【摘要】 目的 脊髓性肌萎缩症(SMA)的临床表型诊断基于发病年龄和运动功能，但可能受到一些其他因素的影响。本研究旨在分析SMA 2型和3型患者的神经电生理特征，以协助其表型诊断。方法 对25例2型SMA患者和26例3型SMA患者进行回顾性研究。收集患者的临床数据和电生理结果并进行比较。对复合肌肉动作电位(CMAP)波幅进行受试者工作特征(ROC)曲线下面积(AUC)检验，明确其对SMA表型诊断的价值及标准。结果 SMA 2型及3型患者在发病年龄、下肢肌力、肌酶及CMAP波方面存在差异，且CMAP改变存在以下特点：(1)两组患者均出现普遍性CMAP波幅下降，但2型较3型降低更为显著；(2)两组患者均以股神经CMAP波幅降低最为显著；(3)上肢远端神经以尺神经CMAP波幅降低明显，下肢胫神经CMAP波幅降低较明显；(4)对于两组患者的SMA分型诊断，每条神经中的CMAP波幅都有独特的临界值。正中神经的临界值为5.060 mV(AUC=0.948),尺神经为3.170 mV(AUC=0.889),腓总神经为3.095 mV(AUC=0.949),胫神经为2.920 mV(AUC=0.990),腋神经为4.390 mV(AUC=0.873),股神经为0.965 mV(AUC=0.855)。结论 SMA患者有较典型的临床和神经电生理特点，CMAP波幅可作为区分2型与3型患者的有效电生理指标。更多还原

【Abstract】 Objective Diagnosing clinical phenotype of spinal muscular atrophy(SMA) was based on age of onset and motor function, but may be influenced by some other factors. The aim of this study was to analyze the neuroelectrophysiological characteristics of patients with type 2 and type 3 SMA to assist in their phenotype diagnosis. Methods A retrospective study was conducted on 25 patients with type 2 SMA and 26 patients with type 3 SMA. Clinical data and electrophysiological results of the patients were collected and compared. Receiver operating characteristic(ROC)analysis was conducted on compound muscle action potential(CMAP) amplitudes. Area under ROC curve(AUC) was used to establish a cutoff value and criteria for SMA phenotype diagnosis. Results There were significant differences in age of onset, muscle strength of lower extremities, creatine kinase and CMAP wave between type 2 SMA patients and type 3 SMA patients. CMAP changes exhibited the following characteristics:(1) Both groups of the patients showed a general decrease in CMAP amplitude, but the decrease was more significant in type 2 than in type 3.(2) Both groups of the patients showed the most significant decrease in CMAP amplitude of the femoral nerve.(3) The distal nerves of the upper limbs showed a significant decrease in CMAP amplitude in the ulnar nerve, while the tibial nerve of the lower limbs had a significant decrease in CMAP amplitude.(4) For SMA classification diagnosis of two groups of the patients, there was a unique critical value for CMAP amplitude in each nerve. The critical values for the median nerve were 5.060 mV(AUC=0.948), ulnar nerve 3.170 mV(AUC=0.889), common peroneal nerve 3.095 mV(AUC=0.949), tibial nerve 2.920 mV(AUC=0.990), axillary nerve 4.390 mV(AUC=0.873) and femoral nerve 0.965 mV(AUC=0.855), respectively. Conclusion Patients with SMA have typical clinical and neuroelectrophysiological characteristics, and CMAP amplitude may be used as an effective electrophysiological indicator to distinguish type 2 patients from type 3 patients.更多还原