Contemporary encephalitis lethargica presenting with agitated catatonia, stereotypy, and dystonia‐parkinsonism

Encephalitis lethargica (EL) syndrome was classically described by Von Economo and has somnolent-ophthalmoplegic, hyperkinetic, and amyostatic-akinetic forms. We describe 2 recent cases of EL characterized by an acute encephalitis with mixed movement disorders (dystonia-Parkinsonism plus stereotypy) and psychiatric disorders (agitated catatonia, coprolalia, and echo phenomena). Both patients suffered concurrent hyperkinetic and Parkinsonian features resulting in therapeutic challenges. Bradykinetic features responded to dopamine replacement therapy and both patients also had adverse affects to dopamine antagonists (oculogyric crises plus neuroleptic malignant syndrome). Investigation was unremarkable other than the presence of CSF lymphocytosis and oligoclonal bands. Despite prolonged in-patient stays and intensive care management, both patients have made complete recoveries. We believe these cases support the hypothesis that this syndrome is an inflammatory encephalitis that specifically effects dopamine neurotransmission.