椎旁体感诱发电位在神经根病变中的定位探讨

An approach to locate the paraspinal somatosensory evoked potential in radiculopathy

目的了解椎旁体感诱发电位(SSEP)在腰椎后路手术前后皮层电位潜伏期和波幅的改变,探讨椎旁SSEP在神经根病变中的定位价值。方法5例L4、5椎管狭窄症患者做术前、术后L4节段双侧椎旁SSEP,记录其P30潜伏期和波幅。10例L4、5单侧椎间盘突出伴有同侧临床腰腿痛症状的腰椎间盘突出症患者,做术前L4节段双侧椎旁SSEP及双侧胫神经SSEP,记录椎旁SSEP的P30潜伏期和胫神经SSEP的P40潜伏期。结果椎管狭窄症患者的椎旁SSEP手术前后P30潜伏期差异明显,术后较术前缩短,而P30波幅无明显差异。L4、5单侧椎间盘突出症患者双侧椎旁SSEP的P30潜伏期差异明显,双侧胫神经SSEP的P40潜伏期无明显差异。结论神经根病变可能引起椎旁SSEP的P30潜伏期延长,椎旁SSEP在神经根病变的定位上有参考价值。

Purpose To study the change of the latency and amplitude of the paraspinal somatosensory evoked potential（SSEP） before and after a dorsomedial approach lumbar surgery, and to explore the localization of paraspinal SSEP in radiculopathy. Methods Paraspinal SSEPs at the level L4 were elicited bilaterally at 5 lumbar spinal stenosis patients pre-operation and after-operation. The P30 latency and amplitude was recorded. Paraspinal SSEPs at the level L4 and tibial nerve SSEPs were elicited bilaterally at 10 unilateral intervertabral disc herniation patients. The P30 latency of paraspinal SSEP and P40 latency of tibial nerve SSEP were recorded. Results There was obvious difference of the P30 latency between pre-operation and after-operation of the spinal lumbar stenosis patients. The P30 latency shortened after the operation. But the difference of the P30 amplitude between pre-operation and afteroperation was not obvious. There was obvious difference of the P30 latency between the affected side and unaffected side of the unilateral intervertabral disc herniation patients. But the difference of the P40 latency between the affected side and unaffected side was not obvious. Conclusions These findings indicate that the P30 latency of paraspinal SSEP will prolong if nerve roots are affected. The paraspinal SSEPs may have some value on localization of radiculopathy.