Volume 6, Number 9;  July 19, 2006

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Unique Identifier [PMID]: 11742046

Author: Hasbun R, Abrahams J, Jekel J, Quagliarello VJ.

Institution: Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.

Title: Computed tomography of the head before lumbar puncture in adults with suspected meningitis.

Source: N Engl J Med. 2001 Dec 13;345(24):1727-33.

Abstract: BACKGROUND: In adults with suspected meningitis clinicians routinely order computed tomography (CT) of the head before performing a lumbar puncture. METHODS: We prospectively studied 301 adults with suspected meningitis to determine whether clinical characteristics that were present before CT of the head was performed could be used to identify patients who were unlikely to have abnormalities on CT. The Modified National Institutes of Health Stroke Scale was used to identify neurologic abnormalities. RESULTS: Of the 301 patients with suspected meningitis, 235 (78 percent) underwent CT of the head before undergoing lumbar puncture. In 56 of the 235 patients (24 percent), the results of CT were abnormal; 11 patients (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 central nervous system disease, and a history of seizure within one week before presentation, as well as the following neurologic abnormalities: an abnormal level of consciousness, an inability to answer two consecutive questions correctly or to follow two consecutive commands, gaze palsy, abnormal visual fields, facial palsy, arm drift, leg drift, and abnormal language (e.g., aphasia). None of these features were present at base line in 96 of the 235 patients who underwent CT scanning of the head (41 percent). The CT scan was normal in 93 of these 96 patients, yielding a negative predictive value of 97 percent. Of the three misclassified patients, only one had a mild mass effect on CT, and all three subsequently underwent lumbar puncture, with no evidence of brain herniation one week later. CONCLUSIONS: In adults with suspected meningitis, clinical features can be used to identify those who are unlikely to have abnormal findings on CT of the head.

Publication Types: Evaluation Studies

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Unique Identifier [PMID]: 10597758

Author: Gopal AK, Whitehouse JD, Simel DL, Corey GR.

Title: Cranial computed tomography before lumbar puncture: a prospective clinical evaluation.

Source: Arch Intern Med. 1999 Dec 13-27;159(22):2681-5.

Abstract: Department of Medicine, Duke University, Durham, NC, USA. agopal@u.washington.edu

OBJECTIVE: To prospectively identify which patients can safely undergo lumbar puncture (LP) without screening cranial computed tomography (CT). METHODS: Emergency department physicians examined patients before CT. Examiners recorded the presence or absence of 10 clinical findings and answered 8 additional questions. The criterion standard was noncontrast cranial CT interpreted by staff radiologists. Clinical findings were prospectively compared with those of CT. RESULTS: One hundred thirteen consecutive adults with the urgent need for LP (median age, 42 years) were studied. Fifteen percent of patients meeting entrance criteria had new CT-documented lesions, with 2.7% having lesions that contraindicated LP. Sensitivity, specificity, and likelihood ratios (LRs) were measured for the clinical findings. Three statistically significant predictors of new intracranial lesions were identified: altered mentation (positive LR, 2.2; 95% confidence interval [CI], 1.5-3.2), focal neurologic examination (positive LR, 4.3; 95% CI, 1.9-10), and papilledema (positive LR, 11.1; 95% CI, 1.1-115). No single item adequately predicted the absence of CT abnormalities, but the clinical screening items in aggregate significantly predicted the results (negative LR, 0; upper 95% confidence limit, 0.6). The overall clinical impression had the highest predictive value in identifying patients with CT-defined contraindications to LP (positive LR, 18.8; 95% CI, 4.8-43). CONCLUSIONS: Because of the low prevalence of lesions that contraindicate LP, screening cranial CT solely to establish the safety of performing an LP typically provides limited additional information. Physicians can use their overall clinical impression and 3 clinical predictors to identify patients with the greatest risk of having intracranial lesions that may contraindicate LP.

Publication Types: [None]

Resident Report / Department of Medicine & Grady Branch Library

Emory University School of Medicine

2006 Edition

Participating Faculty:  Carlos Del Rio MD  / Joyce Doyle MD / Lorenzo Difrancesco MD / Joel Mermis MD / Maunank Shah MD

Contact: Karl Woodworth