頚動脈内膜剝離術時の経頭蓋MEPモニタリングで頚部過伸展による脊髄神経障害を回避し得た1例

抄録

We report a case in which spinal nerve disorder caused by cervical hyperextension during carotid endarterectomy was avoided by monitoring transcranial motor evoked potentials.

The patient was a 78-year-old man with severe asymptomatic stenosis of the right internal carotid artery in the neck. We recorded contralateral motor evoked potentials (MEPs) normally during carotid endarterectomy (CEA), but were unable to record ipsilateral MEPs. Preoperative magnetic resonance imaging (MRI) of the cervical cord revealed severe spinal canal stenosis and we concluded that recording MEPs was hindered because the cervical cord had been compressed by the hyperextension of the neck during CEA. When we repositioned the patient’s neck from the hyperextended position to its neutral position, we were able to record ipsilateral MEPs. Owing to the monitoring of transcranial MEPs, we avoided causing postoperative motor paralysis in the patient. The hyperextended position of the neck during CEA increases the risk of postoperative motor paralysis; this can be avoided by using transcranial MEP monitoring.