A preoperative and postoperative study of the accuracy and value of electrodiagnosis in patients with lumbosacral disc herniation.
Twenty patients with a radicular syndrome, who underwent surgery for unilevel lumbosacral disc herniations verified by computed tomography were investigated with neurophysiologic tests (electromyograms, F-responses, dermatome somatosensory evoked potentials) preoperatively and 1 year postoperatively. At least one test revealed a pathologic abnormality preoperatively in 13 patients, but in 5 patients only the nerve root level corresponded to computed tomographic findings. Discordance between neurophysiologic and radiologic findings did not predict a surgical success rate. if all neurophysiologic tests were normal the outcome was significantly worse than if any of the tests showed an abnormality (P < 0.01). Four patients who were improved after surgery still had abnormal neurophysiologic findings. In conclusion, neurophysiology is not useful to diagnose the exact level of a nerve root lesion, but may reveal whether it is present. Electrodiagnosis is recommended if radiology and clinical testing conflict. If positive, it may then serve to justify surgical exploration.
Tullberg
T
T
Department of Orthopaedics, St. Górans Hospital, Stockholm, Sweden.
Svanborg
E
E
Isaccsson
J
J
Grane
P
P
D000328:Adult; D004576:Electromyography; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000175:diagnosis* / Q000453:epidemiology / Q000601:surgery; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D011237:Predictive Value of Tests; D012447:Sacrum; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome