Background: Malaria remains a serious challenge with high morbidly and mortality in the developing countries despite of availability of advanced diagnostic and treatment facilities. Encephalitis too simulates cerebral malaria in presentation and severity. Most of the time, it is difficult clinically to diagnose individual entity to start the specific treatment.Several studies on cerebral malaria shows increase in cerebrospinal fluid(CSF) lactate being the sign of bad prognosis but a few studies are there to establish the role of CSF lactate level in viral Encephalitis.

Objective:To study the role of serum and CSF lactate In cerebral malaria and encephalitis and its prognostic significance.

Method:Out of 57 cases, 22 malaria and 35 viral encephalitis cases were identified clinically, by Rapid Diagnostic Test(RDT) and blood MP for malaria and serological tests for herpes simplex virus(HSV)1 and HSV2. Age and sex matched 25 control cases were included having no neurological disease who were to be operated for minor surgical ailments like hernia, hydrocoele, etc. under spinal anaesthesia .Blood samples and CSF were collected and subjected to serum lactate and CSF lactate estimation along with routine biochemical and cytological investigations and analysed.
Results:Serum lactate in cerebral malaria was significantly higher compared to viral encephalitis and control. MeanCSF lactate was significantly high in cerebral malaria compared to viral encephalitis and control. CSF lactatevalue is higher in nonsurvivors than survivors.Serum lactate in viral encephalitis and control did not show any significant difference, also no significant difference between survivor and non survivor.
Conclusion:Serum lactate is significantly high in cerebral malaria compared to viral encephalitis and it has prognostic significance.CSF lactate is significantly higher in encephalitis than cerebral malaria patients and it has prognostic value.