A Comparison Between Root Stimulation and Needle Electromyography in C7 Radiculopathies

Abstract

Background: Needle electromyography (EMG) is most useful electrophysiological tool in the diagnosis of radiculopathies. However, EMG findings may not be apparent especially in patients with slight axonal damage. Objective: In this study, we aimed that ta analyze the usefulnes of cervical root stimulation in the diagnosis of cervical radiculopathies. Material and Methots: Twenty-six patients with C7 radiculopathy and 20healthy controls were included to this study. Conventional needle EMG and monopolar needle cervical root stimulation were performed to the all subjects. Triceps muscle was used in recording of compound muscle action potentials (M responses) evoked by C7 root stimulation and Erb point stimulation. The latencies and peak to baseline amplitudes of M responses evoked by C7 root stimulation Erb point stimulation were analyzed. Additionally, the latency difference (short segment conduction time) and the amplitude ratios of these potentials were calculated. Findings: The amplitude of M response evoked by cervical root stimulation and root-Erb amplitude ratio were significantly decreased in patient group. Short segment conduction time obtained from symptomatic side of patients was moderately prolonged in comparison to the controls. The sensitivites of EMGand cervical root stimulation was similar (16/26 patients, 61.5%). Nineteen patients had at least one electrophysiological abnormality in this study (73.1%). Conclusion: We concluded that cervical root stimulation can be helpful in patients with cervical radiculopathies when EMG failed in the demonstration of axonal damage due to radiculopathy.