Reversible brain atrophy in anti-NMDA receptor encephalitis: a long-term observational study

The long-term neuroimaging correlates of clinical recovery have not been described in anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. The aim of the study is to evaluate the long-term outcome of brain atrophy in anti-NMDAR encephalitis. Patients were two women (ages 17 and 33 years) with severe anti-NMDAR encephalitis resulting in decreased level of consciousness, autonomic instability, hypoventilation, and dyskinesias requiring continuous infusion of anesthetic agents for 6–7 months. Brain MRI and cerebral blood flow SPECT obtained at the time of maximal neurological disability were compared with similar studies obtained 5–7 years later. Both patients were hospitalized for 9–14 months and developed frontotemporal atrophy and hypoperfusion 7–12 months after symptom presentation. In both patients, cognitive functions gradually improved over the next 4–5 years. Comparative neuroimaging studies obtained 5–7 years after symptom presentation showed dramatic improvement of the atrophy and frontotemporal hypoperfusion. The severe and protracted deficits and the frontotemporal atrophy that occur in some patients with anti-NMDAR encephalitis are potentially reversible. This suggests that a functional rather than a structural neuronal damage underlies the pathogenesis of this disorder.