Encephalitis lethargica, first described in 1917 as a sequela of the Spanish flu, was characterized by a nonspecific inflammatory prodrome followed by profound sleep disturbances and chronic neurological sequelae, particularly postencephalitic Parkinsonism. Though numerous theories have been suggested to explain encephalitis lethargica, the rarity of the condition has limited formal investigations. Described here may be the first case of encephalitis lethargica in which the neuropsychiatric symptoms were successfully treated with electroconvulsive therapy. A middle-aged male, who initially presented with heterophonic palilalia following a protracted hospitalization for COVID-19 encephalitis 3 months prior, was admitted to inpatient psychiatry for a recurrence of palilalia. He rapidly deteriorated, developing extraocular ophthalmoplegia, persistent insomnia, severe intermittent tachypnea, acute Parkinsonism, and eventual akinetic mutism. He met the criteria described by Howard and Lee for encephalitis lethargica, with a presentation most consistent with the amyostatic-akinetic subtype. He failed pharmacological management but showed a marked improvement following 4 treatments with ultrabrief pulse right unilateral electroconvulsive therapy. Since discharge, his symptomatology has been controlled with 2 years of maintenance treatment.
Bonomo et al. (Tue,) studied this question.