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.