Original Article

THE EFFICACY OF INTRAOPERATIVE SPINAL CORD MONITORING DURING SURGERY FOR SPINAL STENOSIS

  • Mehmet Nurullah ERMİŞ
  • Can SOLAKOĞLU
  • Faik Murat ÜNSAL
  • Ferit MANGAL
  • Ömer POLAT
  • Özgür ŞENTÜRK

Received Date: 10.01.2012 Accepted Date: 05.03.2012 J Turk Spinal Surg 2012;23(2):122-127

Objectives:

To compare the findings of intraoperative spinal cord monitoring during posterior decompression and instrumentation for lumbar spinal stenosis and the clinical results obtained at the sixth month postoperatively.

Patients and methods:

Twenty patients, who received surgery in our clinic because of lumbar spinal stenosis and were monitored using an intraoperative spinal cord monitor between May 2011 and November 2011, were included in this study. The mean age of the patients was 69, and 10% were male (two patients) and 90% were female (18 patients). The preoperative radiological assessments of the patients were achieved using plain X-rays and MRI. The preoperative and postoperative clinical evaluations were performed with SF36, the Oswestry score and the Visual Analog Scale (VAS). Decompression was applied to all patients after completion of posterior spinal instrumentation during surgery. Interbody fusion was applied to one patient only. Transcortical Motor Evoked Potentials were used for neurological monitoring and the amplitude and latency changes were recorded. The correlation of the amplitude changes and the clinical results were evaluated.

Results:

The average preoperative VAS score of the patients was 8, which regressed to 1.8 postoperatively (p=0.0001). The average preoperative SF36 score was 29.5, which became 76.6 postoperatively (p=0.0001). The average preoperative Oswestry score was 65.5, and this regressed to 9.95 postoperatively (p=0.0001). A general rise in the amplitudes of the TkMEPs was observed during surgery in all of the patients. The TkMEP amplitudes increased more than 50% in 14 of the 20 patients, and increased less than 50% in six of the patients. The amount of stenosis present and the preoperative VAS scores of the patients were both found to be unrelated to the group of patients with a low amplitude increase (p=0.156, p=0.079).

Conclusion:

It was observed that the motor evoked potentials of all patients were raised during surgery, and this rise was found to correlate with the positive clinical results achieved postoperatively.

Keywords: Spinal stenosis, intraoperative neural monitoring, clinical results