9.8 · Acute problems: Cerebrovascular disorders

Cerebrovascular disease

Any abnormality of the brain caused by a pathologic process in the blood vessels

Stroke

An acute focal neurological deficit from a vascular disorder that injures brain tissue

Results of stroke

Hypoxia, ischemia or infarction, and hemorrhage

Stroke risk factors

Age, sex, race, family history, hypertension, diabetes mellitus, asymptomatic carotid stenosis, hyperlipidemia, atrial fibrillation, and previous TIA or stroke

Stroke long-term deficits

Motor deficits, dysarthria and aphasia, and cognitive and other deficits

Thrombotic stroke

Large vessel stroke where a blood clot forms locally in large arteries within the brain such as the internal carotid, vertebral, or basilar

Origin of cerebral thrombi

Atherosclerosis, after plaque ruptures and a clot forms

Features of thrombotic stroke

Usually a single cerebral artery affecting the cerebral cortex, causing aphasia, neglect, and visual field defects; seen in older persons and may occur at rest

Lacunar stroke

Very small infarcts deep in the brain, from ischemia, small hemorrhages, or vasospasms

Lacunar stroke locations

Internal capsule, basal ganglia, and brain stem

Lacunar stroke manifestations

Purely sensory or motor hemiplegia and dysarthria, with regions of liquefactive necrosis in small lacunae

Lacunar stroke risk factors

Chronic hypertension and diabetes

Embolic stroke

Fragments break from a thrombus formed outside the brain, usually within the left heart but possibly the carotid artery

Most frequent site of embolic stroke

Middle cerebral artery, the terminus of the carotid artery

Onset of embolic stroke

Sudden, with immediate maximum deficit

Cardiac conditions causing emboli

Rheumatic heart disease, atrial fibrillation, recent heart attack, and patent foramen ovale

Transient ischemic attack (TIA)

Brain angina; temporary interruption in cerebral blood flow that reverses before infarction occurs, so it is not a stroke

TIA duration

Brief focal neurologic dysfunction usually lasting less than 1 hour with complete clinical recovery

TIA manifestations

Numbness in face, arm or leg, trouble speaking or understanding, poor vision in one or both eyes, confusion, and loss of balance

Likely cause of TIA

Platelet clumps or vessel narrowing with spasm causing intermittent blockage of circulation

Prognosis after TIA

High risk of repeat occurrence and eventual stroke if not treated

Hemorrhagic stroke

Rupture of a blood vessel with bleeding into tissue, forming a growing hematoma accompanied by edema; the most frequently fatal type

Onset of hemorrhagic stroke

Usually sudden and with activity

Causes of hemorrhagic stroke

Hypertension, ruptured aneurysms, and trauma

Manifestations of hemorrhagic stroke

Vomiting at outset and headache; hemorrhage into the basal ganglia produces contralateral hemiplegia

Great danger of hemorrhagic stroke

Increased intracranial pressure leading to coma and death

Intracranial aneurysm

Bulge in a blood vessel, varying from 2 mm to 2-3 cm, classified by shape as fusiform or berry

First indication of an aneurysm

Acute subarachnoid and/or intracerebral hemorrhage with excruciating headache, vomiting, and motor and sensory deficits

Aneurysm complications

Vasospasm near the aneurysm peaking 7 days after rupture, and hydrocephalus from plugging of arachnoid villi by products of blood lysis

Aneurysm treatment

Surgery to insert a metal clip around the neck of the aneurysm to protect from rebleeding; also coiling and stenting

Peak age of aneurysm rupture

About 50 years

Clinical manifestations of stroke

Sudden, usually one-sided symptoms depending on which cerebral artery and location are affected

Most common stroke deficit

Contralateral weakness of arm and face, sometimes leg

Stroke tone timeline

Initial flaccidity replaced by spasticity after 6-8 weeks

Other stroke manifestations

Numbness, monocular blindness, hemianopia, aphasia, dysarthria, and ataxia

Order of stroke deficits by frequency

Motor deficits most common, followed by language, sensation, and cognition

Stroke sensory deficits

Affect the body contralateral to the lesion and include paresthesias, neuropathic pain, and numbness