EEG IN JAPANESE ENCEPHALITIS - A CLINICORADIOLOGICAL CORRELATION

This study was undertaken due to the paucity of studies on electroence phalographic (EEG) changes in Japanese encephalitis (JE) and their cli nical and radiological correlation. Twenty seven patients with JE were included whose age ranged between 2 and 54 years, 8 of whom were fema les and 10 aged 12 or less. On admission, Glasgow coma scale (GCS) ran ged between 4 and 9. Seizures were present in 9 patients which were ge neralised tonic clonic in all except one who had partial motor seizure . Behavioural abnormalities were present in 3 patients. Three patterns of EEG were noted which included diffuse continuous delta in 21, diff use delta with spikes in 3; and nonmodulating non responsive alpha act ivity ('alpha pattern' coma) in 3 patients. The background EEG activit y became normal in all at 3 months although seizure activity was noted in 3 patients. MRI or/and CT scan revealed bilateral thalamic involve ment in all, pens in 2, midbrain in 7, basal ganglia in 5, cerebral co rtex in 4 and white matter oedema in 5 patients. Five patients died in the acute stage and 3 patients lost from followup. At 3 months, 7 pat ients had complete, 6 partial and 6 poor recovery. The EEG pattern did not correlate with the GCS and outcome. In JE, EEG reveals non-specif ic delta showing in acute stage and 'alpha pattern' coma may be a more common presentation than realised and does not always predict a poor outcome. (C) 1998 Elsevier Science Ireland Ltd.