Characterization of the Common Symptomology and Great Mimickers of Autoimmune Encephalitis (P4-5.011)

Abstract

<h3>Objective:</h3> To identify clinical and systemic variables associated with mimickers of Autoimmune Encephalitis (AE). <h3>Background:</h3> The classical presentation of AE includes acute or subacute onset of impaired memory and cognition, in combination with progressive neurologic symptoms which may include abnormal movements, seizures, psychosis, and balance, speech, or vision problems. However, diagnosis can be challenging due to broad differential diagnoses and variable presentations of patients with suspected AE. Greater awareness of AE has led to increased consideration of AE as a potential etiology of neurologic symptoms, and accordingly, misattribution of symptoms to AE in some instances. <h3>Design/Methods:</h3> We performed a single-center retrospective chart review of 212 patients from the University of Utah Health identified by query of the ICD-10 code G04.81: Other encephalitis and encephalomyelitis between January 2012–August 2022, which is the diagnostic code inclusive of AE and other related or nonspecific encephalitis. <h3>Results:</h3> We describe the patient demographics of this cohort, as well as relevant clinical data including the predominant presenting symptom(s), cerebrospinal fluid characteristics, electroencephalography and neuroaxis imaging findings, suspected initial diagnosis, timing and duration of treatment interventions (including immunomodulatory therapy), final diagnosis, and outcomes. <h3>Conclusions:</h3> The diagnosis of AE remains challenging, especially in patient presentations with a predominant psychiatric phenotype at onset, or in those with atypical features. Recognition of the most common pitfalls to diagnosis and disease mimics may improve timely and accurate recognition of causative etiologies and help to direct the most appropriate treatments and interventions. <b>Disclosure:</b> Miss Soneji has nothing to disclose. Miss Shapiro has nothing to disclose. Dr. Wright has nothing to disclose. Dr. Noroozi Gilandehi has nothing to disclose. Miss Francis has nothing to disclose. Dr. Smith has nothing to disclose. Mr. Wong has nothing to disclose. Dr. Clardy has received personal compensation for serving as an employee of Veterans Health Administration (VHA). Dr. Clardy has received personal compensation for serving as an employee of University of Utah Health. Dr. Clardy 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 Neurology/AAN Publications. The institution of Dr. Clardy has received research support from Sumaira Foundation for NMO. The institution of Dr. Clardy has received research support from Western Institute for Veteran Research. The institution of Dr. Clardy has received research support from NIH/NINDS. Dr. Clardy has received personal compensation in the range of $500-$4,999 for serving as a AAN Summer Meeting CoDirector Travel and Lodging with AAN. Dr. Clardy has received personal compensation in the range of $500-$4,999 for serving as a Grand Rounds Travel and Lodging with U of Iowa. Dr. Clardy has received personal compensation in the range of $500-$4,999 for serving as a Speaker Honoraria for Grand Rounds with Barrow Neurological Institute. Dr. Clardy has received personal compensation in the range of $500-$4,999 for serving as a Speaker Honoraria for Grand Rounds with Beaumont Health.