Disorders of the Cerebrovascular System

Abstract

The chapter begins with a discussion of common major clinical features and mechanisms of damage to the cerebrovascular system. Stroke is a general term that implies damage to cerebral tissue from insufficient blood to the brain (ischemic stroke or infarction), abnormal excess blood (hemorrhagic stroke or cerebral hemorrhage), or inadequate venous drainage of cerebral blood (venous stroke). Together, these act as the third leading cause of death in the USA. Signs and symptoms produced by strokes depend on which part of the brain is affected and whether the stroke causes increased intracranial pressure. This chapter further discusses the most common types of cerebrovascular disease: transient ischemic attack, ischemic or hemorrhagic stroke, and intracerebral hemorrhages from hypertension, aneurysms, and amyloidosis. Attention is given to their pathophysiology, major clinical features, major laboratory findings, and principles of management and prognosis.

A 65-year old previously healthy man who did not have a regular internist suddenly developed weakness and sensory loss in his right arm, leg, and face and also faced difficulty in speaking. He could understand his wife and knew what he wanted to say but could not get the words out. The episode lasted 20 min and spontaneously ended. He went to the emergency room (ER) where his neurologic examination was normal. He was diagnosed with a transient ischemic attack. The next day his echocardiogram was normal but the carotid artery Doppler ultrasound demonstrated that his left internal carotid artery narrowed by 85 %. In addition, the ER also found him to have several risk factors for transient ischemic attack (TIA) including being overweight by 45 lbs, an elevated blood pressure of 160/108, and a hemoglobin A1C of 8.6 %. The same day he met an internist to begin medical management for his hypertension, diabetes mellitus, and obesity plus a surgical referral to consider an elective carotid endarterectomy.

Video Legend

This video shows a 53 year-old woman s/p right middle cerebral artery stroke.

Segment 1: Cranial Nerve Exam

• Upper motor neuron facial weakness with lower face affected and normal strength in eyelid and forehead muscles.

• With a central lesion, weakness of trapezius but preserved ipsilateral sternocleidomastoid strength due to bilateral innervation.

Segment 2: Motor Exam

• Pyramidal weakness: upper extremity with extensor > flexor weakness

• Pyramidal weakness: lower extremity with flexor > extensor weakness

Segment 3: Sensory Exam

• Extinction to double simultaneous sensory stimulation

• Extinction to double simultaneous visual stimulation

Segment 4: Reflex Exam

• Hyperreflexia of left upper extremity with clonus at finger flexors

• Hoffman’s reflex showing flexion of thumb with “flicking” the terminal phalanx of middle finger

• Spontaneous Babinski sign

Segment 5: Gait Exam

• Stiff hemiparetic gait with extension at knee and hip