Gombolay G, Brenton JN, Yang JH, Stredny CM, Kammeyer R, Fisher KS, Sandweiss AJ, Erickson TA, Kannan V, Otten C, Steriade C, Vu N, Santoro JD, Robles-Lopez K, Goodrich R, Otallah S, Arellano J, Christiana A, Morris M, Gorman MP, Kornbluh AB, Kahn I, Sepeta L, Jiang Y, Muscal E, Murray KO, Moodley M, and Hardy D
Background: Isolated psychiatric symptoms can be the initial symptom of pediatric anti-N-methyl-d-aspartate (NMDA) receptor autoimmune encephalitis (pNMDARE). Here we report on the prevalence of isolated psychiatric symptoms in pNMDARE. We also assess whether initial neurodiagnostic tests (brain magnetic resonance imaging [MRI], electroencephalography [EEG], and/or cerebrospinal fluid [CSF] white blood cell count) are abnormal in children with isolated psychiatric symptoms and pNMDARE., Methods: This multicenter retrospective cohort study from CONNECT (Conquering Neuroinflammation and Epilepsies Consortium) from 14 institutions included children under age 18 years who were diagnosed with pNMDARE. Descriptive statistics using means, medians, and comparisons for continuous versus discrete data was performed., Results: Of 249 children included, 12 (5%) had only psychiatric symptoms without other typical clinical features of autoimmune encephalitis at presentation. All but one (11 of 12 = 92%) had at least one abnormal finding on initial ancillary testing: eight of 12 (67%) had an abnormal EEG, six of 12 (50%) had an abnormal MRI, and five of 12 (42%) demonstrated CSF pleocytosis. The single patient with a normal MRI, EEG, and CSF profile had low positive CSF NMDA antibody (titer of 1:1), and symptoms improved without immunotherapy., Conclusions: Isolated first-episode psychiatric symptoms in pNMDARE are uncommon, and the majority of children will exhibit additional neurodiagnostic abnormalities. Delaying immunotherapy in a child with isolated psychiatric symptoms and normal neurodiagnostic testing may be warranted while awaiting confirmatory antibody testing., Competing Interests: Declaration of competing interest Dr. Gombolay receives an honorarium as a Media Editor for Pediatric Neurology. Dr. Brenton has received compensation for consulting for I-ACT for Children on a Novartis-sponsored project and Cycle Pharmaceuticals. Dr. Mark Gorman has been personally compensated for work on a medical advisory board for Arialys Therapeutics. Dr. Santoro receives consultation fees from Biogen, UCB, and Cycle Pharma on conditions unrelated to the data presented. The rest of the authors have no relevant conflicts of interest to report., (Copyright © 2024 Elsevier Inc. All rights reserved.)