Neuropsychiatric Manifestations of Autoimmune Encephalitis in a Tertiary Hospital: A Case Series and Current Perspectives.

Importance: Autoimmune encephalitis (AE) refers to a group of neuropsychiatric conditions associated with specific circulating autoantibodies directed against synaptic receptors, neuronal cell surface proteins, and intracellular targets. Increased recognition of these disorders is of value, as affected patients prominently display cognitive impairment, behavioral disturbances, and seizures requiring multidisciplinary teams, with early recognition often impacting prognosis. Observations: This case series is based on a retrospective record review of adult patients diagnosed with AE between January 1, 2010- January 1, 2020. Cases 1 and 2, demonstrating anti- N-methyl-d-aspartate receptor (NMDAR) encephalitis with initial manifestations of neurologic and psychiatric symptoms, correlate with the literature describing a higher prevalence of this condition in young women. Case 3, despite being seronegative, exhibited classic features of anti-NMDAR encephalitis. Case 4 demonstrates a classic presentation of anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis: a middle-aged male with psychosis, altered mentation, and epilepsy. Case 5 had a more indolent neuropsychiatric presentation with mild elevation of N-type voltage-gated potassium channel (VGKC) antibody. Case 6, with glutamic acid decarboxylase 65 (GAD65) antibody, was an elderly female with speech dysfunction and altered mentation, and case 7 was an elderly male with GAD65 antibody who had stiff-person syndrome, ataxia, cognitive decline, and thymoma. Conclusions: This retrospective case series describes the clinical details of 7 individuals with AE and overlapping neuropsychiatric symptoms. This series is limited in scope, with a small number of cases and observational findings, which prevents specific conclusions from being drawn. Despite this limitation, the present article explores the nuances of variable presentations of this disease to inform better interdisciplinary management and emphasize the gap areas that need rigorous research.