H反射在脑卒中后上肢偏瘫患者中的特征表现及分析

目的:通过研究脑卒中后上肢偏瘫患者H反射的特征表现,及其与偏瘫肢体肌张力的关系,探讨H反射在脑卒中后上肢偏瘫患者神经电生理评定中的应用价值。方法:选择符合本研究入选标准的脑卒中恢复期偏瘫患者42例。分别对患者双侧正中神经、尺神经、桡神经所支配的拇短展肌、小指展肌、指总伸肌进行H反射检查,并对患侧上肢给予改良Ashworth痉挛量表(MAS)评定,确定上述神经中哪些更容易引出H反射,并对其所引出的H反射结果及其与MAS的相关性进行比较和分析。结果:患者双侧正中神经、尺神经所支配的拇短展肌、小指展肌均较易引出H反射,引出率100%。桡神经所支配的指总伸肌不易(3例/42例,引出率7.14%)引出H反射。患侧正中神经和尺神经的H反射潜伏期分别为(25.89±3.66)ms、(25.71±3.26)ms;健侧正中神经和尺神经的H反射潜伏期分别为(26.60±3.11)ms、(26.44±2.87)ms。配对t检验分析,差异均有显著性意义(P<0.05);Hmax/Mmax比值均数用中位数表示,患侧正中神经和尺神经的Hmax/Mmax比值分别为0.185和0.217;健侧Hmax/Mmax比值分别为0.126和0.112,用Wilcoxon符号秩检验分析,患侧与健侧差异均有显著性意义(P<0.05)。用Kruskal-WallisH检验分析显示:患侧上肢正中神经、尺神经H反射潜伏期在MAS不同级别中没有差异,而Hmax/Mmax比值在MAS不同级别中有差异。Spearman秩相关检验结果显示:患侧上肢正中神经H反射潜伏期、Hmax/Mmax比值以及尺神经H反射潜伏期与MAS不相关;而患侧上肢尺神经Hmax/Mmax比值与MAS存在秩相关关系。结论:上肢H反射与MAS存在一定关系,其中Hmax/Mmax比值是评估下运动神经元兴奋性的较好指标,可以成为临床评价痉挛的客观神经电生理指标。

The characteristic appearance and analysis of H reflex in hemiplegic upper extremity patients with post-stroke

Objective:To investigate the valuable application of H reflex in electrophysiological evaluation by study of the relationship between the characteristic appearance of H reflex and muscular tone of affected side in upper extremity of hemiplegic patients post-stroke.Method:Forty-two hemiplegic inpatients with post-stroke in convalescence stage who fulfilled the study entry criteria were in various levels of upper extremity dysfunction.The H reflex examination was given to abductor pollicis brevis(APB) dominanted by median nerve,abductor digiti minimi(ADM) dominanted by ulnar nerve,extensor digitorum communis dominanted by radial nerve of the patients’ both affected and unaffected sides.At the same time,affected upper extremity was assessed by modified Ashworth scale(MAS),to determine whether H reflex could be easily obtained from all the nerves above mentioned.Then the changes in H reflex latencies and ratios of Hmax/Mmax of both sides were compared;the correlation between MAS and H reflex latency and Hmax/Mmax ratio in affected upper extremities were analysed.Result:H reflex was easily obtained from APB dominanted by median nerve,ADM dominanted by ulnar nerve of both sides,and the elicitation rates were 100%.But elicitation rate of extensor digitorum communis dominanted by radial nerve was only 7.14%.The mean(SD) H reflex latencies for medium nerve and ulnar nerve of affected sides were(25.89±3.66)ms and(25.71±3.26)ms respectirely,and those of unaffected sides were(26.60±3.11)ms and(26.44±2.87)ms recpectively.The medians of Hmax/Mmax ratio value for the median nerve and ulnar nerve of affected sides were 0.185 and 0.217 respectively,and those of unaffected sides were 0.126 and 0.112 respectively.The H reflex latency reduced and the Hmax/Mmax ratio increased in affected side comparing with unaffected side for median nerve and ulnar nerve,and the differences of both sides were statistically significant(P<0.05).By using Spearman rank test,the Hmax/Mmax ratio for ulnar nerve in affected upper extremity had a rank correlation with MAS,while the H reflex latency did not.Conclusion:H reflex of upper extremity is related with MAS.Hmax/Mmax ratio is a better index for the assessment of the excitability of lower motor neurons of affected side in hemiplegic patients with post-stroke and can be used as a objective electrophysiological index of spasticity in clinical evaluation.