患者男,38岁。因“左下肢疼痛2年余”入院。2年前患者无明显诱因左下肢外侧酸痛,以体位变化或行走时明显,无大小便障碍。体检:L4~5局部脊柱旁压痛阳性,双下肢温觉无明显减退,双下肢肌力Ⅴ级,肌张力正常,腱反射正常,肛门括约肌无松弛,无“脑膜刺激征”。无家族性遗传病史。MRI:L Male patient, 38 years old. Because of “left leg pain more than 2 years” admission. 2 years ago, the patient had no obvious incentive outside the left lower extremity soreness, change in position or walking obvious, no urine disorder. Physical examination: L4 ~ 5 local spine next to tenderness positive, no lower limb temperature sensory decline, lower limb muscle strength grade Ⅴ, normal muscle tone, tendon reflexes normal, no anal sphincter relaxation, no “meningeal irritation sign.” No family history of genetic disease. MRI: L