Abstract Details

Title Sensitivity of Cell Count and Protein in Cerebrospinal Fluid for the Diagnosis of Autoimmune Encephalitis

Topic Autoimmune Neurology

Presentation(s) P2 - Poster Session 2 (5:30 PM-6:30 PM)

Poster/Presentation
Number 15-002

Objective To determine the sensitivity of elevated cerebrospinal fluid (CSF) cell count and protein for the diagnosis of autoimmune encephalitis.

Background The number of autoantibodies associated with definite autoimmune encephalitis have increased markedly over the past decade. However, delays in obtaining results mean that treatment decisions must be made before results return. Elevated CSF cell count and protein analysis may support the clinical diagnosis and inform early treatment decisions.

Design/Methods We retrospectively analysed the sensitivity of elevated CSF white cell count (>5cells/mm³)and protein (protein>450mg/dL) in patients with definite or antibody-negative but probable autoimmune encephalitis, as outlined in consensus clinical criteria (Graus et al. 2016).

Results 62 patients were diagnosed with autoimmune encephalitis since 2012 at the University Health Network (Toronto) Autoimmune Encephalitis Clinic. 47 patients had information available on a lumbar puncture obtained prior to receiving antibody testing results. The median time from symptom-onset to lumbar puncture was 50 days; 63% of lumbar punctures were performed within 90 days (range: 0-2034) from symptom-onset. The median time from admission to lumbar puncture was 4 days (range: 0-437); 82% of lumbar punctures were performed within 14 days from admission. All patients were symptomatic when CSF was obtained. The median (95% confidence interval [CI]) white cell count was 4 (2-8) cells/mm³and protein was 0.37 (0.31-0.55) mg/dL. Pleocytosis was present in 46.8% (95% CI: 25.9-67.7) and elevated protein was detected in 40.0% (95% CI: 17.1-62.9). White cells and protein were both elevated in 24.4% (95% CI: 6.7-42.1) of cases.

Conclusions The sensitivity of the combination of elevated CSF cell count and protein at presentation for detection of definite or probable autoimmune encephalitis is relatively low. Clinicians should use other ancillary tests and clinical judgement when making clinical decisions prior to receiving the results of autoantibody testing.

Authors/Disclosures
Julien Hebert, MD (Toronto Western Hospital (University Health Network)) PRESENTER	Dr. Hebert has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Paladin Labs. Dr. Hebert has received personal compensation in the range of $500-$4,999 for serving as an Expert Witness for Gowling WLG. The institution of Dr. Hebert has received research support from Praxis Precision Medicine.
Priti Gros, MD (University of Toronto)	Dr. Gros has nothing to disclose.
Sarah Lapointe, MD (CHUM)	Dr. Lapointe has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alexion.
Claude Steriade, MD (NYU)	The institution of Dr. Steriade has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for The Epilepsy Study Consortium. Dr. Steriade has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Dynamed. Dr. Steriade has received personal compensation in the range of $5,000-$9,999 for serving as an Expert Witness for DOJ. The institution of Dr. Steriade has received research support from NIH. Dr. Steriade has received personal compensation in the range of $500-$4,999 for serving as a Consultant with Epitel. Dr. Steriade has received personal compensation in the range of $500-$4,999 for serving as a Consultant with Jazz Pharmaceuticals. Dr. Steriade has received personal compensation in the range of $10,000-$49,999 for serving as a Speakers Bureau with SK Life Sciences. Dr. Steriade has received personal compensation in the range of $5,000-$9,999 for serving as a Speakers Bureau with Neurelis. Dr. Steriade has received personal compensation in the range of $5,000-$9,999 for serving as a Advisory Board with Xenon Pharmaceuticals.
Gregory S. Day, MD, MSc, FAAN (Mayo Clinic)	Dr. Day has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Arialys Therapeutics. Dr. Day has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for DynaMed (EBSCO Health). Dr. Day has or had stock in ANI Pharmaceuticals. The institution of Dr. Day has received research support from National Institutes of Health / NIA. The institution of Dr. Day has received research support from National Institutes of Health / NINDS. The institution of Dr. Day has received research support from Amgen Pharmaceuticals. The institution of Dr. Day has received research support from AVID Radiopharmaceuticals. Dr. Day has received personal compensation in the range of $500-$4,999 for serving as a Presenter at Annual Meeting (CME) with ��ɫ��. Dr. Day has received personal compensation in the range of $500-$4,999 for serving as a Content Development (CME) with PeerView, Inc. Dr. Day has received personal compensation in the range of $5,000-$9,999 for serving as a Content Development (CME) with Continuing ��ɫ��, Inc. Dr. Day has received personal compensation in the range of $5,000-$9,999 for serving as a Content Development (CME) with Ionis Pharmaceuticals. Dr. Day has received personal compensation in the range of $500-$4,999 for serving as a ��ɫ��al Case Development + Presentation (video) with PeerDirect (P\S\L Group). Dr. Day has received personal compensation in the range of $500-$4,999 for serving as a Content Development / Presentation (non-CME) with MJH Life Sciences (NeurologyLive). Dr. Day has a non-compensated relationship as a Clinical Director with Anti-NMDA Receptor Encephalitis Foundation that is relevant to AAN interests or activities.
Catherine Maurice, MD (Princess Margaret Cancer Centre, Toronto, Canada)	No disclosure on file
	No disclosure on file
David F. Tang-Wai, MD, FRCPC (Toronto Western Hospital/University Health Network)	Dr. Tang-Wai has nothing to disclose.

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