2026 American Academy of Neurology Autoimmune Abstract Website

Ka-Ho Wong¹, Gregory Day², James Torner³, Christopher Coffey³, David Clifford⁴, Ursula Utz⁵, Eric Klawiter⁶, J. Singleton⁷, Dixie Ecklund³, David Klements⁶, Michele Costigan⁸, Erin Steinhart⁶, Brenda Pearson³, Christina Desir⁶, Josep Dalmau⁹, Maarten Titulaer¹⁰, Stacey Clardy¹¹
¹U of U Neurology Clinic, ²Mayo Clinic, ³University of Iowa, ⁴Washington University School of Med, ⁵NIH, ⁶Massachusetts General Hospital, ⁷University of Utah Department of Neurology, ⁸University of Iowa College of Public Health, ⁹ICREA-IDIBAPS-Hospital Clinic, ¹⁰Erasmus Medical Center, ¹¹University of Utah

Objective:

To develop and implement an adapted modified Rankin Scale (mRS) that captures cognitive, behavioral, and psychiatric contributors to functional disability in patients with NMDARE.

Background:

The mRS is a 7-point global disability scale originally developed for stroke, with a primary emphasis on motor function. However, NMDARE is characterized by prominent psychiatric, cognitive, and behavioral impairment that is not adequately captured by the standard mRS. At the initiation of the ExTINGUISH trial, no prospectively validated functional outcome measure existed to comprehensively assess the multidimensional disability associated with anti–N-methyl-D-aspartate receptor encephalitis (NMDARE).

Design/Methods:

The ExTINGUISH mRS was collaboratively developed by protocol co-investigators and the NeuroNEXT Coordinating Centers to expand the standard mRS framework by incorporating structured assessment of cognitive, behavioral, and psychiatric domains. To ensure reliability and consistency across sites, investigators completed standardized training and certification prior to use. Scoring consistency was further supported through algorithmic guidance, centralized adjudication, and ongoing rater calibration. The ExTINGUISH mRS serves as the primary outcome of the ExTINGUISH trial and is analyzed as a ranked composite endpoint incorporating change in functional status from randomization to 16 weeks, use of rescue therapy, and time to recovery.

Results:

Implementation of the ExTINGUISH mRS enabled standardized, multidimensional functional outcome assessment across trial sites. Integration of structured training, centralized adjudication, and real-time quality monitoring ensured high scoring consistency and minimized inter-rater variability. The adapted scale effectively operationalized both motor and non-motor contributors to disease-related disability.

Conclusions:

The ExTINGUISH mRS provides a rigorously standardized, multidimensional functional outcome measure that improves assessment of treatment response in NMDARE. By capturing psychiatric, cognitive, and motor domains of disability, it enhances the sensitivity and reliability of outcome measurement and establishes a new benchmark for functional assessment in autoimmune encephalitis clinical trials.