EMG before and after cervical anterior discectomy.

Introduction - In patients with cervical root syndromes, the relation between clinical findings and EMG results, the value of the registration of the H-reflex latency of the flexor carpi radial muscle (HFCR) and the rate of recovery of EMG abnormalities following surgery are unclear. Methods - In 68 patients with cervical radicular syndromes caused by intervertebral disc lesions, EMG was made shortly before anterior cervical discectomy and four months later. EMG consisted of needle myography and bilateral determination of the HFCR. Results - Results of HFCR were unrelated to findings on needle myography. Preoperative EMG abnormalities were related to more severe clinical and myelographic findings. A preoperative abnormal HFCR correlated with good clinical outcome. No relation was found between the clinical outcome and EMG-findings during follow-up. Conclusion - Determination of HFRC is a useful EMG-test, but further comparison to tendon reflexes is necessary. EMG identifies patients with more severe root lesions, but cannot be used for evaluation of persistent complaints within the first half year following surgery.