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(A (R)) 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%) (chi (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 (chi (2)(4) = 13.37, p = 0.010). There was greater usage of anti-metabolites for second-line therapy outside of the US (15%) (chi (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; chi (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.