Recovery after Prolonged Disturbance of Consciousness and Repeated Cerebral Perfusion Changes in Neuronal Intranuclear Inclusion Disease

Encephalitic episodes are a clinical manifestation of neuronal intranuclear inclusion disease (NIID) and often show transient disturbance of consciousness. We herein report a genetically confirmed patient with NIID who initially presented progressive dementia and showed prolonged disturbance of consciousness pre-ceded by an acute-onset headache. During that time, we performed N-isopropyl-p-[123I] iodoamphetamine single-photon-emission computed tomography twice and found that the blood flow increased in different re-gions. Prolonged disturbance of consciousness following an encephalitic episode may be associated with re-peated hyperperfusion in various regions resulting from mitochondrial dysfunction. NIID patients presenting with encephalitic episodes can recover gradually and spontaneously even after prolonged disturbances of con-sciousness.