Longitudinal CSF Findings in Autoimmune Encephalitis-A Monocentric Cohort Study

Area of Science:

• Neurology
• Immunology
• Clinical Diagnostics

Background:

• Autoimmune encephalitis (AIE) presents with diverse symptoms, mimicking other neurological and psychiatric conditions, complicating diagnosis.
• Cerebrospinal fluid (CSF) analysis is crucial for differential diagnosis and identifying specific antibodies in AIE.
• Understanding CSF findings in antibody-associated AIE is essential for timely and accurate diagnosis.

Purpose of the Study:

• To describe initial and serial CSF findings in a cohort of 33 patients with antibody-associated AIE.
• To evaluate the utility of routine CSF parameters and oligoclonal bands (OCBs) in diagnosing and monitoring AIE.
• To explore the potential prognostic value of OCB status in anti-NMDAR AIE.

Main Methods:

• Monocentric cohort study analyzing CSF from 33 patients with confirmed antibody-associated AIE.
• Included analysis of routine CSF parameters (cell count, protein levels) and oligoclonal bands (OCBs).
• Serial CSF analyses were performed to track changes over time and correlate with clinical status.

Main Results:

• 12.1% of AIE patients had normal routine CSF parameters at diagnosis.
• Elevated protein levels (60.6%) and OCBs (45.4%) were common findings.
• Serial CSF analysis showed a trend toward normalization, with relapses linked to increased cells and protein; OCB conversion correlated with improvement in anti-NMDAR AIE.

Conclusions:

• A significant proportion of AIE patients may have normal CSF findings, potentially delaying diagnosis if antibody testing is not prioritized.
• OCB status in anti-NMDAR AIE patients may serve as a potential prognostic biomarker, warranting further investigation.
• Routine CSF analysis provides valuable diagnostic and monitoring information in AIE, but antibody identification remains critical.