Symptomatic treatment of children with anti‐NMDAR encephalitis

Aim We performed the first study on the perceived benefit and adverse effects of symptomatic management in children with anti‐ N ‐methyl‐ d ‐aspartate receptor ( NMDAR ) encephalitis. Method A retrospective chart review was undertaken at two tertiary paediatric hospitals in Australia and New Zealand. We included 27 children (12 males, 15 females; mean age at admission 7y 1mo) with anti‐ NMDAR antibodies in serum or cerebrospinal fluid with a typical clinical syndrome. Results Only two out of 27 patients were white, whereas 16 out of 27 patients were from the Pacific Islands/New Zealand Maori. The mean duration of admission was 69 days (10–224d) and 48% of patients (13/27) needed treatment in an intensive care setting. A mean of eight medications per patient was used for symptomatic management. Symptoms treated were agitation ( n =25), seizures ( n =24), movement disorders ( n =23), sleep disruption ( n =17), psychiatric symptoms ( n =10), and dysautonomia ( n =four). The medications used included five different benzodiazepines ( n =25), seven anticonvulsants ( n =25), eight sedatives and sleep medications ( n =23), five antipsychotics ( n =12), and five medications for movement disorders ( n =10). Sedative and sleep medications other than benzodiazepines were the most effective, with a mean benefit of 67.4% per medication and a mean adverse effect‐benefit ratio of 0.04 per medication. Antipsychotic drugs were used for a short duration (median 9d), and had the poorest mean benefit per medication of 35.4% and an adverse effect‐benefit ratio of 2.0 per medication. Interpretation Long‐acting benzodiazepines, anticonvulsants, and clonidine can treat multiple symptoms. Patients with anti‐ NMDAR encephalitis appear vulnerable to antipsychotic‐related adverse effects. Pacific Islanders appear to have a vulnerability to anti‐ NMDAR encephalitis in our region.