Cerebrospinal fluid free N-acetyl neuraminic acid levels--a diagnostic and prognostic test in meningitis.

Cerebrospinal fluid (CSF) free N-acetyl neuraminic acid (NANA) levels were estimated in 20 cases each of pyogenic and tubercular meningitis (TBM) and 10 controls. The levels of free NANA were significantly high (P less than 0.001) in pyogenic and partially treated pyogenic meningitis when compared to TBM. The CSF free NANA levels had direct correlation with severity of the disease, CSF sugar and protein levels in pyogenic meningitis. The CSF free NANA can even be a prognostic criterion in management of pyogenic meningitis. Higher the levels, poorer the prognosis.