Preoperative electroneuromyography and myelography in cervical root compression.

The preoperative diagnostic accuracy of electroneuromyography and myelography was evaluated in 77 patients with cervical radiculopathy and/or myelopathy. In 57% of the patients, the affected root level could be determined with ENMG (accuracy 1-2 segments), 10% had a non-specific finding, and in 33% of the patients, ENMG was normal. If the symptoms had lasted less than three months, 67% of the patients had a localizing finding in ENMG. Among the 97 operated root levels, there were distinct findings in myelography in 79, minor root sheath deformities in 13, and the finding was negative in five. In addition, in myelography there were clearly pathological root sheath deformities at 20 and minor changes at 20 root levels which were not operated. ENMG and myelography have a complementary role in the diagnosis of cervical root compression. By combining the information of ENMG and myelography, the functional significance of the morphological root sheath deformities can be assessed.