A cerebrovascular accident results from impaired circulation in one or more of the brain’s blood vessels. Impairments are usually caused by:
The most common cause of CVA, which is usually related to atherosclerosis. Plaque and atheromatous deposits gradually occlude the artery. Occlusion leads to ischemia and infarction of brain tissue, followed by edema and necrosis. It usually occurs in the extracerebral vessels but sometimes occurs in the intracerebral vessels.
The most devastating cause of CVA, hemorrhage occurs when a cerebral vessel ruptures and bleeds into brain tissue or subarachnoid space. Usually results from a rupturing arteriosclerotic vessel caused by exposure to prolonged hypertension, a cerebral aneurysm. Effects may be severe. More than 50% of patients die within the first 3days from brain herniation.
Photographs show acute, massive hypertensive hemorrhages. Note that the blood here is under enough driving pressure to destroy the tissue, rupture through the ependymal lining and fill the ventricle with blood. When massive, these tend to be fatal events.
C . EMBOLISM Usually, fragments break off from a mural thrombus in the left atrium or ventricles or from bacterial vegetations affecting heart valves. These emboli travel through the carotid artery and typically lodge in the smaller cerebral vessels. It may occur quite suddenly, often followed by necrosis and edema .
D. Interruptions of blood supply to brain via carotid and vertebral-basilar arteries--- causes’ cerebral anoxia. E. Cerebral anoxia longer than ten minutes to a localized area of brain—causes cerebral infarction (irreversible changes). F. Surrounding edema and congestion causes further dysfunction. G. Lesion in cerebral hemisphere (motor cortex, internal capsule, basal ganglia)—results in manifestations on the contralateral side. H. Permanent disability unknown until edema subsides. Order in which function may return: facial, swallowing, lower limbs, speech, arms.
Sudden, brief episodes of neurologic deficits caused by focal cerebral ischemia. It usually lasts 5 to 20 minutes and is followed by a rapid clearing of neurologic deficits (typically within 24 hours). Recurrent attacks are common.
A brief reversible episode of neurologic dysfunction caused by temporary interruption of blood supply to the brain.
Also called “intermittent cerebrovascular insufficiency”.
High blood pressure. You can lower your risk of TIA by lowering your blood pressure.
High cholesterol. High cholesterol increases your risk of atherosclerosis, which can lead to blood clots. By lowering your cholesterol, you can lower your chance of having a TIA.
Smoking. If you stop smoking, you can lower your risk of having a TIA.
Heart disease. The higher your risk of heart attack, the higher your chance of having a TIA. By lowering your risk of heart attack, you also reduce your chance of having a TIA. Age. Most TIAs occur after the age of 60. Family and medical history. If one of your family members has had a stroke or TIA or you have had a previous TIA, you are more likely to have a stroke or TIA.
Excessive somnolence This symptom may indicate bilateral hemispheric or brainstem involvement. Agitation or psychosis Rarely, these symptoms may indicate brainstem ischemia, particularly if they occur in association with cranial nerve or motor dysfunction. Confusion or memory changes These rarely are isolated symptoms; more frequently, they are associated with language, motor, sensory, or visual changes. Inattention to surrounding environment, particularly to one side; if severe, patient may deny deficit or even his or her own body parts. Depending on the severity of neglect, the physician may need to lift the patient's arm to check for strength, rather than rely on the patient to perform this task.
Diagnosis The doctor will ask about your symptoms and medial history, and perform a physical exam. A primary goal is to determine your stroke risk. Tests may include: Blood Tests - including a complete blood count, blood sugar, cholesterol, fat levels, clotting levels, and a check of other elements in the blood Electrocardiogram (EKG) – to measure heart rhythm and check for an irregular heart beat
Ultrasound – a test that uses sound waves to help determine if there are blockages in the arteries supplying the brain MRI Scan – a test that uses magnetic waves to make pictures of structures inside the head CT Scan – a type of x-ray that uses a computer to make pictures of structures inside the head Magnetic Resonance Angiography – performed prior to carotid artery surgery to determine how much the artery has narrowed. Gadolinium, a type of dye, may be injected into your vein for this test.
Arteriogram - during a conventional arteriogram, a contrast dye is injected and x-ray images are produced to precisely locate the blockage and to determine how much of the artery is blocked. This test is usually only done to confirm the need for surgery. Echocardiogram - an ultrasound test that looks for blood clots and valve abnormalities within the heart Electroencephalogram (EEG) - a test that can detect seizures by measuring brain waves (used only if a seizure is suspected) Occupational Therapist Rehabilitation after an injury may help some patients regain lost functions or learn new ways of accomplishing everyday tasks.