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68 Cards in this Set
- Front
- Back
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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 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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Epidural hemorrhage (EDH) - definition
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is an easily treated form of head injury that is often associated with a good prognosis. In rare instances, such hemorrhages can be spontaneous. Advances in contemporary CT imaging have made confirmation of an EDH diagnosis rapid and accurate. Bleed is above the dura mater.
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EDH - epidemiology associated to trauma
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* 10-20% of all patients with head injuries are estimated to have EDH
* 17% of previously conscious patients who deteriorate into coma following a trauma have EDH. |
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Typical cause of EDH
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truama - mostly blunt
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Common injury site in traumatic EDH?
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Laceration of the middle meningeal artery and its accompanying dural sinuses
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Presentation/PE of EDH?
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* MOI
* classic lucid interval occurs in 20-50% of patients with EDH depending on MOI/force * Possible cushings triad (increase BP, chyane-stokes respirations, bradycardia) * Decreased GCS, AxO * Pos. pronator drift |
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Preferred imaging in EDH and associated findings?
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* CT
* Space occupied is limited by the adherence of the dura to the inner table of the skull * lenticular or biconvex appearance |
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Tx of EDH?
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* Primary Tx is evacuation of fluid
* Antihypertensive therapy during initial increased intracranial pressure may lead to critical cerebral ischemia and cell death * If a lesion is small and the patient is in good neurological condition, observing the patient with frequent neurological examinations is reasonable |
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Subdural bleed - definition
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collection of blood below the inner layer of the dura but external to the brain and arachnoid membrane. Subdural hematoma is the most common type of traumatic intracranial mass lesion
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MC type of intracranial mass lesion?
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Subdural bleed
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Subdural bleed is more common in?
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* men (acute/chronic)
* 5-25% of patients with severe head injury |
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Common causes of acute subdural bleeds?
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* Head trauma
* Coagulopathy or medical anticoagulation * cerebral aneurysm |
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Common causes of chronic subdural bleeds?
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* Head trauma (may be relatively mild, eg, in older individuals with cerebral atrophy)
* Acute subdural hematoma, with or without surgical intervention * Spontaneous or idiopathic |
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Common associated problems of subdural bleeds in younger pts?
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alcoholism, thrombocytopenia, coagulation disorders, and oral anticoagulant therapy have been found to be more prevalent.
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Common associated problems of subdural bleeds in older pts?
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cardiovascular disease and arterial hypertension are found to be more prevalent.
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Typical MOI in subdural bleeds?
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usual mechanism is a high-speed impact to the skull.
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Subdural hemorrhage - Presentation/PE (acute)
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* MOI
* A subset of patients remain conscious; others deteriorate in a delayed fashion as the hematoma expands. * Older pt more at risk |
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Definition difference between subacute and chronic hematomes?
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* Subacute subdural hematomas are defined arbitrarily as those that present between 4 and 21 days after injury.
* Chronic subdural hematomas are arbitrarily defined as those hematomas presenting 21 days or more after injury |
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S/S for chronic subdural hematoma?
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• Decreased level of consciousness
• Headache (MC, sudden onset, sever Px, N/V) • Difficulty with gait or balance • Cognitive dysfunction or memory loss (MC) • Personality change • Motor deficit (eg, hemiparesis) • Aphasia • May have presentation similar to Parkinson’s |
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Preferred imaging for subdural hematoma?
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* CT
* worsening of the Glasgow Coma Scale by 2 or more points should prompt repeat imaging in salvageable patients. |
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Subdural hematoma - Tx
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* prompt surgical evacuation of hematomas
* intensive care postoperatively for ventilator-dependent respiration, strict blood pressure control, and management of intracranial hypertension * In patients who have no significant mass effect on imaging studies and no neurologic symptoms or signs except mild headache, chronic subdural hematomas have been observed with serial scans and have been seen to remain stable or to resolve |
