.
Social Isolation
Due to communication difficulties or physical limitations.
Financial Burden
Costs related to long-term care, rehabilitation, or loss of income.
Treatment
1. Immediate (Emergency) Treatment
A. Ischemic Stroke
Goal: Restore blood flow as quickly as possible.
Key interventions:
Intravenous thrombolysis (tPA/alteplase)
Must be given within 4.5 hours of symptom onset.
Requires CT scan first to rule out hemorrhage.
Mechanical thrombectomy
Removal of a large clot via catheter (within 6–24 hours in selected patients).
Aspirin
Started within 24–48 hours after confirming it’s not a hemorrhagic stroke.
B. Hemorrhagic Stroke
Goal: Control bleeding and reduce pressure in the brain.
Key interventions:
Blood pressure control (e.g., IV labetalol, nicardipine).
Reversal of anticoagulation if patient is on warfarin or DOACs.
Surgery may be needed to relieve pressure (e.g., craniotomy, clipping an aneurysm).
2. Supportive and General Measures
Airway, Breathing, Circulation (ABCs)
Blood glucose control
Management of fever or infection
Prevention of complications (e.g., DVT prophylaxis, pressure sore prevention)
3. Secondary Prevention
Prevent future strokes through long-term strategies.
For Ischemic Stroke:
Antiplatelet therapy
Aspirin, clopidogrel, or combination (short term).
Anticoagulation
For atrial fibrillation or cardiac embolic sources (e.g., warfarin, DOACs).
Statins
Lower cholesterol and stabilize plaques.
Blood pressure control
Diabetes management
Lifestyle changes
Smoking cessation, diet, exercise, weight control, reduced alcohol intake.
For Hemorrhagic Stroke:
Control of hypertension
Avoidance of anticoagulants or antiplatelets unless clearly indicated
Surgical management if structural cause present (e.g., AVM, aneurysm)
4. Rehabilitation
Multidisciplinary team approach
Physiotherapy, occupational therapy, speech therapy, and psychological support.
Goal: Restore function, improve independence, and enhance quality of life.