Ictal Rhythmic Alpha Sinusoidal Waves in 3 Cases of Anti-NMDAR Encephalitis

Previous studies have shown that extreme delta brush and high beta/delta power ratio on electroencephalogram are suggestive of anti- N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. Here we report 3 anti-NMDAR encephalitis patients with ictal rhythmic alpha sinusoidal waves in temporal regions, which suggested electrographic seizures in anti-NMDAR encephalitis and indicated potential for seizure occurrence in the future. Rhythmic alpha sinusoidal waves may be an electrographic feature and helpful in distinguishing anti-NMDAR encephalitis. In addition, extreme delta brush was also observed at 47-50 days after morbidity in 2 of 3 patients.