Altered axonal excitability properties injuvenile muscular atrophy of distal upperextremity (Hirayama disease)
Altered axonal excitability properties injuvenile muscular atrophy of distal upperextremity (Hirayama disease)
复制标题
上肢远端幼年性肌萎缩症（平山病）轴突兴奋性特性改变
DOI：
10.1016/j.clinph.2010.06.015
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Kuwabara S.
中科院分区：
文献类型：
--
作者：
Sawai S;Misawa S;Kanai K;Isose S,Shibuya K;Noto Y;Fujimaki Y;SekiguchiY;Nasu S;Nomura F;Kuwabara S.
幼年型上肢远端肌萎缩（平山病）的特征是幼年发病的不对称性肌萎缩，但其病理生理机制尚未完全阐明。“冷麻痹”，暴露于寒冷时肌肉无力加重，是这种疾病的特征。本研究的目的是探讨在平山diseases. METHODS阈值跟踪轴突兴奋特性的变化被用来测量强度持续时间常数（SDTC），阈值电紧张，不应性，和超常的正中运动轴突在手腕的14例患者和10个年龄匹配的正常对照。在室温下和冷却后进行测量，结果显示，TSPs患者的SDTC延长，阈值电张力曲线呈扇形，不应期和超常性增加。冷却后，有类似的变化，在患者和正常人，兼容轴突去极化可能是由于麻痹的钠-钾pump.CONCLUSIONSmotor轴索兴奋性平山病的特点是持续性钠电流增加，短暂的钠和钾通道功能障碍可能与突出的侧支发芽在年轻人。需要进一步的研究来阐明冷麻痹的机制。意义轴突兴奋性评估可以提供神经源性肌萎缩疾病如平山病的离子机制的特征。
OBJECTIVEJuvenile muscular atrophy of distal upper extremity (Hirayama disease) is characterized by juvenile-onset of asymmetric amyotrophy, but the pathophysiology has not been fully clarified. “Cold paresis”, aggravation of muscle weakness with exposure to cold, is a characteristic feature of this disease. The aim of this study was to investigate changes in axonal excitability properties in Hirayama disease.METHODSThreshold tracking was used to measure strength-duration time constant (SDTC), threshold electrotonus, refractoriness, and supernormality in median motor axons at the wrist of 14 patients and 10 age-matched normal controls. The measurements were performed at room temperature and after cooling.RESULTSPatients showed prolonged SDTC, fanning-out of threshold electrotonus curves, and increased refractoriness and supernormality. After cooling, there were similar changes in patients and normal subjects, compatible with axonal depolarization possibly due to paralysis of sodium–potassium pump.CONCLUSIONSMotor axonal excitability in Hirayama disease were characterized by increased persistent sodium currents, and dysfunction of transient sodium and potassium channels possibly associated with prominent collateral sprouting in young individuals. Further studies will be required to elucidate mechanisms for cold paresis.SIGNIFICANCEAssessment of axonal excitability could provide characteristic features of ionic mechanisms in diseases with neurogenic amyotrophy such as Hirayama disease.