[Sensitivity and specificity of clinical signs in adults]

Clinical diagnosis of acute bacterial meningitis may be delayed, either because off lack of sensitivity of clinical signs, or because of a poor vital prognosis; but over diagnosing is also frequent, leading to useless, expensive, and potentially dangerous hospitalizations. We conducted a comprehensive review of English and French literature from 1997 to 2007 by searching MEDLINE to review the accuracy of clinical examination for the diagnosis of meningitis. Additional references were identified by reviewing reference lists of articles back to 1993. We used the keywords "meningitis", "meningitis and clinical features", "cerebrospinal fluid (CSF) pleocytosis", "headache and fever", "Kernig sign", "Brudzinski sign", and "neck stiffness". We excluded nosocomial meningitis. Sensitivity for clinical signs such as headache, vomiting, or fever was low, generally less than 30%, neck stiffness could reach 45%, but the absence of two signs among fever, headache, neck stiffness, and altered mental status eliminated meningitis with a negative predictive value of 95%. Given the seriousness of bacterial meningitis, clinicians perform lumbar puncture (or brain imaging) too often, especially in high-risk patients. Further prospective clinical research is needed to improve the accuracy of bacterial meningitis clinical diagnosis.