Autoimmune Encephalitides and Beyond: Atypical Presentations, The Expanding Role of Autoimmunity, and Practical Implications for Management

Abstract: While CL psychiatrists are familiar with the classic red-flags of autoimmune encephalitides
(AEs) that necessitate neurologic work-up, we also encounter atypical neuropsychiatric
presentations that fall into an ambiguous territory between specialties. In these patients, the role
of autoimmunity and the next step in management can be unclear. Often, the neurologic
manifestations may be deemed insufficient to justify further workup or treatment, yet the
behavioral presentation too unusual to be considered exclusively psychiatric.

Furthermore, because AEs have severe consequences and require prompt treatment, clinical
suspicion must remain high. However, definitive diagnostic confirmation requires a time-
consuming laboratory send-out which only confirms established antibodies, excluding those that
remain unidentified but relevant to pathogenesis. Consequently, treatment is virtually always
empirical. For the CL psychiatrist, this underscores the value of performing a targeted
neurologic exam and interpreting equivocal laboratory values in the absence of an identifiable
autoantibody.

Given these issues, we often find ourselves in a clinical predicament. On one hand, delaying a
potentially curative treatment increases the risk of persistent neuropsychiatric sequelae and the
exposure to unnecessary antipsychotic load. On the other hand, pursuing the “million-dollar”
neurologic workup or giving immunomodulatory treatment for an indeterminate entity also risks
iatrogenic harm and promotes unrealistic expectations for families who frequently find such
diagnoses more palatable than traditional psychiatric diagnoses.

In this interactive workshop, an interdisciplinary team of experts will provide a nuanced and
practical update of these issues to optimize clinical decision making. Before we begin each
topic, we lead with a case presentation, inviting participants to collaborate in developing a
differential diagnosis and management plan.

Dr. Hu will describe the importance of this topic, the expanding role for CL psychiatrists, then introduce the speakers.
(10 minutes)

Dr. Kruse, CL fellowship director at UCLA, who has conducted NIH-funded research at the
intersection of inflammation and mood, will review established management of the autoimmune
encephalitides, including when to suspect autoimmunity in the setting of a predominantly
psychiatric presentation and how to liaison and advocate for further work-up in challenging
clinical situations. (20 minutes)

Dr. McKeon, autoimmune neurologist and co-director of the Neuroimmunology Laboratory at the
Mayo Clinic, will review the neurological work-up when an autoimmune neuropsychiatric
presentation is suspected, highlight the relevant aspects of the neurologic examination in such
patients, and describe the decision process to trial immunotherapy in the absence of an
identifiable neural autoantibody. (20 minutes)

Dr. Bartley, a clinical immunopsychiatrist and Howard Hughes research fellow, will introduce the
field of autoimmune psychiatry with an emphasis on the emerging diagnostic construct of
autoimmune psychosis. He will then describe his ongoing research on the identification of novel
biomarkers in the future. (25 minutes)

The floor will open for audience members to discuss. (15 minutes)