[Value of neurophysiologic methods in the follow-up of Cloward's multiple cervical vertebral fusion]

In 11 patients suffering from radicular and in some cases also medullary symptoms anterior spinal fusion at 2 or 3 cervical levels was performed. At follow-up radicular pain had disappeared, and no clinical deficits were found with the exception of one previously tetraparetic patient. Neurophysiological studies including needle electromyography, conduction velocity studies and somatosensory evoked potentials showed, however, that denervation potentials persisted frequently in the C7-C8-T1 innervated muscles, while those innervated by the upper cervical roots were normal in all patients. Somatosensory evoked potentials could not detect medullary compression due to "angulation deformity", a frequent complication of multiple spinal body fusion.