Management of Refractory Orofacial Dyskinesia Caused by Anti-N-methyl-d-aspartate Receptor Encephalitis Using Botulinum Toxin

Abstract

The use of botulinum neurotoxin serotype A (BoNT-A) injections for the treatment of orofacial dyskinesia secondary to anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is rarely reported. Here, we report a case of an urgent, successful management of severe orofacial dyskinesia in an 8-year-old girl with anti-NMDAR encephalitis using BoNT-A injection. The patient presented with de novo unilateral paroxysmal movement disorder progressing to generalized dystonia and repetitive orofacial dyskinesia. Diagnosis was confirmed by the presence of NMDAR antibodies in serum and cerebrospinal fluid. The orofacial dyskinesia worsened despite the aggressive use of first-line immunotherapy and second-line immunotherapy (rituximab), and resulted in a potentially fatal self-inflicted oral injury. We urgently attempted symptomatic management using BoNT-A injections in the masseter, and induced muscle paralysis using vecuronium. The patient’s severe orofacial dyskinesia was controlled. We observed the effects of the BoNT-A injections and a tapering off of the effects of vecuronium 10 days after the treatment. The movement disorder had improved significantly 4 weeks after the first administration of rituximab. The injection of BoNT-A into the masseter may be an effective treatment for medically refractory orofacial dyskinesia in pediatric patients with anti-NMDAR encephalitis. We propose that the use of BoNT-A injections should be considered early to avoid self-inflicted oral injury due to severe refractory orofacial dyskinesia in patients with anti-NMDAR encephalitis.

Association between clinical factors and orofacial dyskinesias in anti‐N‐methyl‐D‐aspartate receptor encephalitis

“…Previous studies have reported OFLD as a possible indicator of illness progression, which may assist in clinical assessment and treatment planning (Duan et al., 2016 ; Epstein & Difazio, 2007 ; Morales‐Briceño & Fung, 2017 ; Zheng et al., 2018 ). Moreover, current literature suggests that co‐morbid MDs are more common in biologically female individuals diagnosed with anti‐NMDAR encephalitis (Varley et al., 2019 ).…”

Orofacial Dyskinesia and Intractable Hiccups in a Patient with Varicella-zoster Virus Encephalomyelitis

“…While orofacial dyskinesia, as a type of involuntary movement, is commonly seen as an extrapyramidal side effect of antipsychotics ( 18 ), patients with Huntington's disease, chronic hepatic encephalopathy, or infectious or paraneoplastic encephalitis can also show these abnormal movements ( 19 ). Oral involuntary movements are also observed in some forms of limbic encephalitis, although no definitive conclusions have been reached regarding the underlying mechanisms ( 20 , 21 ). The present case had no clinical history involving drug use or diseases that could cause dyskinesia.…”

Cervical Dystonic Tremor and Dysphonia—Rare Presentation of Anti–N‐Methyl‐D‐Aspartate Encephalitis and Its Management

“…Re‐emergence of the dystonic tremor within 5 months despite a partial resolution in MRI and no new lesion indicated that the earlier improvement occurred as a result of the botulinum toxin. Prior to this, botulinum toxin has been documented to be used once for anti‐NMDARE MDs 8 . In this case, botulinum toxin was administered early on in the treatment regime to optimize the young patient's functionality and quality of life 9 .…”