Screening for anti-NMDAR encephalitis in psychiatry

Area of Science:

• Neurology
• Psychiatry
• Immunology

Background:

• Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis often initially presents with psychiatric symptoms.
• Timely diagnosis is essential for effective management and improved patient outcomes.

Purpose of the Study:

• To validate two proposed screening criteria for identifying patients with first episode psychosis who warrant anti-NMDAR antibody testing.
• To assess the diagnostic performance of these criteria in real-world clinical settings.

Main Methods:

• Retrospective analysis of published anti-NMDAR encephalitis cases and a state-wide cohort from Queensland, Australia.
• Evaluation of screening criteria performance using sensitivity, specificity, and AUC analysis.
• Assessment of criteria accuracy with and without neurological variables, and in non-psychotic cases.

Main Results:

• Both Scott et al. 'screening recommended' (AUC 0.914) and Herken and Pruss 'yellow flags' (AUC 0.875) criteria demonstrated high performance.
• These criteria maintained accuracy even when neurological variables were excluded or in cases without psychosis.
• The 'screening not recommended' and 'red flags' criteria showed limited clinical utility for screening.

Conclusions:

• Validated screening criteria can effectively identify patients with an atypical psychiatric presentation suggestive of anti-NMDAR encephalitis.
• Incorporating these criteria into routine psychiatric assessments may aid in early detection prior to overt neurological symptoms.
• The Scott et al. and Herken and Pruss criteria offer valuable tools for improving the diagnostic pathway for anti-NMDAR encephalitis.