MAGNETIC STIMULATION AS A DIAGNOSTIC-TOOL IN CERVICAL NERVE ROOT COMPRESSION AND COMPRESSION-INDUCED NEUROPATHY

Magnetic stimulation of motor cortex and cervical spinal cord was used to assess motor impairment in patients with either cervical nerve roo t compression or myelopathy. Evoked potentials were recorded from bice ps brachii and abductor pollicis brevis. Our interest centered on whet her the paresis resulting from root compression is accompanied by an i ncreased latency of magnetically evoked muscle potentials and whether latency is increased in cases of cervical root compression or myelopat hy in which no paresis occurs. Latency increase does appear to be a mo derately good indicator of disturbed nerve conduction. In particular, prolonged latencies in cases of ''subclinical'' paresis could be used as an important diagnostic tool for the early detection of motor defic its in cervical compression radiculopathy and myelopathy.