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48 Cards in this Set
- Front
- Back
Definition and causes of Cerebral Infarction- Carotid Circulation
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Thrombotic or embolic occlusion of a major vessel in the carotid circulation. Disorders predisposing to TIA and atheroscelrosis.
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Oclussion of what arteries is common in Cerebral Infarction - Carotid Circulation?
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• Opthalmic artery
• Anterior cerebral artery • Anterior communicating artery • Middle cerebral artery |
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Oclussion of what arteries is common in Cerebral Infarction- Vertebrobasilar Circulation
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• Posterior cerebral artery
• Vertebral artery • Posterior inferior cerebellar artery • Basilar Artery |
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Gold Standard for cerebral infarction?
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• CT scan of head
• Follow with diffusion-weighted MRI to define distribution and extent of infarction |
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Tx of cerebral infarction?
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1) 1st line: Aspirin
2) IV thrombolytic therapy with recominant tissue plasminogen activator (rtPA) effective in reducing neurologic deficit when administered ASAP 3) Heparin |
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Definition and causes of Cerebral Infarction- Carotid Circulation
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Thrombotic or embolic occlusion of a major vessel in the vertebrobasilar circulation. Disorders predisposing to TIA and atheroscelrosis.
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S/S of Cerebral (carotid) infarction?
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1) Anterior communication artery: weakness and cortical sensory loss in contralateral leg or arm.
2) Opthalmic artery: amaurosis fugax (sudden adn brief loss of vision) 3) Middle Communicating artery: |
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Definition of Cerebral hemorrhage- Arteriovenous malformation?
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Congenital vascular malformations that result from a localized maldevelopment of part of the vascular plexus.
* Results in ruptured aneurysm in subarachnoid space if intravascular pressure increases high enough |
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Clinical Presentation of arteriovenous malformation?
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Supratentorial lesions:
* HA (sometimes similar to migraine) * Seizure * Bruit over ipsilateral eye or mastoid region: (-) bruit does’t rule out AVM Infratentorial: * Usually clinically silent |
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Two regions of arteriovenous malformation?
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Supratentorial: Most common
Usually ruptures before age 40 Infratentorial: brainstem |
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Preferred imaging for AVM?
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* CT
* Angiography demonstrates vessels |
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Tx of AVM?
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* Surgery if AVM has bled
* If not, prevent further progression of neurologic deficit |
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Intracerebral hemorrhage - definition
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Subtype of intracranial hemorrhage that occurs within the brain tissue itself. Microaneurysms develop on perforating vessels in HTN pts
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Intracerebral hemorrhage - common sites/causes
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* MC in basal ganglia
* MC from trauma or ruptured aneurysm |
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Three common risk factors of intracerebral hemorrhage?
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1) Hypertension (especially non-traumatic)
2) Bleeding disorders (sickle cell, cumaden, clotting disorders) 3) Amyloid angiopathy (in elderly) |
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General Clinical Presentation of intracerebral hemorrhage?
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* Consciousness initially lost or impaired in about ½ of pts
* Vomiting/Headache * Focal neuro symptoms by site * Hemiplesia/hemiparesis or Hemisensory disturbance w/ deeply placed lesions * meningeal irritation - nuchal rigidity |
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Preferred imaging in intercerebral hemorrhage?
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* Non-contrast CT superior to MRI
* Angiography may be indicated to exclude aneurysm or AVM |
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What is contraindicated in intercerebral hemorrhage?
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Lumbar puncture; may cause herniation
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Cerebral infarction (Anterior Communicating artery) - presentation
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* causes weakness and cortical sensory loss in the contralateral leg and sometimes mild weakness of the arm, especially proximally.
* Bilateral anterior cerebral infarction is especially likely to cause marked behavioral changes and memory disturbances. |
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Cerebral infarction (middle cerebral artery) - presentation
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* contralateral hemiplegia, hemisensory loss
* homonymous hemianopia (ie, bilaterally symmetric loss of vision in half of the visual fields) * eyes deviated to the side of the lesion. |
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Cerebral infarction (posterior cerebral artery) - presentation
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may lead to a thalamic syndrome in which contralateral hemisensory disturbance occurs, followed by the development of spontaneous pain and hyperpathia.
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Cerebral Infarction - Tx
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* IV thrombolytic therapy with recominant tissue plasminogen activator (rtPA)
* Elevated intracranial pressure is managed by head elevation and osmotic agents such as mannitol. |
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Cerebral Infarction - Tx * Caution w/ pts during the acute (<2wks)?
