遗传性压力易感性周围神经病临床神经电生理检测的意义

The value of neuroelectrophysiologic diagnosis in hereditary neuropathy with liability to pressure palsies

目的探讨遗传性压力易感性周围神经病(hereditary neuropathy with liability to pressurepalsies,HNPP)的临床神经电生理改变。方法对1个 HNPP 家系的先证者及5例家系患者进行神经传导速度检测,并对先证者进行病理组织学检查。结果先证者正中神经、尺神经、腓肠神经感觉神经传导速度(SCV)均减慢;正中神经、尺神经、腓总神经运动神经传导速度(MCV)均减慢。病理结果提示腊肠样结构改变(部分有髓神经纤维的髓鞘出现显著增厚,符合髓鞘肥厚性周围神经病的病理改变,提示 HNPP)。共检查家系中5例患者的36条神经。感觉神经传导检测结果:30条神经 SCV 异常。其中正中神经异常率12/12;尺神经异常率10/12;腓肠神经异常率8/12。感觉纤维最易累及的神经为正中神经,其次为尺神经、腓肠神经。正中神经 SCV 平均减慢35.1%,平均37.7 m/s;尺神经SCV 平均减慢31.6%,平均39.7 m/s;腓肠神经 SCV 平均减慢19.4%,平均38.6 m/s。受损程度以正中神经最重,其次为尺神经、腓肠神经。运动神经传导检测结果:运动神经诱发电位潜伏期延长者21条,所查神经远端 MCV 异常率24/36,其中尺神经异常8条,正中神经异常7条,腓总神经异常9条。减慢的尺神经沟下至腕部 MCV 平均39.7 m/s,减慢31.6%;减慢的正中神经平均50.0 m/s,减慢11.3%;减慢的腓总神经平均39.3 m/s,减慢21.2%;尺神经沟上至沟下异常率75.0%,平均40 m/s,平均减慢34.4%;腓骨小头上下异常率33.3%。减慢的 MCV 平均35.3 m/s,平均减慢31%。运动纤维最易累及的神经为腓总神经,其次为尺神经、正中神经。结论 HNPP 患者可伴有大部分神经传导障碍,可靠的神经电生理检查是诊断 HNPP 的重要依据,在无症状的 HNPP 患者及其家属也可出现神经传导障碍。在 HNPP 患者,嵌压处神经更易受损。

Objective To study the electrophysiological findings in both the clinically affected and unaffected nerves in the extremities in patients with hereditary neuropathy with liability to pressure palsies （HNPP）. Methods The sensory and motor nerve conduction velocity in the limbs of the patient with HNPP and her relatives were tested. The biopsy of sural nerve in the patient was done. Results Conducting velocities of both motor and sensory nerves （ MCV and SCV）, either medial, or ulnar or sural nerves all slowed down. Biopsy of the sural nerve of the patient showed loss of myelinated fibers, and some showed thickened myelin sheath in a sausage-like or tomacula formation, by which HNPP was considered to be characterized. The conduction velocity （NCV） of 36 nerves in the 5 relatives of the patient was tested. The SCV of 30 nerves slowed down accounting for 30/36 of all the nerves. Furthermore, all the medial nerves （ 12/12）, 10 of the 12 ulnar nerves and 8 of the 12 sural nerves respectively had an abnormal conducting velocity. The abnormal SCV of medial, ulnar and sural nerve was reduced by 35.1% , 31.6% and 19.4% , with a mean velocity of 37.7, 39. 7 and 38.6 m/s, respectively. As for the motor nerve, 58. 3% of all the nerves had delayed latency of evoked potential, 66. 7% of the distal nerve had abnormal MCV; to be specific, 66. 7% of ulnar nerves, 58. 3% of the medial nerves and 75.0% of the peroneal nerves had an abnormal rate, reducing by 31.6%, 11.3% and 21.2% , into a mean velocity of 39. 7, 50. 0, 39. 3 m/s, respectively. The decreased MCV occurred along the groove ulnar nerve in a rate of 75.0%, being 40 m/s averagely ; so it did at head of fibula in a rate of 33.3%, being 35.3 m/s averagely. Conclusions Most of the nerves exhibited a slowed conduction velocity in HNPP. A careful electrophysiologic examination can be used to make a reliable diagnosis even in asymptomatic patients with HNPP. The nerves of the clinically healthy relatives and asymptomatic patients with HNPP were similarly affected. Focal neuropathies occur mainly at common entrapment sites.