Utility of H-reflex in the Diagnosis Cervical Radiculopathy

Lee, Jun; Park, Gun Ju; Doo, Hyun Cheol; Park, Sung Geon; Jeong, Yun Seog; Hah, Jung Sang

Abstract

H-reflex is a kind of late respons which can be used for the proximal nerve conduction study. Also it is a useful and widely used nerve conduction technique es to look electrically at the monosynaptic reflex. Although recordable from all muscles theoretically, H-reflexes are most commonly recorded from the calf muscles following stimulation of the tibial nerve in the popliteal fossa. But in this study, We tried to establish the normal data and to evaluate the significance of the H-reflex study in cervical radiculopathy. H-reflexes were recorded from flexor carpi radialis (FCR) muscle, extensor carpi radialis (ECR) muscle, brachioradialis (BR) muscle, and abductor digiti minimi (ADM) muscle in 31 normal adults (62 cases) and 12 patients with cervical radiculopathy. The mean values of H-reflex latency in normal control group were 16.16+/- 1.65 msec in FCR; 15.99+/- 1.25 msec in ECR; 16.47+/- 1.59 msec in BR; 24.46+/- 1.42 msec in ADM. And the mean values of side to side difference of H-reflex latency were 0.47+/- 0.48 msec in FCR; 0.68+/- 0.72 msec in ECR; 0.63+/- 0.43 msec in BR; 22.31+/- 1.24 msec in ADM. Mean values of side to side differences of interlatency time were 0.49+/-0.47 msec in FCR; 0.73+/- 0.62 msec in ECR; 0.79+/- 0.71 msec in BR; 0.69+/- 0.44 msec in ADM. Also, there were no significant differences in H-reflex latency between right and left side. H-reflex tests in patient group with cervical radiculopathy revealed abnormal findings in 11 out of 12 patients. These results suggest that H-reflex in the upper extremity would be helpful in the diagnosis of the cervical radiculopathy.