Türk Nöroşirürji Dergisi 1999 , Vol 9 , Num 1
Mehmet ZİLELİ1, Erdal ÇOŞKUN2, Berna ZİLELİ1
Ege Üniversitesi Tıp Fakültesi Nörolojik Cerrahi Anabilim Dalı, İzmir
2Pamukkale Üniversitesi Tıp Fakültesi Nörolojik Cerrahi Anabilim Dalı, Denizli
This study presents a clinical series with 32 cases that have evoked potentials monitoring during spine and spinal cord surgery. Clinical diagnosis was intramedullary tumors in 9 patients, intradural extramedullary tumors in 5 patients, extradural tumors in 5 patients, cervical spondylotic myelopathy in 6 patients, tethered cord syndrome in 6 patients, thoracic disc herniation in one patient. All of the patients were monitored with cortical SEPs (Somatosensory Evoked Potentials) by tibial and median nerve stimulation, 29 patients were addititonally monitored with spinal SEPs. In case the dura was opened, subdural recordings were done, otherwise epidural recordings were done. Intraoperative SEPs did not change in 21 patients, and worsened in 9 patients. Postoperative evaluation showed that clinical deficits did not change in 24 cases, progressed in one patient, deteriorated in 8 patients. We reported 2 false-negative, 3 false-positive, 6 true positive monitoring. SEPs with anal sphincter stimulation were more sensitive for monitoring of lesions in cauda and conus region. Since the surgeon reacted promptly to wave loss in one patient, SEPs were recovered during operation.In conclusion, monitoring of the patients with neurological deficits is harder than the patients without deficits such as scoliosis surgery. We noted serious fluctuations in already hampered base line activitiy of cortical SEPs in these patients. However, worsening or loss of spinal SEPs reflects the function of neurologic deficits, and should be considered as an absolute warning criteria. Anahtar Kelimeler : Spinal cord monitoring, somatosensory evoked potentials, spinal cord potentials, pudendal SEP