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M6 13-005
Exam 15: Cerebrovascular Accident
Term | Definition |
---|---|
Cerebrovascular Accident (CVA) Also called Stroke or “Brain Attack”. | An abnormal condition of the blood vessels of the brain characterized occlusion by an embolus, thrombus or cerebrovascular hemorrhage or vasospasm, resulting in ischemia of the brain tissues, normally perfused by the damaged vessels. |
Cerebral Infarction | When blood flow is interrupted, oxygen deprivation of cerebral tissue precipitates rapid cerebral deterioration and tissue death, depending on time involved. |
Sequela of strokes is long term serious disabilities. | (1) Hemiparesis. (2) Inability to walk. (3) Aphasia. (4) Complete or partial dependence in ADLs. |
Strokes are classified as | ischemic or hemorrhagic. |
Ischemic strokes are | thrombotic and embolic. |
Most common thrombotic stroke is caused by | atherosclerosis |
thrombotic stroke risk factors | a) Use of oral contraceptives. b) Coagulation disorders. c) Polycythemia vera. d) Arteritis. e) Chronic hypoxia. f) Dehydration. |
Embolic stroke is | the second most common cause of stroke. |
Emboli most commonly originate | a thrombus in the endocardium |
thrombus in the endocardium cause by | Rheumatic heart disease, Mitral stenosis, Atrial Fibrillation, MI, valvular prostheses, infective endocarditis, and atrial septal defects. |
Most commonly embolus lodges in the | midcerebral artery. |
Hemorrhagic strokes are | intracerebral or intracranial in nature and cause damage by destroying and replacing brain tissue. |
Intracerebral | the bleeding into the brain tissue |
Intracranial | bleeding into the subarachnoid space.The third most common cause of strokes. |
Common causes of hemorrhagic strokes are: | 1) Hemorrhagic disease such as leukemia or aplastic anemia. 2) Severe hypertension. 3) Brain tumors. 4) Aneurysm |
Aneurysm | localized dilation of the wall of a blood vessel usually caused by atherosclerosis and hypertension. Aneurysm less often caused by trauma, infection or a congenital weakness in the vessel. |
Transient ischemic attack (TIA): | (1) An episode of cerebrovascular insufficiency with temporary episodes of neurological dysfunction that vary in severity. |
Most common deficit during TIA: | (a) Contralateral weakness of the lower face, hands, arms, and legs. (b) Transient dysphasia. (c) Numbness, loss of sensation. (d) Temporary loss of vision (one or both eyes). (e) Inability to speak. |
Manifestations of strokes: | Contralateral hemiplegia or paresis. Contralateral sensory loss. Spatial-perceptual deficits. Dysphasia or aphasia if dominant hemisphere is involved. Confusion and emotional lability. Impaired short term memory. Impaired left visual field. |
Noncontrast CT | the primary test to diagnose a stroke |
MRI is used to determine | extent of brain injury. |
Position Emission Tomography (PET) shows | the extent of tissue damage, by assessing brain’s metabolic activity. |
Cerebral angiography shows | displacement or blockage of blood vessels. |
Ultrasonography | indicate size of blood vessels and direction of blood flow |
A lumbar puncture may be performed to check for | blood in the CSF. (Only if ICP is normal) |
CVAs (Strokes) are considered a | medical emergency. |
Anticoagulation therapy is used in patients with | thrombolytic stroke |
Anticoagulation therapy is contraindicated in | hemorrhagic stroke |
Tissue Plasminogen activator (TPA) | if given with 3 hours of onset of ischemic CVA has been shown to have a 30% improvement in recovery limiting neurological deficits. |
Mechanical Embolus Removal in Cerebral Ischemia (MERCI) | Used to remove blood clots inside the brain |
Nimodipine (calcium channel blocker) is used for | prevention of vasospasm that occur 30% to 60% between postoperative days 4 and 12 of cases after aneurysm. |
Carotid endarterectomy (CEA) | surgical procedure that is performed to remove deposits of fat, called plaque, from the carotid arteries in the neck. |
Percutaneous transluminal angioplasty | procedure for enlarging a narrowed arterial lumen by peripheral introduction of a balloon-tip catheter followed by dilation of the lumen as the inflated catheter tip is withdrawn. |