两个问题，麻烦大家看一下

Case Description

A 45-year-old man presents with a 5-day history of right leg pain. He describes the pain as acute in onset with constant numbness with overlying pins and needles burning involving his anterior shin. He has noticed that the toes on his right foot have been dragging on the foor, causing him to trip. One day prior to presentation, he developed similar but milder symptoms on his left leg. He denies history of low back pain, trauma, rashes, joint pain, constitutional symptoms, polydipsia, polyuria, or history of hepatitis. There is no history of prolonged kneeling, squatting, leg crossing, or prolonged immobility. He has no medical problems, takes no medications, and has no family history of neurologic problems. He does not use any tobacco, alcohol, or any illicit substances.

一、 病例描述

男性，45岁，右小腿疼痛5天就诊，他描述疼痛为急性发作，伴持续麻木以及胫前刺痛和针灼样痛，他注意到自己的右脚趾一直在地板上拖着（不能抬足），这容易导致他绊倒。在右小腿症状的前一天，他的左小腿也出现了类似的但较轻的症状。他否认有腰痛、创伤、皮疹、关节痛、全身症状、多饮、多尿或肝炎等病史。无长时间下跪、下蹲、盘腿或制动史。他无任何健康问题，未服用任何药物，也无神经系统疾病的家族史。他不吸烟、不喝酒、不吸毒。

His general examination reveals intact peripheral pulses and no joint swelling nor decreased range of motion. His strength examination is notable for right foot weakness in dorsifexion and eversion, with preserved strength of foot inversion, knee fexion and extension, and hip abduction. His sensory examination reveals diminished sensation over the anterolateral shin and dorsum of the foot, sparing high thigh or posterior lower leg. There are similar but milder examination fndings on his left leg. There are no asymmetries in refexes and his plantar responses are downgoing. He walks with a steppage quality to his gait on his left.

全身检查显示，周围脉搏完好，无关节肿胀也无活动范围下降。肌力检查显示右足背屈和外翻无力明显，足内翻、膝屈伸和髋外展的力量正常。感觉检查显示胫前外侧和足背感觉减弱，大腿上部或小腿后部感觉正常。左小腿检查结果类似，但程度较轻。反射对称，足底反应是足下垂。走路时左腿跨阈步态。

Prior to examination, his differential diagnosis for a neurologic cause of leg pain and foot drop depended on the area of the nervous system involved. The absence of upper motor neuron signs (increased tone, hyper-refexia, and upgoing plantar response), a sensory level, and bowel/bladder involvement suggests that the site of the lesion is at or distal to the anterior horn cell of the spinal cord. The presence of sensory symptoms excludes pure motor disorders such as motor neuron diseases, neuromuscular junction, or muscle disorders. The most probable site of disease is at the nerve roots, plexus, or peripheral nerves.

在检查前，其小腿疼痛和足下垂的神经源性病因的鉴别诊断取决于所累及的神经系统的区域。无上运动神经元体征（肌张力增高、反射亢进和足底上翘反应）、无感觉障碍平面以及也无直肠/膀胱受累提示病变部位在脊髓前角细胞或远端。感觉症状排除了纯运动障碍性疾病（如运动神经元病、神经肌接头或肌肉疾患）的可能，最可能的病变部位是神经根、神经丛或周围神经。

1.He has noticed that the toes on his right foot have been dragging on the foor、his plantar responses are downgoing、foot drop

这3个都是指足下垂？对吗

2.The absence of 也指 a sensory level, and bowel/bladder involvement 吧？无感觉障碍平面以及也无直肠/膀胱受累 吧？