Extreme Delta Brush in Anti N-Methyl-D-Aspartate Encephalitis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) antibody-mediated encephalitis presents in young females with psychiatric disturbances, dyskinesias, and seizures. Prompt recognition and treatment can prevent morbidity and mortality. Antibody testing is not available readily in all parts of the world. Even if testing is available, report comes after 3–4 days, so a precious time window for treatment is lost. During this time, electroencephalogram (EEG) may help in diagnosis. A 21-year-old female presented to us with abnormal behavior, excessive laughing, and change in dressing habits for 2-week duration; generalized tonic–clonic seizures 2 episodes in the last 10 days; and not responding to external stimuli for 2 days. On examination, her vitals were stable, and she was in comatose state and extending her limbs to painful stimulus. She had perioral dyskinesias and bilateral extensor planters. Her hemogram, renal function test, and liver function tests were normal. Her contrast-enhanced magnetic resonance imaging brain was normal; cerebrospinal fluid examination showed mild pleocytosis. EEG was done which showed “extreme delta brush” pattern