Cerebrovascular Accident

Only available on StudyMode
  • Download(s) : 351
  • Published : September 11, 2009
Open Document
Text Preview
CEREBROVASCULAR ACCIDENT

Cerebrovascular accident, termed as “brain attack,” is also referred to as Stroke. Stroke is a sudden loss of function resulting from a disruption of the blood supply to a localized part of the brain.

The mortality and morbidity of CVA in the Philippines is relatively low.

There are two types of stroke:

1. Ischemic Stroke is a disruption of the blood supply due to an obstruction, usually thrombus or embolism that causes infarction of brain tissue.

2. Hemorrhagic Stroke is caused primarily by an intracranial or subarachnoid hemorrhage. It may also be due to spontaneous rupture of small vessels primarily related to hypertension, subarachnoid hemorrhage due to a ruptured aneurysm or intracranial hemorrhage related to amyloid angiopathy, arterial venous malformations, intracranial aneurysms, or medications such as anticoagulants.

Types of Ischemic Stroke:

• Large Artery Thrombotic Strokes are due to atherosclerotic plaques in the large blood vessels of the brain. Thrombus formation and occlusion at the site of the atherosclerosis result in ischemia and infarction.

• Small Penetrating Artery Thrombotic Strokes affects one or more vessels and are the most common type of ischemic stroke. It is also called Lacunar Strokes because of the cavity that is created once the infracted brain tissue disintegrates.

• Cardiogenic Embolic Strokes are associated with cardiac dysrythmias, usually atrial fibrillation. Emboli originate from the heart and circulate to the cerebral vasculature, most commonly the left middle cerebral artery, resulting in stroke. Embolic stroke may be prevented by the use of anticoagulation therapy in patients with atrial fibrillation.

• The last two classifications of ischemic strokes are cryptogenic strokes, which have no known cause, and other strokes, from causes such as cocaine use, coagulopathies, migraine, and spontaneous dissection of the carotid or vertebral arteries.

CLINICAL MANIFESTATIONS:

An ischemic stroke can cause a wide variety of neurologic deficits, depending on the location of the lesion, the size of the area of inadequate perfusion, and the amount of collateral blood flow.

They may present with the following symptoms:
• Numbness or weakness of the face, arm or leg, especially on one side of the body. • Confusion or change in mental status
• Trouble speaking or understanding speech
• Visual disturbances
• Difficulty walking, dizziness, or loss of balance or coordination • Sudden severe headache
• Perceptual disturbances

Motor Loss

A stroke is lesion of the upper motor neurons and results in loss of voluntary control over movements. A disturbance of voluntary motor control on one side of the body may reflect damage to the upper motor neurons on the opposite side of the brain.

Hemiplegia (paralysis of one side of the body) is the most common motor dysfunction due to a lesion of the opposite side of the brain. Hemiparesis or weakness of one side of the body is another sign.

Communication Loss

Other brain functions affected by stroke are language and communication. Stroke is most common cause of aphasia.

Dysarthria (difficulty of speaking) is caused by paralysis of the muscles responsible for producing speech. Dysaphasia or Aphasia (defective speech or loss of speech), which can be expressive aphasia, receptive aphasia or global (mixed) aphasia. Apraxia (inability to perform a previously learned action), as may be seen when a patient picks up a fork and attempts to comb his hair with it.

Perceptual Disturbances

Perception is the ability to interpret sensation.

Visual-perceptual dysfunctions are due to disturbances of the primary sensory pathways between eye and visual cortex. Homonymous hemianopsia (loss of half of the visual field) may occur from stroke and may be temporary or permanent.

Disturbances in visual-spatial relations are frequently seen in...
tracking img