New horizons (Baltimore, Md.)
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Frequent or continuous monitoring of crucial variables in patients with cerebrovascular disease allows the intensive care team to identify progression of the pathophysiologic mechanisms involved, intervene to halt or reverse this progression, and identify the response to treatment in order to modify the intervention if necessary. Central nervous system physiologic monitoring modalities include: a) the clinically-apparent function, b) physical and mechanical variables, c) circulation or perfusion, d) bioelectrical measures, and e) biochemical measures. The neurologic examination of the critically ill patient is an indispensable monitoring tool in the ICU. ⋯ Neurophysiologic monitoring with electroencephalography (EEG) and evoked potential (EP) testing can be used as a supplement to the neurologic exam and other diagnostic studies. EEG and EP can provide an early indication of clinically relevant change due to evolving disease or in response to therapy, which is especially helpful when the neurologic examination is limited due to severe coma, therapeutic barbiturate coma, or neuromuscular blockade. Neurometabolic monitoring in cerebrovascular disease with microdialysis is a promising technique that may be able to identify markers of cellular energy state or excitotoxicity in carefully selected areas of the brain.
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The prognostic features and outcomes associated with aneurysmal subarachnoid hemorrhage (SAH) are reviewed. In the first section, the epidemiology of SAH is discussed with emphasis on prevalence, incidence, risk factors, heredity, activity, and seasonal variability. ⋯ Also in the third section, the prognostic features associated with unruptured aneurysms are discussed with emphasis on the actuarial risk of rupture, aneurysm size and location, and multiplicity of lesions. In the fourth and final section, the outcomes of aneurysmal SAH over the past 60 yrs are reviewed.