Department of Neurology and Neurophysiology, St Thomas' Hospital, Guy's and St Thomas' NHS Foundation Trust, King's Health Partners Academic Health Science Centre, London, UK; Institute of Neurology, University College London, Queen Square, London, UK.
Dev Med Child Neurol. 2013 Oct;55(10):959-62. doi: 10.1111/dmcn.12236. Epub 2013 Aug 5.
Episodic ataxia type 1 (EA1) is caused by mutations in the KCNA1 gene encoding the fast potassium channel Kv1.1 and is characterized clinically by brief episodes of ataxia and continuous and spontaneous motor unit activity. Atypical presentations, in which the predominant manifestation is related to the peripheral nervous system, may lead to the diagnosis being missed or delayed, with the potential risk of individuals receiving inappropriate or unnecessary investigations and treatment. We present a case of a 15-year-old female with EA1 who had never had episodes of ataxia, and whose hand movements were initially thought to represent a tremor. Genetic screening for KCNA1 mutations was precipitated by the results of the nerve excitability studies (TROND protocol), which showed changes typical of reduced fast potassium channel conductance. This case highlights the utility of nerve excitability studies in identifying individuals with KCNA1 mutations.
发作性共济失调 1 型（EA1）是由编码快速钾通道 Kv1.1 的 KCNA1 基因突变引起的，临床上以短暂的共济失调发作和持续自发的运动单位活动为特征。不典型表现，其主要表现与周围神经系统有关，可能导致诊断被遗漏或延迟，使个体接受不适当或不必要的检查和治疗的风险增加。我们报告了一例 15 岁女性 EA1 患者，她从未出现过共济失调发作，手部运动最初被认为是震颤。神经兴奋性研究（TROND 方案）的结果促使对 KCNA1 基因突变进行了基因筛查，结果显示出典型的快速钾通道电导降低的变化。这个病例突出了神经兴奋性研究在识别 KCNA1 基因突变个体中的作用。
