磁刺激H反射结合F波测定对骶1感觉神经根病变的诊断价值

Value of the H reflex elicited by magnetic stimulation and the F wave in the diagnosis of S1 radiculopathy

目的通过磁刺激骶1（S1）神经根引出H反射并结合F波测定评估腰骶神经根病患者的感觉神经根功能。方法检测30名健康受试者和30名单侧S1神经根受损的患者，在双侧比目鱼肌分别记录磁刺激骶1神经根引出的H反射和电刺激胭窝处胫神经引出的F波，同时记录各自的M波，计算感觉神经根传导时间（SRCT），并分析正常人SRCT与身高、年龄的关系及其与疼痛程度的相关性。结果正常组的平均SRCT为（3．10±0.44）ms，侧间差为（0．13±0．19）ms；病例组平均SRCT及侧间差分别为（3．90±0．65）ms和（0．90±0.50）ms，均较正常组显著延长（P〈0．01）。所检正常人的SRCT与身高相关，与年龄无明显相关性。病例组的SRCT与疼痛程度呈正相关，但相关系数较低。结论SRCT可作为评价感觉神经根功能的一项指标，为骶1神经根病的无创性电诊断提供了一个新的方法。

Objective To explore a new electrodiagnostic approach using the H reflex elicited by magne- tic stimulation of the S1 nerve root and F waves to evaluate sensory nerve root function in patients with S1 radiculopathy. Methods Thirty normal subjects and 30 patients with unilateral S1 radiculopathy were recruited in this study. H reflex and M response were recorded from the bilateral soleus of all the subjects by magnetic stimulation of S, nerve roots. F and M wave responses elicited by electrical stimulation of bilateral tibial nerves at the popliteal fossa were also recorded. The sensory root conduction time （SRCT） was calculated. Correlations of age and body height with SRCT in the healthy subjects, and between SRCT and pain in the patients with S1 radiculopathy were analyzed. Results The mean values of normal subjects were 3.10 ±0.44 ms for SRCT, and 0.13 ± 0.19 ms for inter-side SRCT differences. In the 30 patients with S1 radiculopathy, H reflex could not be elicited from 4 patients. Among the remaining patients, the SRCT of the affected side was prolonged significantly （3. 90 ± 0.65 ms） , and the mean value of the inter-side difference increased significantly （0.90 ± 0.50 ms）. A regression equation correlating SRCT with height was developed, but no significant correlation between SRCT and age in the normal subjects was revealed. There was positive correlation between SRCT and the severity of pain among the patients. Conclusion SRCT can be used as a new eleetrodiagnostie index in estimating sensory nerve root function in patients with S1 radieulopathy.