Japanese encephalitis (JE) part II: 14 Years’ follow-up of survivors

Japanese encephalitis, the commonest Arbovirus encephalitis, has been endemic in many parts of Asia, the Pacific Islands, and India; also, there have been many epidemics. Most of the post JE cases have been associated with neurological and neuropsychiatric deficits but have not been properly classified and followed. Practically all the previous studies were in children or young adults. The aim of this study, involving only adult cases, the largest ever being reported, has been to follow the 688/1,199 survivors of JE patients out of 1,282 of acute cases admitted during four epidemics for a period of 14 years after properly classifying the sequelae. This prospective study was conducted in B.R.D. Medical College Gorakhpur (India), involving 665/688 post JE cases with neuropsychiatric deficits from four epidemics of 1978, 1980, 1988 and 1989 which were properly classified in nine groups. While the first epidemic of 1978 was being studied, more disastrous episodes flared up and the patients were subsequently added. Hence, the total duration of this prospective study was from November 1978 to December 2003. There were 14 defaulted initially from 688 followed (23/688 without sequelae and 665/688 with neuropsychiatric deficits), and later 130 were lost from time to time at various stages of follow up. Four out of 23/688 discharged without any deficit had to be readmitted for bizarre movements, assaultative behaviour and euphoria without fever and altered sensorium. All of them improved by symptomatic treatment. Progressive improvement occurred in all the parameters consisting of psychological disturbances, higher cerebral dysfunction, speech disorders (dysphonia, dysarthria, dysphasias, apraxia and agnosia), extra pyramidal, pyramidal features, and hypothalamic disturbances, cranial nerves including pupils and fundi and seizures. Maximum cases improved between 6 months (55%) to 1 year (78%). Only some features improved between 5 to 14 years. Four patients of hemiplegia remained bed ridden. Some non disabling features like dysarthria and corticospinal features without paralysis persisted in 5% (95% improved) and 74% (26% improved) respectively. One patient with bizarre movement and nine with marked tremors could not regain normalcy. A large number of patients of JE are left with several minor or gross residual neuropsychiatric and neurological features after the acute phase. In this series also the discharged patients with neurological deficits who were quite disabled initially and needed constant care by family members and also those who required some help intermittently improved with passage of time and eventually returned to normal life. Some of them were left with non-disabling residual neurological signs even after 14 years. Fourteen of 544 (3%) could not return to their livelihood.