Observations on the application of electrophysiological methods in the diagnosis of cervical root compressions

20 patients who had clinical symptoms and/or signs of compression of the 7th and/or 6th cervical roots were examined. Motor and sensory nerve conduction velocities, velocities in the proximal segment of the median nerve determined by measuring F-wave latencies, cervical somatosensory evoked potentials, and needle electromyographic records of the Mm. deltoideus, biceps brachii, triceps brachii, abductor pollicis brevis, and abductor digiti quinti were investigated. Only in 11 out of the 20 patients electromyographical results coincided with the clinical findings with regard to the level of the root lesion. F-wave conduction velocities within the proximal segment of the median nerve were completely normal. Somatosensory evoked potentials revealed alterations in 8 cases; 2 of them showed an additional alteration on the clinically apparently healthy side. In our opinion the various electrophysiological methods seem to have only a limited value in the diagnosis and localization of cervical root compression syndromes.