Anti-NMDAR Encephalitis With Serial Negative MRI Findings: An Evaluation Using Autoimmune Psychosis Criteria.

Area of Science:

• Neurology
• Psychiatry
• Immunology

Background:

• Autoimmune encephalitis, particularly anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, can present with severe psychiatric symptoms.
• Diagnostic challenges arise due to overlapping symptoms with primary psychiatric disorders and sometimes unremarkable initial investigations like MRI.
• Proposed autoimmune psychosis criteria offer an alternative diagnostic framework to biomarker-based approaches.

Observation:

• A 15-year-old male experienced sudden seizures and progressive psychiatric decline, including catatonia and cognitive deterioration.
• Initial brain MRI and CSF analyses were unremarkable, leading to a misdiagnosis of a psychiatric disorder.
• The patient exhibited features aligning with autoimmune psychosis criteria, prompting further investigation.

Findings:

• Oligoclonal bands (OCBs) and anti-NMDAR antibodies were detected in serum and CSF, confirming NMDAR encephalitis.
• The patient met several autoimmune psychosis criteria, such as subacute psychiatric onset, catatonia, and seizures.
• Treatment with repeated steroid pulse therapy led to significant clinical improvement.

Implications:

• Autoimmune psychosis criteria can be a valuable tool for diagnosing NMDAR encephalitis, especially when initial imaging is negative.
• Early application of these criteria may prevent misdiagnosis and delayed treatment of autoimmune encephalitis.
• This case highlights the importance of considering autoimmune etiologies in patients with severe, unexplained psychiatric and neurological symptoms.