BACKGROUND: In adults with suspected @entity693 clinicians routinely order computed tomography (CT) of the head before performing a lumbar puncture. METHODS: We prospectively studied 301 adults with suspected @entity693 to determine whether clinical characteristics that were present before CT of the head was performed could be used to identify @entity1 who were unlikely to have abnormalities on CT. The Modified National Institutes of Health @entity64 Scale was used to identify @entity16 . RESULTS: Of the 301 @entity1 with suspected @entity693 , 235 (78 percent) underwent CT of the head before undergoing lumbar puncture. In 56 of the 235 @entity1 (24 percent), the results of CT were abnormal; 11 @entity1 (5 percent) had evidence of a mass effect. The clinical features at base line that were associated with an abnormal finding on CT of the head were an age of at least 60 years, immunocompromise, a history of @entity6220 , and a history of @entity410 within one week before presentation, as well as the following @entity16 : an abnormal level of consciousness, an inability to answer two consecutive questions correctly or to follow two consecutive commands, gaze @entity227 , @entity3541 , arm drift, leg drift, and abnormal language (e.g., @entity2026 ). None of these features were present at base line in 96 of the 235 @entity1 who underwent CT scanning of the head (41 percent). The CT scan was normal in 93 of these 96 @entity1 , yielding a negative predictive value of 97 percent. Of the three misclassified @entity1 , only one had a mild mass effect on CT, and all three subsequently underwent lumbar puncture, with no evidence of @entity75 one week later. CONCLUSIONS: In adults with suspected @entity693 , clinical features can be used to identify those who are unlikely to have abnormal findings on CT of the head.

Computed tomography of the head before lumbar puncture in adults with suspected XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity6220 :: ('MESH:D020279', 'Disease') :: ['central nervous system disease'] @entity64 :: ('MESH:D020521', 'Disease') :: ['Stroke'] @entity410 :: ('MESH:D012640', 'Disease') :: ['seizure'] @entity227 :: ('MESH:D014786', 'Disease') :: ['palsy, abnormal visual fields'] @entity75 :: ('MESH:D001927', 'Disease') :: ['brain herniation'] @entity16 :: ('MESH:D009422', 'Disease') :: ['neurologic abnormalities'] @entity693 :: ('MESH:D008581', 'Disease') :: ['meningitis'] @entity2026 :: ('MESH:D001037', 'Disease') :: ['aphasia'] @entity3541 :: ('MESH:D005158', 'Disease') :: ['facial palsy']
@entity693 :: (MESH:D008581,Disease) :: ['meningitis']
