Differences in treatment of anti-NMDA receptor encephalitis: results of a worldwide survey.

The objective of the study was to identify differences in treatment strategies for anti-NMDA receptor encephalitis based on specialty of treating physicians, geographic location, and years in practice. We conducted an anonymous worldwide electronic survey through the Practice Current section of Neurology® Clinical Practice to appraise differences in decisions about first- and second-line treatment and timing for initiation of second-line treatment for anti-NMDA receptor encephalitis. 399 participants answered all questions of the survey and were included in the analysis. 261 (65%) were adult neurologists, 86 (22%) were neurologists treating children, and 52 (13%) were pediatric rheumatologists. 179 (45%) responders practiced in the US. The majority agreed on the use of steroids and/or IVIg for first-line therapy and rituximab alone as second line. Differences in initial treatment regimen based on specialty included increased use of plasma exchange by adult neurologists (27%) and rituximab by pediatric rheumatologists (29%) (χ 2(4) = 27.43, p < 0.001). Trainees opted for plasma exchange (35%) and junior faculty picked rituximab (15%) more as part of first line (χ 2(4) = 13.37, p = 0.010). There was greater usage of anti-metabolites for second-line therapy outside of the US (15%) (χ 2(4) = 11.67, p = 0.020). US physicians also utilized second-line treatment earlier than their mostly European counterparts (14 vs. 23% used later than 2 weeks; χ 2(1) = 4.96, p = 0.026). Although treatment patterns were similar, differences observed across specialties and geographic locations may guide the development of consensus-driven guidelines by multi-disciplinary task forces. These guidelines may promote treatment trials of immunomodulators in autoimmune encephalitides.