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* Attempts to lower the blood pressure of hypertensive pts of a stroke should generally be avoided
* loss of cerebral autoregulation, and lowering the blood pressure may compromise ischemic areas. |
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Intracranial aneurysm - definition
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* Cerebrovascular disorder in which weakness of the walls of a cerebral artery casues ballooning
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MC location of an intracranial aneurysm?
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anterior circle of willis
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Saccular aneurysms, “berry type" - definition
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* tend to occur at arterial bifurcations, are frequently multiple (20% of cases), and are usually asymptomatic.
* associated with polycystic kidney disease and coarctation of the aorta. |
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higher risk of subarachnoid hemorrhage is associated with?
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older age, female sex, “non-white” ethnicity, hypertension, tobacco smoking, high alcohol consumption
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S/S of aneurysms?
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* focal neurologic deficit by compressing adjacent structures. However, most are asymptomatic or produce only nonspecific symptoms until they rupture
* Could have sudden severe headache * Nausea/Vomiting/Vision impairment/LOC |
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Tx for aneurysm?
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* Prevent further bleeding by clipping aneurysm or coil embolization
* Ctrl HTN (do not lower diastolic below 100mmHg), * Phenytoin (anti-siezure), Nimodipine (prevent vasospasm) |
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MC cause of subarachnoid hemorrhage?
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Trauma.
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MC cause of non-traumatic subarachnoid hemorrhage?
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usually rupture of “berry” aneurysm or AVM
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Risk factors of subarachnoid hemorrhage?
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• Smoking
• Hypertension • Hypercholesterolemia |
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Presentation of a subarachnoid hemorrhage?
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* Sudden onset of the "worst HA of my life"
* Sever N/V leading too LOC * Signs of meningeal irritation usually present, after a few hrs |
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subarrachnoid hemorrhage HA is caused by?
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* Herald bleed or “warning leak” causing focal deficits my be present but not always. The “sentinel HA”
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Preferred imaging for a subarrachnoid hemorrhage?
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* CT (preferably w/ CT angiography) to confirm diagnosis <24 hrs
* >48hrs use MRI * CT negative and suspicion high, perform lumbar puncture for RBC/high opening pressure |
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Tx for a subarachnoid hemorrhage?
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* clipping aneurysm or coil embolization
* Ctrl HTN * Phenytoin to ctrl seizure * Manitol to reduce bleeding * Nimopidine prevent vasospasm |
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Lacunar Infarction - definition
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Small lesions that occur in distribution of short penetrating arterioles in the deeper parts of the brain
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Lacunar infarction - etiology
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• Affects the basal ganglia, pons, cerebellum, internal capsule
• Neurologic deficit may progress over 24-36 hrs before stabilizing |
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4 characterics syndromes of lacunar infarctions?
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1. Pure sensory stroke (more common)
2. Pure motor hemiplegia- with internal capsule infarction 3. Ipsilateral ataxia w/ leg paresis 4. Dysarthria w/ clumsiness of hand |
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Diagnostic findings for lacunar infarction?
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• CT as small, punched-out, hypodense areas
• Diffusion-weighted MRI sensitive to acute lesions |
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Tx of lacunar infarction?
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* usually partial or complete resolution occurring over 4-6 weeks in many instances
* 1st line of tx: Aspirin and blood thinners (prines) * Longterm- control risk factors (HTN, DM) |
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Transient Ischemic Attack (TIA) - definition
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stroke-like symptoms that last less than 24 hrs, then symptoms resolve completely
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carotid circulation pts with a TIA may have?
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* Hand-arm weakness w/ sensory loss,
* Ipsilateral visual symptoms or aphasia * Amaurosis fugax. * possible bruit |
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Vertebrovascular TIA pt's may present w/?
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* Diplopia * Ataxia * Vertigo * Dysarthria
* Cranial nerve palsies * LE weakness * Perioral numbness * Drop attacks |
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Tx for non-cardiogenic TIA?
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Prophylactic antiplatelet (aspirin, ticlopidine, etc.)
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Tx for Cardiogenic TIA?
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• Anticoagulation therapy
• Initially IV heparin for those admitted to hospital • Warfarin for long-term tx |
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Arteriovenous malformation - definition
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Congenital vascular malformations that result from a localized maldevelopment of part of the vascular plexus
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Arteriovenous malformation may lead to what more severe Dx?
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ruptured aneurysm in subarachnoid space if intravascular pressure increases high enough
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