The Neuropsychiatric Checklist for Autoimmune Psychosis: A Narrative Review

Autoimmune encephalitis (AE) is a rapidly evolving topic in both neurology and psychiatry. A recent international consensus article defined criteria for possible, probable, and definite autoimmune psychosis (AP) inspired by the principles established in neurology for the definition of AE. This has stimulated much clinical research on AP but also criticism of the validity of the criteria for possible AP, justifying additional clinical investigations such as lumbar puncture. In clinical practice, it is often difficult to decide how far diagnostic procedures such as lumbar punctures and immunotherapies should go in unclear cases. Against this background, we have 3 aims in this review. First, we summarize and compare the available concepts for the diagnosis of AP in a systematic literature review. Second, we present an overview of typical specific and nonspecific findings that can be obtained in laboratory, electroencephalography, magnetic resonance imaging, cerebrospinal fluid, and [¹⁸F]fluorodeoxyglucose positron emission tomography studies in the context of AP. Thirdly, we summarize these findings and present the Neuropsychiatric Checklist for Autoimmune Psychosis as a tool for clinical assessment of the likelihood of AP, with reference to the typical red-flag symptoms and the specific and many unspecific findings that can be identified in additional investigations. We suggest that this instrument may be a useful tool for a comprehensive, possibly uniform, and standardized case assessment in the context of possible AP.