Subarachinoid_Hemorrhage - Subarachinoid Hemorrhage...

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Unformatted text preview: Subarachinoid Hemorrhage Hemorrhage Etiologies of subarachnoid hemorrhage (SAH) hemorrhage trauma: the most common cause of SAH ruptured intracranial aneurysms: 75­80% of spontaneous SAHs cerebral AVMs: 4­5% of cases certain vasculitides that involve the CNS rarely due to tumor cerebral artery dissection (may also be post­ traumatic) no cause can be determined in 14­22% Risk factors for SAH hypertension cigarette smoking oral contraceptives alcohol consumption (debatable) diurnal variations in blood pressure pregnancy and parturition slight increased risk during lumbar puncture and/or cerebral angiography in patient with cerebral aneurysm slight increased risk with advancing age following cocaine abuse Conditions associated with aneurysms aneurysms . autosomal dominant polycystic kidney disease fibromuscular dysplasia (FMD): incidence of aneurysms in renal FMD is 7%, in aortocranial FMD 21% arteriovenous malformations (AVM) connective tissue disorders: Ehlers­Danlos type IV (deficient collagen type III), Marfan's syndrome, pseudoxanthoma elasticum multiple other family members with intracranial aneurysms coarctation of the aorta Clinical features Clinical Symptoms Sudden onset of severe H/A vomiting syncope (apoplexy) neck pain (meningismus) photophobia. Focal cranial nerve deficits may occur (especially third nerve, causing diplopia and/or ptosis). Low back pain may develop due to irritation of lumbar nerve roots by dependent blood. Hunt and Hess (H&H) classification of SAH 1 asymptomatic, or mild H/A and slight nuchal rigidity 2 Cr. N. palsy (e.g. III, VI), moderate to severe H/A, nuchal rigidity 3 mild focal deficit, lethargy, or confusion 4 stupor, moderate to severe hemiparesis, early decerebrate rigidity 5 deep coma, decerebrate rigidity, moribund appearance Add one grade for serious systemic disease (e.g. HTN, DM, severe atherosclerosis, COPD) or severe vasospasm on arteriography. Modified classification adds the following 0 unruptured 1a acute meningeal/brain reaction, but with fixed neuro deficit Evaluation Evaluation 1. tests to diagnose SAH tests 1. non-contrast high-resolution CT scan 1. 2. if CT is negative: LP in questionable cases if 2. cerebral angiography in confirmed cases or if high 2. cerebral degree of suspicion degree Lumbar puncture Lumbar The most sensitive test for SAH. LP findings: 1. opening pressure: elevated 2. appearance: ­non­clotting bloody fluid that does not clear with sequential tubes ­xanthochromia: yellow discoloration. Usually takes 1­2 days to develop 3. cell count: RBC count usually > 100,000 RBCs/mm3. Compare RBC count in first to last tube (should not drop significantly). For questionable case Initial management concerns concerns 1. 2. 3. 4. 5. 6. 7. rebleeding hydrocephalus delayed ischemic neurologic deficit (DIND), usually attributed to vasospasm. hyponatremia with hypovolemia DVT and pulmonary embolism seizures determining source of bleeding: 4­vessel cerebral angiography is required. Rebleeding Rebleeding Maximal frequency of rebleeding is in the 1st day ­ 4% on day 1 - then 1.5% daily for 13 d - 15­20% rebleed within 14 d, - 50% will rebleed within 6 months, - thereafter the risk is 3%/yr with a mortality rate of 2%/yr Rebleeding Rebleeding - - - In a study of 33 patients who rebled, the highest risk of rebleeding occurred in the first 6 hours following SAH. The rebleeding risk is higher in patients with a high Hunt and Hess grade. Risk did not appear to be altered by BP on admission or site of aneurysm. Treatment of aneurysm Treatment The best treatment for an aneurysm depends on the: ­condition of the patient ­the anatomy of the aneurysm ­the ability of the surgeon Timing of aneurysm surgery Timing Controversy exists between so­called "early surgery" (generally, but not precisely defined as < 48 hrs post SAH) and "late surgery" > 48 hrs (usually 10­14 days post SAH). Guglielmi detachable coil (GDC) coil Basilar tip aneurysm Basilar Vasospasm Vasospasm Unruptured Intracranial Aneurysm Aneurysm Unruptured intracranial aneurysms (UIA) includes: A­ incidental aneurysms B­aneurysms that produce symptoms other than those due to hemorrhage Estimated prevalence of UIA is 5­10% of population. ...
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This note was uploaded on 12/24/2011 for the course STEP 1 taught by Professor Dr.aslam during the Fall '11 term at Montgomery College.

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