Ischaemic Stroke: A Comprehensive Guide

Overview

An ischaemic stroke occurs when a blood clot blocks or narrows an artery leading to the brain, causing a severe reduction in blood flow (ischaemia). This deprives brain tissue of oxygen and nutrients, leading to cell death within minutes. Ischaemic strokes account for about 87% of all strokes (CDC, 2023).

Who it affects: While strokes can occur at any age, the risk increases with age. About two-thirds of strokes occur in people over 65 (NIH). However, younger adults, including those in their 30s and 40s, can also experience strokes, especially with risk factors like obesity or diabetes.

Prevalence: Stroke is a leading cause of death and disability worldwide. In the U.S., someone has a stroke every 40 seconds, and someone dies from a stroke every 3.5 minutes (CDC).

Symptoms

Symptoms of an ischaemic stroke appear suddenly and vary depending on the area of the brain affected. Use the FAST acronym to recognize common signs:

• Face drooping: One side of the face may droop or feel numb. Ask the person to smile—is the smile uneven?
• Arm weakness: One arm may feel weak or numb. Ask the person to raise both arms—does one arm drift downward?
• Speech difficulty: Speech may be slurred or hard to understand. Ask the person to repeat a simple sentence—can they do it correctly?
• Time to call emergency services: If someone shows any of these symptoms, call for help immediately.

Other symptoms may include:

• Sudden numbness or weakness in the leg, arm, or face (especially on one side)
• Confusion or trouble understanding speech
• Vision problems in one or both eyes (blurred, blackened, or double vision)
• Trouble walking, dizziness, or loss of balance/coordination
• Severe headache with no known cause

Symptoms may come and go in a transient ischaemic attack (TIA), often called a "mini-stroke." TIAs are warning signs and require immediate medical attention.

Causes and Risk Factors

Ischaemic strokes occur due to blocked or narrowed arteries. Common causes include:

• Thrombotic stroke: A blood clot (thrombus) forms in one of the arteries supplying blood to the brain.
• Embolic stroke: A clot forms elsewhere (often the heart) and travels to the brain via the bloodstream.

Risk factors:

• Modifiable risk factors:
  • High blood pressure (hypertension)
  • Smoking or tobacco use
  • High cholesterol
  • Diabetes
  • Obesity or physical inactivity
  • Atrial fibrillation (irregular heartbeat)
  • Poor diet (high in saturated fats, salt, or cholesterol)
• Non-modifiable risk factors:
  • Age (risk increases after 55)
  • Family history of stroke
  • Gender (men have higher risk, but women are more likely to die from stroke)
  • Race (African Americans, Hispanics, and Asian Americans have higher risk)

Diagnosis

Quick diagnosis is critical for effective treatment. Doctors use several tests to determine the type of stroke and its location:

• Physical examination: Assessing symptoms, medical history, and risk factors.
• Imaging tests:
  • CT scan: Shows bleeding in the brain (hemorrhagic stroke) or blockages (ischaemic stroke).
  • MRI: Provides detailed brain images to detect tissue damage.
  • Carotid ultrasound: Checks for narrowing in the neck arteries.
  • Cerebral angiogram: Uses dye and X-rays to visualize blood flow in brain arteries.
• Heart tests: EKG or echocardiogram to check for heart-related causes (e.g., atrial fibrillation).
• Blood tests: Measure clotting time, cholesterol, and blood sugar levels.

Treatment Options

Treatment depends on the stroke's severity and timing. Early intervention improves outcomes.

Emergency Treatments

• Clot-busting drugs (thrombolytics): Alteplase (tPA) dissolves clots if given within 4.5 hours of symptom onset (Mayo Clinic).
• Mechanical thrombectomy: A catheter removes large clots in major brain arteries, effective up to 24 hours in some cases (NIH).

Medications

• Antiplatelets: Aspirin or clopidogrel to prevent future clots.
• Anticoagulants: Warfarin or apixaban for atrial fibrillation.
• Statins: Lower cholesterol to reduce plaque buildup.
• Blood pressure medications: ACE inhibitors or diuretics to manage hypertension.

Procedures

• Carotid endarterectomy: Surgical removal of plaque from neck arteries.
• Angioplasty/stenting: Opens narrowed arteries with a balloon or stent.

Rehabilitation

Post-stroke recovery may involve:

• Physical therapy (regaining movement)
• Occupational therapy (daily living skills)
• Speech therapy (communication and swallowing)
• Psychological support (depression or anxiety management)

Living with Ischaemic Stroke

Recovery varies—some regain full function, while others face long-term disabilities. Tips for daily management:

• Follow medical advice: Take prescribed medications and attend follow-up appointments.
• Adapt your home: Install grab bars, remove trip hazards, and use assistive devices if needed.
• Stay active: Engage in recommended exercises to improve mobility and strength.
• Eat a healthy diet: Focus on fruits, vegetables, whole grains, and lean proteins (Mediterranean or DASH diet).
• Monitor mental health: Seek support for depression or anxiety, which are common post-stroke.
• Join support groups: Connect with others who understand the challenges.

Prevention

Up to 80% of strokes are preventable (WHO). Key strategies:

• Control blood pressure: Aim for <120/80 mmHg (CDC).
• Quit smoking: Smoking doubles stroke risk (Mayo Clinic).
• Manage diabetes: Keep blood sugar levels in check.
• Exercise regularly: Aim for 150 minutes of moderate activity weekly (NIH).
• Limit alcohol: No more than 1 drink/day for women, 2 for men (Cleveland Clinic).
• Eat a balanced diet: Reduce salt, saturated fats, and cholesterol.
• Treat atrial fibrillation: Manage irregular heartbeats with medication.

Complications

Without prompt treatment, ischaemic strokes can lead to:

• Paralysis or muscle weakness (often on one side of the body)
• Speech or language difficulties (aphasia)
• Memory loss or cognitive decline
• Emotional changes (depression, anxiety, or mood swings)
• Chronic pain (e.g., post-stroke shoulder pain)
• Seizures or epilepsy
• Death (stroke is the 5th leading cause of death in the U.S.)

When to Seek Emergency Care

Sources

• Centers for Disease Control and Prevention (CDC). (2023). Stroke Facts.
• National Institute of Neurological Disorders and Stroke (NIH). (2023). Stroke Information.
• Mayo Clinic. (2023). Ischaemic Stroke.
• World Health Organization (WHO). (2023). Stroke Prevention.
• Cleveland Clinic. (2023). Stroke Recovery.