Abstract Details

Title CSF Pleocytosis in Encephalitis: A Multicenter Retrospective Study

Topic Autoimmune Neurology

Presentation(s) P5 - Poster Session 5 (5:30 PM-6:30 PM)

Poster/Presentation
Number 14-004

Objective The aim of this study is to compare the predictors, etiologies, and prognosis of patients with new-onset encephalitis who have normal levels of white blood cells in their initial cerebrospinal fluid (CSF) profile (<5 cells/µL), mild pleocytosis (5-50 cells/µL), and robust pleocytosis (>50 cells/µL).

Background

Early diagnosis of encephalitis involves identifying inflammatory signs in the central nervous system. However, the absence of CSF pleocytosis in encephalitis has been increasingly described. Understanding the predictors and outcomes associated with different CSF profiles can aid in the timely diagnosis and management of encephalitis.

Design/Methods

This retrospective study compares CSF profiles in 626 adult patients diagnosed with encephalitis, including those with all-cause encephalitis, infectious (IE), and autoimmune (AIE) subtypes.

Results Among 626 patients with encephalitis, 166 (26.5%) had normocellular CSF, 211 (33.7%) had mild, and 249 (39.8%) had robust pleocytosis. Out of 262 patients with IE, 88.5% of those with bacterial infections had robust pleocytosis, while those with viral and fungal infections had consistent distribution across the three levels of pleocytosis. IE patients with robust pleocytosis were more likely to receive acyclovir in <24hrs (normocellular 77.5%, vs. mild 89.5 p=0.18, and robust 91% p=0.024). Among 112 AIE patients, only 15 had robust pleocytosis, and 12 of those had anti-NMDAR encephalitis (p<0.001). None of the anti-LGI1/CASPR2 patients had robust pleocytosis, and 88.2% had normocellular CSF. No significant association was found between delays in initiation of appropriate immunotherapy and level of pleocytosis in patients with AIE. Finally, the level of pleocytosis was not associated with worse outcomes in either AIE or IE patients.

Conclusions

Pleocytosis is a criterion for encephalitis diagnosis, but 116 (26.5%) of our patients had normocellular CSF, among which 47 (28.3%) had IE. Thus, acyclovir initiation shouldn't be delayed in absence of pleocytosis. Robust pleocytosis could suggest the possibility of Anti-NMDAR encephalitis.

Authors/Disclosures
Ralph Habis, MD (Johns Hopkins School of Medicine) PRESENTER	Dr. Habis has nothing to disclose.
Anna Kolchinski, MD	Ms. Kolchinski has nothing to disclose.
Paris Bean	No disclosure on file
Ashley Heck	No disclosure on file
John Probasco, MD, FAAN (The Johns Hopkins Hospital)	Dr. Probasco has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for NEJM Clinician. The institution of Dr. Probasco has received research support from Roche/Genentech.
Rodrigo Hasbun	Rodrigo Hasbun has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Biomeriaux. The institution of Rodrigo Hasbun has received research support from Biomeriaux.
Arun Venkatesan, MD, PhD (Johns Hopkins Hospital)	Dr. Venkatesan has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Janssen Pharmaceuticals. The institution of Dr. Venkatesan has received research support from NIH. The institution of Dr. Venkatesan has received research support from U.S. DOD.

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