Anti-NMDA receptor encephalitis outcomes in a population-based cohort

Area of Science:

• Neurology
• Immunology
• Epidemiology

Background:

• Previous anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDARE) studies may have overestimated poor outcomes and relapse rates.
• Referral center studies might underestimate mortality in anti-NMDARE.

Purpose of the Study:

• To evaluate long-term outcomes, relapse rates, and mortality in a population-based cohort of anti-NMDARE patients.
• To compare outcomes in a population-based cohort versus previous referral center studies.

Main Methods:

• Retrospective study of 72 patients with new-onset anti-NMDARE from 2009-2022.
• Data collected from Kaiser Permanente Southern California electronic health records.
• Outcomes assessed via modified Rankin Scale and mortality rates.

Main Results:

• Favorable outcomes improved from 22% at discharge to 84.5% at follow-up.
• Relapses were uncommon (4.1%), and overall mortality declined significantly after 2013.
• Early rituximab initiation increased, correlating with improved outcomes and reduced mortality.

Conclusions:

• Population-based anti-NMDARE cohorts demonstrate better long-term functional outcomes and lower relapse rates than previously reported.
• Mortality significantly decreased post-2014, linked to increased use of rituximab for treatment escalation.
• Findings suggest a more optimistic prognosis for anti-NMDARE patients in population-based settings.