A Clinical, Epidemiologic and Laboratory Investigation of Aseptic Meningitis during the Four-Year Period, 1955–1958

Meningitis With a Negative Cerebrospinal Fluid Gram Stain in Adults: Risk Classification for an Adverse Clinical Outcome

“…Many features of our cohort were similar to those in previous studies of meningitis and a negative Gram stain: the predominance of young adults, clinical features, CSF findings, and the high proportion of hospitalization, cranial imaging, and empirical antibiotic use. [2][3][4][5][12][13][14][15][16] However, there were several noteworthy observations in our study. First, the differential diagnosis of the meningitis causes was broad, and because a large proportion of the patients were immunosuppressed, one of the most commonly recognized urgent treatable causes was C neoformans.…”

“…Other large studies that have included patients with meningitis and a negative Gram stain have focused on describing the clinical epidemiology or developing and validating models to differentiate viral vs bacterial meningitis but have not evaluated patient outcomes. 2,3,5,[12][13][14][15][16] In our study, 3 clinically cogent and easily obtainable baseline variables (age Ͼ60 years, a CSF glucose level Ͻ45 mg/ dL, and abnormal neurologic examination findings) were used to derive and validate a model that classifies patients into low and high risk for an ACO. Our low- risk group had a 0.5% risk of an ACO and represented the majority of our cohort (64%).…”

“…A case was defined as an adult patient (age Ͼ16 y) with symptoms of community-acquired meningitis (fever, headache, stiff neck, altered mental status, or focal neurologic symptoms), a CSF leukocyte count greater than 5 cells/mm 3 (to convert to 10 9 /L, multiply by 1), and a negative CSF Gram stain who presented to an emergency department (ED) between January 1,2005 Data Collection, Laboratory Testing, and Definition of Diagnostic Outcomes Baseline patient characteristics were recorded at a specified "zero time," defined as the time when the patient was in the ED. Sociodemographic data, comorbid conditions (measured by the Charlson Comorbidity Index 6 ), immunocompetence, sick exposures, clinical features (including neurologic examination findings and Glasgow Coma Scale score 7 ), laboratory results, and management decisions were recorded.…”

“…2 In the 1950s, epidemiological studies of aseptic meningitis established a major role for viral etiologies, especially enteroviruses. 3 In the past 60 years, case reports have documented a wide array of infectious and noninfectious causes of meningitis because of an increasing immunosuppressed population, discovery of new infectious agents, and improvements in the field of diagnostic microbiology, virology, and neuroradiology. 4 Physicians recognize that patients with meningitis and a negative Gram stain may have etiologies that require urgent therapy, but they are uncertain of the probability for an adverse clinical outcome (ACO) in an individual patient.…”

Aseptic Meningitis Caused by Enteroviruses

“…Although most cases of enterovirus meningitis take a quite benign course, electroencepharograms may show slowing of the waves (Lepow et al, 1962). We investigated the electroencepharograms in several cases of enterovirus meningitis (Hayashi et al, 2009), but no cases revealed abnormal findings.…”