The neurochemical markers in cerebrospinal fluid to differentiate between aseptic and tuberculous meningitis.

In this study, the use of neurochemical markers in patients with aseptic and tuberculous meningitis has been investigated. The cerebrospinal fluid levels of amino acids, nitrite (a metabolite of nitric oxide), vitamin B12 and homocysteine were quantitated in both groups of patients. Among the amino acids, aspartic acid and glutamic acid both excitatory amino acid, GABA, glycine and tryptophan were all significantly increased in both patient groups whereas decreased level of taurine and increased level of phenylalanine were only found in patients with tuberculous meningitis. The levels of nitrite and its precursor arginine were significantly higher in patients with tuberculous meningitis whereas unchanged levels were found in patients with aseptic meningitis. A significantly increased homocysteine level and a decreased level of vitamin B12 were found only in patients with tuberculous meningitis whereas unchanged levels were found in patients with aseptic meningitis. This indicates that patients with tuberculous meningitis are particularly prone to vitamin B12 deficiency resulting into increased level of HC, and involvement of free radical showing the importance of these biological markers for promoting the possibility for the design of therapeutic approach.