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CVA. Ischemic and Hemorrhagic. Pathophysiology. Stroke is a rapid development of focal neurologic deficit caused by a disruption of blood supply to the corresponding area of the brain. To be classified as a stroke the neurological deficits need to persist for at least 24 hours
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CVA • Ischemic and Hemorrhagic
Pathophysiology • Stroke is a rapid development of focal neurologic deficit caused by a disruption of blood supply to the corresponding area of the brain. • To be classified as a stroke the neurological deficits need to persist for at least 24 hours • A stroke is termed a transient ischemic attack (TIA) if less than 24 hours • TIA risk factor • A variety of focal deficits are possible • changes in consciousness • sensory, motor, language, cognitive, and perceptual impairments • motor deficits are characterized by paralysis (hemiplegia) or weakness (hemiparesis) typically on the side opposite of the lesion
Pathophysiology • Hemorrhagic • Rupture of a blood vessel with abnormal bleeding into extravascular area of brain • usually the result of rupture of cerebral vessel or trauma • Primary cerebral hemorrhage (non-traumatic spontaneous hemorrhage) usually occur in small blood vessels weakened by atherosclerosis which produces an aneurysm • Subarachnoid hemorrhage occurring from bleeding into the subarachnoid space typically from a saccular or berry aneurysm affecting large blood vessels. • Can be intracerebral which is bleeding within the brain or subarachnoid
Pathophysiology • Ischemic • Occlusion of a blood vessel from thrombus, embolism, or conditions that produce low systemic perfusion pressure • Cerebral thrombosis is a formation or developing clot within the cerebral arteries or their branches. • Thrombi can lead to ischemia or occlusion of an artery which could result in a cerebral infarctions or tissue death (atherothrombotic brain infarction [ABI]) • subtypes include • large artery, atherosclerosis, cardiogenic embolism, small vessel occlusive disease
Risk Factors • Major risk factors • heart disease • hypertension • diabetes • Risk factors such as diabetes mellitus, hyperlipidemia, cigarette smoking, and hypertension fail to distinguish between ischemic and hemorrhagic types of stroke. • Having a TIA is a risk factor for stroke with about 10% of people having a major stroke within 90 days
Specific Risk Factors • Ischemic stroke • Age: elderly over 80 • Race: from greatest to least risk • black > hispanic > white • Sex: More men than women except in the 35-44 age range • Family History: monozygotic twins • Hemorrhagic stroke • Age: elderly • Sex: no significant difference between men and women except during pregnancy and postpartum • Race/Ethnicity: Asians > African Americans > Hispanics/Native Americans > Whites • Genetics: Icelandic CAA and Dutch CCA
Early Warning Signs of Stroke • Sudden numbness or weakness of the face, arm, or leg especially on one side of the body • Sudden confusion, trouble speaking or understanding • Sudden trouble seeing in one or both eyes • Sudden trouble walking, dizziness, loss or balance or coordination • Sudden severe headaches with no know cause • Sudden nausea, fever or vomiting distinguished from a viral by the speed of onset (minutes or hours vs several days) • Brief loss of consciousness or a period of decreased consciousness (fainting, confusion, convulsions, or coma)
Signs and Symptoms • Clinical features of a hemorrhagic stroke include: • severe headache from increased intracranial pressure • progressive deterioration from continued bleeding • vomiting from increased intracranial pressure • neck stiffness from meningeal irritation • bilateral babinski signs from enlargement of hemorrhage beyond the blood vessel involved • coma from bilateral cerebral dysfunction or uncal herniation • greater arm and leg hemiparesis
Signs and Symptoms • Common presentation of a patient with ischemic type of stroke: • previous TIA • numbness and uncoordinated extremity movements • alert mental status but may struggle with generating words • mild hemiparesis • facial paralysis • mild headache • absence of severe hypertension • absence of Babinski sign • Positive for dorsiflexion of the great toe with fanning of the other toes on stimulation of the lateral plantar surface of the foot
How is the Patient Affected? • BOTH ischemic and hemorrhagic types of stroke may cause neurological deficits such as hemiparesis, hemisensory loss, aphasia, opthalmoplegia and visual field cuts • Hemorrhagic stroke may cause additional symptoms due to leakage of blood that displaces and compressing surrounding brain tissues
Special Tests • A TIA is a predictor of ischemic type stroke • The greatest risk of stroke is within 90 days after the TIA with half occurring within first 7 days. • All patients with a new stroke need to undergo a CT to distinguish between hemorrhagic and ischemic stroke • Babinki Test for ischemic or hemorrhagic • No findings or combination of findings suggest are definitive of either type of stroke • To rule in/out either type of stroke requires neuroimaging to be absolutely certain
References • Grysiewicz, Rebbeca A. et al. Epidemiology of Ischemic and Hemorrhagic Stroke: Incidence, Prevalence, Mortality, and Risk Factors. Neuro Clin (2008); 26: 871-895. • Khaw, Kay-Tee. Epidemiology of Stroke. Journal of Neurology, Neurosurgery and Psychiatry (1996); 61: 333-338. • Runchey, Shauna and McGee, Steven. Does This Patient Have Hemorrhagic Stroke? Clinical Findings Distinguishing Hemorrhagic Stroke from Ischemic Stroke. JAMA (2010); 303; 2280-2286.