腓骨肌萎缩症1A型患者和慢性炎性脱髓鞘性多发性神经病患者F波改变的比较

目的：分析比较腓骨肌萎缩症1A型(Charcot-Marie-Tooth1A,CMT1A)患者和慢性炎性脱髓鞘性多发性神经病(chronic inflammatory demyelinating polyneuropathy, CIDP)患者F波改变的特点和原因。方法：收集自2012年1月到2018年12月在北京大学第三医院诊治的CMT1A和CIDP患者各30例，记录临床资料、电生理指标(神经传导速度和F波、H反射)、神经功能等级评分等，部分患者行臂丛和腰丛的磁共振影像检查，分析比较结果。结果：CMT1A患者的正中神经平均运动传导速度为(21.10±10.60) m/s, CIDP患者为(31.52±12.46)m/s,二者差异有统计学意义(t=-6.75,P<0.001), CMT1A患者中约43.3%(13/30)未引出尺神经F波，明显高于CIDP未引出F波的患者比例(4/30,13.3%),χ²=6.65,P=0.010。在可引出F波的患者中，CMT1A组患者的F波潜伏期为(52.40±17.56) ms, CIDP组为(42.20±12.73) ms...

Diagnostic value of F wave changes in patients with Charcot-Marie-Tooth1A and chronic inflammatory demyelinating polyneuropathy

Objective: To analyze and compare the characteristics and causes of F wave changes in patients with Charcot-Marie-Tooth1A (CMT1A) and chronic inflammatory demyelinating polyneuropathy (CIDP). Methods: Thirty patients with CMT1A and 30 patients with CIDP were enrolled in Peking University Third Hospital from January 2012 to December 2018. Their clinical data, electrophysiological data(nerve conduction velocity, F wave and H reflex) and neurological function scores were recorded. Some patients underwent magnetic resonance imaging of brachial plexus and lumbar plexus, and the results were analyzed and compared. Results: The average motor conduction velocity (MCV) of median nerve was (21.10±10.60) m/s in CMT1A and (31.52±12.46) m/s in CIDP. There was a significant difference between the two groups (t=-6.75, P < 0.001). About 43.3% (13/30) of the patients with CMT1A did not elicit F wave in ulnar nerve, which was significantly higher than that of the patients with CIDP (4/30, 13.3%), χ²=6.65, P=0.010. Among the patients who could elicit F wave, the latency of F wave in CMT1A group was (52.40±17.56) ms and that in CIDP group was (42.20±12.73) ms. There was a significant difference between the two groups (t=2.96, P=0.006). The occurrence rate of F wave in CMT1A group was 34.6%±39%, and that in CIDP group was 70.7%±15.2%. There was a significant difference between the two groups (t=-5.13, P < 0.001). The MCV of median nerve in a patient with anti neurofascin 155 (NF155) was 23.22 m/s, the latency of F wave was 62.9-70.7 ms, and the occurrence rate was 85%-95%. The proportion of brachial plexus and lumbar plexus thickening in CMT1A was 83.3% (5/6) and 85.7% (6/7), respectively. The proportion of brachial plexus and lumbar plexus thickening in the CIDP patients was only 25.0% (1/4, 2/8). The nerve roots of brachial plexus and lumbar plexus were significantly thickened in a patient with anti NF155 antibody. Conclusion: The prolonged latency of F wave in patients with CMT1A reflects the homogenous changes in both proximal and distal peripheral nerves, which can be used as a method to differentiate the CIDP patients characterized by focal demyelinating pathology. Moreover, attention should be paid to differentiate it from the peripheral neuropathy caused by anti NF155 CIDP. Although F wave is often used as an indicator of proximal nerve injury, motor neuron excitability, anterior horn cells, and motor nerve myelin sheath lesions can affect its latency and occurrence rate. F wave abnormalities need to be comprehensively analyzed in combination with the etiology, other electrophysiological results, and MRI imaging.