2026 American Academy of Neurology Abstract Website

Justin Levinsky¹, Lana Sladoje¹, Mary Jane Lim-Fat², Alexandra Muccilli³, Gregory Day⁴, Sarah Lapointe⁵, Seth Climans⁶, Richard Wennberg¹, David Tang-Wai⁷, Julien Hebert⁸
¹Medicine, Division of Neurology, Toronto Western Hospital, ²Medicine, Division of Neurology, Sunnybrook Health Sciences Centre, ³Saint Michael's Hospital - Multiple Sclerosis Clinic, ⁴Mayo Clinic, ⁵CHUM, ⁶London Health Sciences Centre, ⁷Toronto Western Hospital/University Health Network, ⁸Toronto Western Hospital (University Health Network)

Objective:

We examined temporal trends and identified factors associated with time to immunotherapy in patients with AE.

Background:

Early treatment of patients with autoimmune encephalitis (AE) is associated with improved long-term outcomes.

Design/Methods:

Patients diagnosed with probable or definite AE with symptomatic disease onset between January 1^st, 2007, and December 31^st, 2024, were identified at a single center (University Health Network [UHN], Toronto, ON, Canada). The primary outcome was the number of days from symptomatic onset to immunotherapy initiation. The association between time to treatment and year of symptomatic onset, antibody test results, reported ethnicity, requirement for intensive care unit (ICU) admission, and associated neoplasm was analyzed using multivariable linear regression adjusted for age and sex.

Results:

Among 91 patients with AE (59 females, 65%), 65 (71%) had positive antibody testing, and the median time to immunotherapy treatment was 45 days (range: 0−3316). Time to treatment decreased by 9.5% per year (CI_95%: 2% to 16.5% decrease; p = 0.018), and was 66% lower in patients admitted to the ICU (CI_95%: 31% to 84% decrease; p = 0.004). Delays were 232% longer in patients with GAD65 positive antibodies (CI_95%: 9% to 918% increase; p = 0.035) compared to NMDAR positive antibodies (35% decrease; CI_95%: 73% decrease to 55% increase; p = 0.3).

Conclusions:

Since its inception as a distinct disease entity in 2007, time to immunotherapy in AE has significantly decreased. Patients with GAD65 antibodies experienced significantly longer delays to treatment, compared to NMDAR antibodies. The observed decrease in time to immunotherapy may reflect increased clinical recognition of AE, improved access to antibody testing, and the establishment of a dedicated AE clinic at UHN.