Supplementary Material for: Efficacy of Deep Brain Stimulation in a Patient with Genetically Confirmed Chorea-Acanthocytosis

Chorea-acanthocytosis (ChAc) is a rare autosomal recessive neurodegenerative disease due to mutation of the VPS13A gene encoding the protein chorein. ChAc is a slowly progressive disorder that typically presents in early adulthood, and whose clinical features include chorea and dystonia with involuntary lip, cheek, and tongue biting. Some patients also have seizures. Treatment for ChAc is symptomatic. A small number of ChAc patients have been treated with bilateral deep brain stimulation (DBS) of the globus pallidus interna (GPi), and we now present an additional case. Patient chart, functional measures, and laboratory findings were reviewed from the time of ChAc diagnosis until 6 months after DBS surgery. Here, we present a case of ChAc in a 31-year-old male positive for VPS13A gene mutations who presented with chorea, tongue biting, dysarthria, weight loss, and mild cognitive dysfunction. DBS using monopolar stimulation with placement slightly lateral to the GPi was associated with significant improvement in chorea and dysarthria. This case adds to the current state of knowledge regarding the efficacy and safety of bilateral GPi-DBS for symptomatic control of drug-resistant hyperkinetic movements seen in ChAc. Controlled trials are needed to better assess the impact and ideal target of DBS in ChAc.

舞蹈纹状细胞病（ChAc）是一种由编码舞蹈蛋白的VPS13A基因突变引起的罕见常染色体隐性神经退行性疾病。ChAc病程缓慢进展，通常于成年早期发病，其临床表现包括舞蹈病、肌张力障碍以及不自主的唇、颊、舌咬伤。部分患者伴有癫痫发作。ChAc的治疗以对症治疗为主。少数ChAc患者接受了双侧苍白球内侧核（GPi）深部脑刺激（DBS）治疗，本研究现进一步报道一例病例。从ChAc诊断时间至DBS手术6个月后，回顾了患者的病历、功能测量和实验室检查结果。本研究报道了一例31岁男性患者，其VPS13A基因突变阳性，表现为舞蹈病、舌咬伤、构音障碍、体重减轻及轻度认知功能障碍。采用单极刺激，并将刺激电极放置在GPi略外侧的位置进行DBS治疗，与舞蹈病和构音障碍的显著改善相关。本案例丰富了关于双侧GPi-DBS对舞蹈纹状细胞病中药物难治性运动障碍症状控制的有效性和安全性的现有知识。需要开展对照试验以更好地评估DBS在ChAc中的影响和理想靶点。