Recovery from severe frontotemporal dysfunction at 3 years after N-methyl-d-aspartic acid (NMDA) receptor antibody encephalitis

Encephalitis associated with antibodies against N-methyl-d-aspartic acid (NMDA) receptor is characterized by severe memory deficits, decreased consciousness, epileptic seizures and movement disorders and occurs most commonly in young women. Recovery is mostly good but little is known about the disease course in patients whose treatment has been delayed severely. We present a 16-year-old girl with a 36-month follow-up. A single course of methylprednisolone attenuated some symptoms but severe and incapacitating frontotemporal syndrome remained. Second-line treatment with rituximab was initiated 12 months after the onset of symptoms. A surprising recovery occurred 18 months after treatment and 30 months after onset. Recovery in NMDA receptor antibody-associated encephalitis can be severely delayed and does not have to be linear. Whether delayed therapy contributed to recovery in this patient cannot be answered with certainty. Spontaneous recovery independent of therapy is possible, as it has been observed previously as late as 3 years after onset. Although serum antibodies disappeared with recovery in this patient, previous cases have shown serum antibodies to be unreliable markers of disease activity. Second-line treatment, especially with substances as well tolerated as rituximab, should at least be considered in NMDA receptor encephalitis with persistent neuropsychiatric syndromes after first-line therapy.