Evaluation of lactic dehydrogenase in cases of meningitis.

Lactic dehydrogenase (LDH) was measured serially in cerebrospinal fluid (CSF) and serum in 23 cases of meningitis (15 pyogenic and 8 tuberculous) and equal number of age and sex matched healthy controls to find out its diagnostic and prognostic significance in cases of meningitis. The LDH activity was significantly elevated in the CSF and serum (p < 0.001) in cases of pyogenic (PM) as well as tuberculous meningitis (TBM). The maximum elevation was seen on the 1st day and the activity declined thereafter. However, in 3 cases of PM and 5 cases of TBM, the LDH activity on subsequent estimations increased serially and all these cases died. Further, the basal LDH activity in the 3 cases of PM who died was significantly higher (p < 0.01) than those who survived. The rise in enzymatic activity in the CSF was significantly higher (p < 0.001) than in the serum in all the cases of meningitis. The LDH activity was significantly higher in PM as compared to TBM (p < 0.001) both in the CSF as well as the serum.

C-reactive protein in CNS infection.

Serum and CSF levels of CRP were measured by radial immunoassay in 99 subjects consisting of 20 controls, 34 pyogenic meningitis (PM), 21 tuberculous meningitis (TBM) and 24 viral encephalitis (VE). There was significant difference in the CRP levels (p less than 0.01) depending on the type of disease in both serum and CSF. The initial serum and CSF levels of CRP in patients with TBM was intermediate between those of PM and VE and were found to be significantly (p less than 0.001) low when compared with three days post treatment levels in children with PM. Both serum and CSF-CRP levels were significantly high (p less than 0.001) in patients succumbing to death than those who survived. Measurement of CRP in serum and CSF is a useful parameter in differentiating partially treated PM from TBM.