RESUMEN
[Objective]To investigate the value of intra-operative somatosensory-evoked potential monitoring in surgery for thoracic spinal stenosis.[Method]Twenty-two patients with thoracic spinal stenosis underwent decompressive laminectomy surgery.The preoperative and intraoperative SPEs were recorded.The SEPs were analyzed with three indices:(1)SEPs wave pattern;(2)P40 latency;(3)P40-N50 amplitude.More than 50% decrease in SEPs amplitudes or more than 10% increase in latency was considered to be the warning threshold.[Result]Cases were classified into four groups according to preoperative SPEs wave pattern.Type Ⅰ inclued 2 cases whose SEPs monitoring had least meaning,and the spinal cord function remained unchanged postoperatively.4 cases with Type Ⅱ and the SEPs wave pattern were too unreliable to make analysis.Eleven cases in Type Ⅲ showed significant changes on SEPs,and most patients felt relief of symptom a week later.Type IV with 5 cases showed normal SEPs and all of them got well restored neurological function.[Conclusion]SEPs has good correlation with clinical outcomes.Its sensitivity,instant response and quantitative analysis make SEPs with great effectiveness in intraoperative monitoring on surgery of thoracic spinal stenosis.