Recurrent Catatonia During Longitudinal Evaluation of Possible Seronegative Autoimmune Encephalitis: A Case Report.

Autoimmune encephalitis, primary psychiatric illness, seizure disorders, and catatonia can produce overlapping neuropsychiatric manifestations that complicate diagnosis and management, particularly when autoimmune encephalitis is suspected without detectable neuronal autoantibodies. We describe a woman in her early 20s with prior resection of a mature cystic ovarian teratoma and a reported clinical diagnosis of possible seronegative autoimmune encephalitis without documented serologic confirmation who experienced recurrent mania, psychosis, reduced oral intake, withdrawal, psychomotor slowing, and catatonic features across several hospitalizations in the context of a co-occurring seizure disorder. Her evaluations included neuroimaging, lumbar puncture, electroencephalography, evaluation for recurrent ovarian teratoma, and repeated neurologic consultation. Intravenous immunoglobulin was administered during one hospitalization because an autoimmune encephalitis relapse remained under consideration. Subsequent magnetic resonance imaging, pelvic imaging, and electroencephalography did not demonstrate objective evidence supporting active inflammatory recurrence. Catatonia became increasingly clinically actionable because symptoms repeatedly improved after lorazepam administration, prior malignant catatonia had responded to an extended course of electroconvulsive therapy, and lorazepam tapering was followed by recurrent psychiatric and catatonic deterioration with improvement after treatment was resumed. Although benzodiazepine responsiveness supported the clinical diagnosis of catatonia, it was interpreted within the broader clinical context and was not considered diagnostic in isolation. This case illustrates the value of longitudinal syndromic reassessment when etiologic certainty remains limited. Recognition and treatment of episodes clinically concerning for catatonia should not be delayed while autoimmune, seizure-related, medication-related, and primary psychiatric contributors continue to be evaluated.