Cerebral Vascular Disease

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Rapid development of focal or global disturbance of cerebral function:

  • – Duration < 24 hours is a transient ischemic attack

  • – Duration > 24 hours is a stroke

• Early CT scan is negative, which excludes intracerebral or subarachnoid hemorrhage

• Duplex ultrasound (neck) or angiography (head) shows large-vessel disease

GENERAL CONSIDERATIONS

• Acute cerebrovascular disorders cause more morbidity and mortality than any other disease in those over age 45 years

• In North America, about 80% of strokes are ischemic and are caused by thrombosis in cerebral arteries, emboli to the brain arteries, or hypertension

• Hemorrhagic strokes are more common in East Asia and are due to rupture of an intracerebral artery

• About 25% of ischemic strokes are from cardiac emboli

• 25% are lacunar (deep brain and small)

• 25% are due to large-vessel atherosclerosis

• 5% are due to less common causes such as dissection or vasculitis

• 20% are of uncertain etiology

• Risk factors for stroke include

  • – Hypertension (most important)

  • – Smoking

  • – Atrial fibrillation

  • – Diabetes

  • – Elevated cholesterol levels

  • – Hypercoagulability or oral contraceptive use

  • – Cocaine or methamphetamine use

  • – Migraine headaches

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Transient ischemic attack:

  • – Focal neurologic defects that usually last < 1 hour but certainly last < 24 hours without evidence of cerebral infarction

• Stroke:

  • – Sudden numbness or weakness of the face, arm, or leg

  • – Sudden decrease in vision in 1 or both eyes

  • – Sudden loss of balance or coordination or difficulty walking

  • – Impaired consciousness or difficulty in speaking or understanding

  • – Sudden severe headache of unknown cause

  • – In some instances, symptoms are not sudden but gradually progress over a few days

PHYSICAL EXAM FINDINGS

• Unilateral or bilateral motor defects

• Unilateral or bilateral sensory defects

• Aphasia or dysphagia

• Monocular vision problems

• Hemianopia

• Atypical—confusion, vertigo, dizziness

DIFFERENTIAL DIAGNOSIS

• Subdural hematoma

• Epilepsy

• Migraine

• Hypoglycemia or hyperglycemia

• Vertigo

• Hypertensive encephalopathy

• Cerebral infection

• Brain tumor

• Multiple sclerosis

• Bell’s palsy

• Neuropathies

• Transient global amnesia

• Hyponatremia

• Hepatic or renal encephalopathy

• Drug overdose

• Spinal cord disease

• Hysterical conversion

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• CBC, electrolytes, glucose, creatinine, BUN

• Coagulation studies

• Lipid panel, homocysteine

• Cardiac biomarkers (troponins)

• Other specific tests based on the specific patient (eg, toxicology screen)

ELECTROCARDIOGRAPHY

• ECG abnormalities are common, but specific findings may suggest the cause of the stroke, such as myocardial infarction or atrial fibrillation

• Prolonged QT and torsades de pointes can occur as a result of a stroke

IMAGING STUDIES

• CT scan to distinguish ischemia from hemorrhage

• Magnetic resonance angiography in selected patients to detect vascular occlusion

• Duplex ...