[Acute aseptic meningitis in adults. Retrospective study of 32 cases]

Abstract

Objective: The objective of this study was to analyze the characteristics of a series of acute aseptic meningitis (AAM) (defined by sterile cerebrospinal fluid (CSF) with more than 10 leucocytes per mm3 and a neutrophilic polynuclear-rich formula). We analysed the initial management, the reasons for antibiotic and/or antiviral treatment, the aetiologies, the need for lumbar puncture and the progression...

Method: We retrospectively analyzed 32 cases of AAM (out of a total of 130 cases of meningitis) from two departments of internal medicine in Lyon, diagnosed between January 1996 and January 2003. Only the files fulfilling the AAM criteria were retained, selecting those with a minimum neutrophilic polynuclear level of 30% in the CSF.

Results: The mean age was 32.6 years (range: 18-75) and predominantly male patients (59%). On admission, 87% of the patients exhibited fever, but only 9% remaining so for 72 hours. Viral syndrome before admission was noted in 59% of cases, with seasonal predilection (summer: 39%, winter: 35%). The motivation for lumbar puncture (LP) was meningeal syndrome (44%), headache (94%) and vomiting (47%). The average rate of neutrophils in the CSF on admission was 63% (range: 30-96). A control LP on Day 3 was performed 16 times (50%): mean PNN rate at 18% (range: 0-80), lymphocyte rate=68% (range: 20-95). Most of the patients (77.4%) had a C reactive protein (CRP) lower than 50 mg/l on admission (range: 5-320). A cerebral scan was performed 10 times (31%) and was abnormal 2 times (multiple cerebral abscesses, possible intracranial hypertension). An antibiotic (84%) and/or antiviral (34%) treatment was initiated. The evolution on Day 3 was favourable (87.5%): no fever, regression of the meningeal syndrome, with a mean duration of hospitalisation of 8.3 days (range: 1-60). Search for Herpes simplex virus and Enterovirus was made with PCR analysis in 20 cases (62.5%): no positivity for the herpes, but 9 for the Enterovirus. The systematic blood cultures were positive only once (staphylococcal infective endocarditis with cerebral abscesses). The diagnosis of bacterial meningitis was evoked 3 times (prior antibiotic treatment).

Discussion: The frequency of Enterovirus AAM should encourage this type of investigation in order to withdraw the often initiated anti-infectious treatment rapidly, and hence avoid a second lumbar puncture.