Diagnosis of the level of the cervical myelomathy by using the motor evoked potentials following transcranial magnetic stimulation

• Published in: Orthopedics & Traumatology Vol. 46; no. 3; pp. 929 - 933
• Main Authors: Morita, Hideki, Fuchigami, Yasunori, Kaneko, Kazuo, Taguchi, Toshihiko, Itou, Yutaka, Sugiyama, Toshihiro, Kawai, Shinya
• Format: Journal Article
• Language: English
• Published: West-Japanese Society of Orthopedics & Traumatology 1997
• Subjects: Cervical Myelopathy; Evoked Spinal Cord Potentials; Magnetic Stimulation; Motor Evoked Potentials
• ISSN: 0037-1033; 1349-4333
• DOI: 10.5035/nishiseisai.46.929

Motor evoked potentials (MEPs) following transcranial magnetic stimulation and evoked spinal cord potentials following transcranial electrical stimulation (TE-ESCPs) were recorded in 14 patients with cervical myelopathy. MEPs were recorded from the biceps brachii (BB) and the abductor digit minimi (ADM) muscles. Central motor conduction time (CMCT) was also measured by subtracting the peripheral conduction time from the onset latencies of the MEPs. By comparing CMCT with TE-ESCPs, we studied the adequacy of the clinical diagnosis of the level of cervical myeiopathy using MEPs. In all 11 patients with abnormalities of TE-ESCPs at C3/4, C4/5 or C5/6 level, CMCT for the ADM were abnormally prolonged. In both patients with abnormalities at C3/4 level, CMCT for the BB were also prolonged. CMCT by MEPs from the BB and the ADM are valuable in the functional assessment of central motor pathway and may also be useful in the clinical diagnosis of cervical myelopathy.