Behavioural disturbances following Japanese B encephalitis

Clinically, Japanese B encephalitis (JBE) is often overlooked as its occurrence in Western countries is rare. However, its neurological, cognitive and psychiatric sequelae constitute a major public health problem in the Far East where JBE is endemic. European and American subjects may however experience the JBE when returning from a Far East journey. In such cases, misdiagnosis is frequent because of the unawareness of psychiatrists and physicians. The present review, therefore, documents the behavioural and cognitive sequelae of JBE. This reactivates the debate concerning the vaccination against the virus all the more that the literature enlightens the importance of the vaccination for those who undertake frequent and extensive tourist excursions to the Orient but still discusses it for occasional travellers. Following is a case-report of a young western European post-graduate student who has contracted JBE by experiencing an acute febrile delirium during an unusual short stay in South East Asia. Pyramidal syndrome, Parkinsonism and amnesia were the prominent acute deficits. Whereas these faded in great part during convalescence, emotional and behavioural instability associated with affective involvement, obsessive-compulsive symptoms and cognitive impairments appeared. A partial recovery was however obtained with neuroleptics, lithium and following electro-convulsive therapy. Organic personality syndrome was persistent and thereafter constituted the main sequelae syndrome. Hypersomnia and several enuretic episodes persisted.