患者男，２１岁。２０天前无明显诱因出现骶尾部疼痛伴右足背麻木。后逐渐出现大便不畅，小便排不尽，且右足背麻木逐渐向右小腿外侧发展，并出现右下肢无力。查体：右小腿外侧皮肤及右足背皮肤触觉、痛觉及温度觉减退，足背外翻不能，右足趾背伸不能，右侧跟腱反射消失。... Male patient, 21 years old. There was no obvious cause of pain in the sacrococcygeal appendix with numbness in the right foot 20 days earlier. After the gradual emergence of poor stool, urine row inexhaustible, and the right foot numbness gradually developed to the right lateral leg, and right lower limb weakness. Physical examination: skin tactility on the lateral skin of the right lower leg and back of the right foot, loss of pain and temperature sensation, loss of dorsiflexion of the foot, failure of dorsiflexion of the right toe, and disappearance of the right tendon reflex. ...