肘管综合征的临床和电生理分析

Retrospective analysis of clinical and electrophysiological characteristics of cubital tunnel syndrome

目的：探讨肘管综合征（CUTS）患者的临床和电生理特点，并分析可能的病因。方法：回顾性分析69例CuTS患者（共73侧肢体）的临床和电生理资料。神经传导检测时，采用表面电极刺激和记录。分别于腕部、肘下5cm、肘上5cm刺激尺神经，记录小指展肌复合肌肉动作电位（CMAP）。腕部刺激尺神经，于小指逆向记录感觉神经动作电位（SNAP）。测量不同节段尺神经的运动传导速度（MCV）和感觉传导速度（SCV）。针电极肌电图观察尺神经所支配肌肉静息状态下的异常自发电活动。结果：①前臂尺侧、小指及无名指尺侧半麻木48例（70％），上肢麻木及力弱19例（28％），肘部疼痛或活动受限5例（7％）；第一骨间背侧肌萎缩28例（41％），小鱼际肌萎缩15例（22％），爪形手6例（9％）；②CuTS原因不明者53例（77％）；长期、频繁操作电脑所致者8例（12％）；③尺神经肘上-肘下节段MCV减慢[（29．91±5．09）m／s]，肘下一腕段正常[（50．88±4．63）m／s]。小指展肌CMAP波幅降低，4只上肢未引出CMAP波形；尺神经腕一小指节段SCV正常[（47．43±7．27）m／s]，SNAP波幅降低，36只上肢未引出SNAP波形；肌电图显示异常自发活动者，小指展肌和第一骨间背侧肌73肢，尺侧腕屈肌29肢。结论：CuTS临床表现以前臂尺侧、小指及无名指尺侧半麻木为主，伴力弱、疼痛及尺神经支配肌肉萎缩；电生理表现以尺神经肘上、下段MCV减慢为主，伴感觉纤维受损；病因以特发性占多数，长期、频繁操作电脑为另一重要因素；神经电生理检测为诊断CuTS的可靠手段，能明确神经受损受压的部位和程度。

Objective： To investigate the clinical and electrophysiological features in patients with cubital tunnel syndrome （CUTS） and analyse the possible causes. Methods： The clinical and electrophysiologieal data in 69 patients with CuTS involving 73 upper limbs were analyzed. While nerve conduction studies were performed, and surface electrodes were used for both stimulating and recording. While ulnar nerves were stimulated at wrist and 5 cm below elbow and 5 cm above elbow, respectively, and the compound muscle action potentials （CMAP） of abductor digiti minimi were recorded. While ulnar nerves were stimulated at wrist, the sensory nerve action potentials （SNAP） were antidromically recorded from the little finger. The motor conduction velocity （MCV） and sensory conduction velocity （SCV） of ulnar nerve at different segments were measured. The abnormally spontaneous activities of muscles were innervated by ulnar nerves were observed through needle electromyographic detecting at rest. Results： Forty eight patients（70%） were presented with numbness in ulnar side of forearm, little finger and the ulnar half of the ring finger, 19 （28G）with numbness and weakness in upper limbs, 5 （7%）with pains or re stricted movement in the elbow; 28（41%） with atrophy in the first dorsal interossei, 15 （22%）with atrophy in the hypothenar muscles, 6 （9 % ） with claw-hand ; 53 patients （77 %） patients with unknown causes （12G） who frequently operated computer. The average MCV of the ulnar nerves was slowed （29.91±5.09 m/s） between the segment of above and below elbow, and normal （50.88±4.63 m/s） from below elbow to wrist respectively; the SCV of the ulnar nerves was normal （48.43±11.27 m/s） from wrist to little finger; the amplitude of CMAP and SNAP decreased; and there was no response of CMAP and SNAP elicited in 4 and 36 out of 73 involved limbs. The abnormal spontaneous activities were observed in the muscles of the first dorsal interossei and abductor digiti minimi at 73 involved limbs, and flexor carpi ulnaris at 29 limbs. Conclusion： The patients with CuTS mainly show numbness in the ulnar side of the forearm, little finger and the ulnar half of the ring finger, complicated with weakness, tingling and muscle atrophy. Idiopathic CuTS is the most common, and another important reason for CuTS is frequent and long-term operation of computer. Electrophysiological detection could provide reliable evidence for the diagnosis, and identify lesion site and severity of the involved ulnar nerves.