Utility of flexor carpi radialis h-reflex in diagnosis of cervical radiculopathy.

PURPOSE: The sixth and seventh roots are among the most common roots involved in cervical radiculopathy. The aim of this study was to evaluate the diagnostic value of flexor carpi radialis H-reflex in patients with suspected C6 or C7 root lesion. METHODS: This study was performed on 42 controls and 38 patients with suspected C6 or C7 radiculopathy. All patients were evaluated by physical examination, electromyogram, nerve conduction study and flexor carpi radialis H-reflex (superficial technique), and cervical magnetic resonance imaging. Side-to-side difference >1 millisecond or ipsilateral absent H-responses is considered as an abnormal response. Results were analyzed with SPSS. RESULTS: Specificity and sensitivity of H-reflex are 86% and 50% in C6 radiculopathy and 86% and 75% in C7, respectively. In six (54.5%) patients without electromyogram finding, flexor carpi radialis H-response was ipsilaterally abnormal. The mean of H-latency in control group was 15.7 (+/-1) milliseconds, and mean of side-to-side H-latency difference in this group was 0.43 (+/-0.39) milliseconds. CONCLUSION: Flexor carpi radialis H-reflex can be a helpful additional technique to routine needle electromyogram in the diagnosis of root lesions. The probability of abnormal flexor carpi radialis H-reflex in C7 root lesion is higher than that of C6 root lesion; however, it was not statistically significant.