Q 2.17. Asymptomatic cerebrovascular disease. Transient ischemic attacks.

Clinical Case: Mr. Macron, a 46-year-old man, presents to the emergency department with sudden onset weakness on the right side of his body that lasted for a few minutes. He reports a brief episode of slurred speech and difficulty in understanding words. However, by the time he arrives at the hospital, his symptoms have completely resolved. Upon further inquiry, Mr. Macron mentions similar episodes occurring intermittently over the past few weeks.

Clinical Case Continued: Following Mr. Macron’s presentation, he undergoes a thorough evaluation, including MRI and vascular imaging, which reveal evidence of cerebral small vessel disease and carotid artery stenosis. He is started on antiplatelet therapy and lipid-lowering medications and is referred for further vascular assessment and lifestyle modification counseling.

1. Asymptomatic Cerebrovascular Disease:

• Definition: Asymptomatic cerebrovascular disease refers to the presence of vascular pathology in the brain without overt clinical symptoms.
• Key Feature: It often precedes transient ischemic attacks (TIAs) or strokes and is commonly detected incidentally on imaging studies.

2. Transient Ischemic Attacks (TIAs):

• Definition: TIAs are brief episodes of neurological dysfunction caused by temporary disruption of blood flow to a specific part of the brain.
• Clinical Appearance:
  • Sudden Onset Symptoms: Typically include weakness or numbness in the face, arm, or leg, especially on one side of the body.
  • Speech Changes: Slurred speech or difficulty in understanding or producing speech.
  • Visual Disturbances: Blurred or double vision.
• Duration: Symptoms resolve within 24 hours, usually lasting only a few minutes to a few hours.

3. Pathophysiology:

• Atherosclerosis: Narrowing of blood vessels due to the buildup of plaques, leading to reduced blood flow to the brain.
• Embolism: Formation of blood clots elsewhere in the body (e.g., heart) that travel to the brain and cause temporary blockages.
• Hypoperfusion: Transient reduction in cerebral blood flow due to systemic hypotension or vascular spasm.

4. Diagnosis:

• Clinical Assessment: Detailed history and physical examination focusing on neurological symptoms and risk factors for cerebrovascular disease.
• Imaging Studies: MRI or CT scans of the brain to assess for evidence of acute or chronic cerebrovascular disease.
• Vascular Imaging: Doppler ultrasound, CT angiography, or magnetic resonance angiography to evaluate blood flow and detect stenosis or occlusion in cerebral arteries.

Clinical Findings on Imaging:

• MRI: May reveal acute ischemic changes such as hyperintense signals on diffusion-weighted imaging (DWI). Chronic changes include white matter hyperintensities, lacunar infarcts, and cerebral microbleeds.
• CT: Can detect acute ischemic changes, intracranial hemorrhage, and evidence of chronic ischemic disease such as cerebral atrophy and calcifications.

5. Treatment:

• Lifestyle Modifications: Smoking cessation, regular exercise, healthy diet, and management of hypertension, diabetes, and hyperlipidemia.
• Medications: Antiplatelet agents (e.g., aspirin, clopidogrel) to prevent clot formation and statins to lower cholesterol levels.
• Surgical Intervention: Carotid endarterectomy or angioplasty with stent placement for severe carotid artery stenosis.

In the table below are summarised the key differences between a TIA and a Stroke