Introduction: Japanese encephalitis (JE) is a common mosquito borne viral encephalitis. Most infections of JE are asymptomatic but if clinical illness develops, it causes significant morbidity and mortality.

Aims and Objectives: To assess the serum electrolytes (Na⁺ and K⁺) in diagnosed cases of Japanese Encephalitis.

Materials and Methods: The study was carried out in Gauhati Medical College and Hospital, Guwahati, India between January, 2014 and July, 2015. Serum sodium and potassium levels in 100 diagnosed patients of Japanese Encephalitis was assayed in Vitros 5600 Analyser of Ortho Clinical Laboratories by the slide method that uses direct potentiometry for analysis of the ions. Equal number of age and sex matched healthy individuals were taken as control group.

Results and Observations: The present study shows that there is highly significant decrease in the serum sodium levels in the study group as compared to the control group (**p<0.001).On the other hand, there is no significant difference in potassium levels between the study group and the control group (p>0.05).

Discussion: There is highly significant decrease in the values of serum sodium levels in cases of Japanese Encephalitis, which may occur as a consequence of SIADH.

The findings of the present study thus have an impact in the treatment protocol, as hyponatremia impairs cerebrovascular reactivity. Maintenance of serum sodium level at the ideal level will lead to a significant decrease in both mortality and morbidity.

Keywords: Hyponatremia, Japanese Encephalitis, Serum potassium, Serum sodium.

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Dr Mousumi Borgohain Borah

Assistant Professor, Department of Biochemistry,

Gauhati Medical College & Hospital, Guwahati