IMPORTANCE OF LATENCY OF MOTOR EVOKED POTENTIAL IN CERVICAL TUMOR

OBJECTIVE The purpose of this study is to assess the relevance of delayed latency of the motor evoked potential in a case of cervical tumor. METHODS Case report of a 35 years old female with progressive right hemiparesis (Medical Research Council Scale– 3/5) due to large infiltrative, contrast enhancing, intra-medullary tumor with an inferior cystic component spanning from the brainstem to C6. She underwent total resection of the tumor using intraoperative monitoring which showed normal motor evoked potentials on the left side and delayed motor evoked potentials of the right limbs from the beginning of the operation. RESULTS The tumor was completely resected and the motor evoked potentials during the removal and at the end of operation were stable (showing the same pattern of delayed latency on the right). Immediately after the intervention, the motor deficits of the right limbs were temporary aggravated (Medical Research Council Scale – 2/5). Subsequently, she recovered at 3 months. Pathology studies showed an anaplastic ependymoma. CONCLUSIONS The delayed latency of the motor evoked potentials related with cervical medullary tumor in some cases is not an useful tool for prediction of the post-operative motor deficit.