Cerebrospinal fluid viscosity: a novel diagnostic measure for acute meningitis.

Introduction: Early diagnosis of acute meningitis has paramount importance in clinical practice because of mortality and morbidity of the disease. Examination of cerebrospinal fluid (CSF) has critical value for the diagnosis of acute meningitis and discrimination of bacterial and aseptic meningitis. It has been previously reported that plasma viscosity can be used as an inflammatory marker. In this study we aimed to evaluate the role of CSF viscosity as a complementary measure for diagnosis of meningitis in suspected patients.

Methods: Forty-one consecutive patients who underwent lumbar puncture to rule out meningitis were studied prospectively. Twenty-seven patients were diagnosed with meningitis, of whom 13 patients had aseptic meningitis and 14 patients had bacterial meningitis. Meningitis was ruled out in 14 patients.

Results: CSF protein and CSF viscosity were significantly higher in patients with meningitis compared to nonmeningitis. Receiver operator characteristic (ROC) analysis revealed that CSF viscosity was highly sensitive (100%) and specific (93%); measures for the diagnosis of meningitis in the study population was comparable to those of CSF protein. Additionally, patients with meningitis were also divided into two groups as having bacterial and aseptic meningitis. CSF viscosity also significantly differed between bacterial and aseptic meningitis.

Conclusion: The CSF viscosity is a simple and easy method and can be used as an adjunctive measure for the diagnosis of meningitis. With the support of further and larger clinical studies, CSF viscosity may have a role in the discrimination of bacterial versus aseptic meningitis.