摘要目的 分析经颅磁刺激运动诱发电位(motor evoked potentials,MEP)在腰椎管狭窄症临床评价中的应用价值.方法 23例腰椎管狭窄患者,男12例,女11例;年龄52～83岁,平均67.9岁.单纯腰椎管狭窄症11例,合并腰椎退变性滑脱12例.就诊时平均病程31.5个月(3个月～10年).出现单侧下肢症状者(疼痛或麻木、无力)9例,双下肢均出现者14例.所有患者均合并间歇性跛行,出现跛行前平均行走距离为302.1 m(3～1000 m).MRI中最狭窄节段的硬膜囊向积值(minimum cross-sectional area, MCSA)平均0.4 cm2(0.1～0.9 cm2).于患者双侧(足母)内收肌处记录经颅磁刺激MEP潜伏期(MEP latency,MEPLT),同时收集患者治疗前JOA评分、视觉模拟评分(VAS,包括腰痛,下肢、臀部痛及麻木程度).采用SPSS 12.0软件进行统计学分析.结果 MEPLT为(42.1±2.8)ms,JOA评分为(15.9±4.8)分.腰痛、下肢及臀部痛、下肢及臀部麻木感VAS分别为(6.0±2.9)分、(7.7±1.9)分、(7.3±3.0)分.MEPLT与步行距离、下肢症状类型及麻木VAS存在相关.步行距离＜500 m者MEPLT明显延长(t=3.529,P＜0.05).结论 MEPLT延长在腰椎管狭窄患者出现临床体征之前即可出现,MEP可有效反映患者的主观症状.

abstractsObjective To evaluate the clinical usefulness of assessing transcranial magnetic stimulated motor evoked potentials (MEP) in lumbar spinal stenosis (LSS).Methods Twenty-three LSS patients, consisting of 12 males and 11 females were enrolled.The mean age was 67.9 years(52-83 years).The average duration of symptoms was 31.5 months(3 months to 10 years).Twelve patients were associated with degenerative spondylolisthesis.Fourteen patients had bilateral and 9 patients had unilateral leg symptoms.The number of involved disc levels was one in 15 cases, two in 7 cases and three in 1 case.All patients were associated with neurogenic intermittent claudication (NIC).The mean walking distance of NIC and the minimal cross-sectional area (mCSA) of the dural sac was 302.1 m and 0.4 cm2, respectively.The preoperative data of MEP latency (MKPLT) recorded in both sides of adductor hallucis (AH), clinical symptoms, Japanese Orthopaedic Association (JOA) scores for low back pain, visual analogue scale (VAS) for back pain, leg pain and numbness were evaluated.Results The mean MEPLT were (42.1±2.8) ms.The mean JOA score, VAS scores for back pain, leg pain and numbness were 15.9±4.8, 6.0±2.9, 7.7±1.9 and 7.3±3.0, respectively.MEPLT was related to the walking distance (r=-0.455, P<0.05), limb symptoms (bilateral or unilateral symptoms, r=0.545, P<0.05) and VAS-numbness (r=0.605, P<0.05), but was not related to diagnosis (with/without degenerative spondylolisthesis), affected disc levels, duration of symptoms, JOA scores, VAS for back pain and leg pain.MEPLT was significantly delayed in patients who showed a walking distance less than 500 m (P<0.05).Conclusion MEP is useful in LSS assessment.It can reflect the subjective severity of motor disturbance and predict the neurological deficit prior to appearance.