Early identification of anti-NMDA receptor encephalitis presenting cerebral lesions in unconventional locations on magnetic resonance imaging.

To facilitate the diagnosis of anti-NMDAR encephalitis presenting with brain lesions in unconventional locations (BLUL) on MRI, we retrospectively analyzed forty-five Chinese patients. Eighteen (40.0%) of their MRI initially exhibited one or more BLUL. These locations predominantly included cerebral gray matter (cortex, basal ganglia and thalamus), as well as white matter and brainstem. Due to these BLUL, thirteen (72.2%) patients were originally misdiagnosed with other diseases and developed poor clinical and imaging outcomes. Therefore, anti-NMDAR encephalitis has unpredictable MRI findings that easily obscure its diagnosis and cause serious sequelae. Anti-NMDAR antibody tests are highly recommended in patients with BLUL.