Konno S, Goto S, Murakami M, Mochizuki M, Motegi H, Moriya H
Department of Orthopaedic Surgery, School of Medicine, Chiba University, Japan.
Spine (Phila Pa 1976). 1997 Mar 1;22(5):486-92. doi: 10.1097/00007632-199703010-00004.
Five cases of juvenile amyotrophy of the distal upper extremity were reviewed retrospectively to elucidate the pathophysiology of spinal cord dysfunction and the results of surgical management.
To clarify the pathogenesis of juvenile amyotrophy of the distal upper extremity and to present the results of a new surgical treatment.
Hirayama first reported this disorder in 1959. It is characterized by juvenile onset, slow progression, and involvement of the unilateral distal upper extremity. Recently, compression of the cervical spinal cord during neck flexion was implicated as a possible etiology of the disorder, but the exact etiology is still unknown. The value of surgical treatment for patients with juvenile amyotrophy of the distal upper extremity has not been established.
The clinical and radiographic characteristics of five patients with juvenile amyotrophy of the distal upper extremity were examined. All five patients were treated surgically with duraplasty in combination with posterior spinal fusion. Dynamic and computed tomographic myelography were performed before and after surgery. Intraoperative ultrasonography and conductive spinal cord evoked potentials were recorded before and after duraplasty. The surgical results and the histology of the resected dura were studied.
Myelograms taken with the neck in a neutral position showed that the spinal cord was flattened in all five patients. When the neck was flexed, the dura and the spinal cord were compressed further. Intraoperative ultrasonography during neck flexion revealed an anterior shift of the spinal cord and decreased spinal cord pulsation. Amplitude of the conductive spinal cord evoked potentials decreased with neck flexion but increased after dural incision. Histologically, the dura appeared abnormal in that it contained few elastic fibers without the normal wavy structure.
Juvenile amyotrophy of the distal upper extremity was characterized by inelastic dura that constricts and compresses the cervical spinal cord when the neck is in either a neutral or a flexed position. Abnormal dura appeared to be the cause of juvenile amyotrophy of the distal upper extremity. Duraplasty with spinal fusion are proposed as treatments.
对5例青少年上肢远端肌萎缩病例进行回顾性分析，以阐明脊髓功能障碍的病理生理学及手术治疗结果。
明确青少年上肢远端肌萎缩的发病机制，并展示一种新手术治疗的结果。
平山于1959年首次报道了这种疾病。其特点为青少年起病、进展缓慢且单侧上肢远端受累。最近，颈部屈曲时颈脊髓受压被认为可能是该疾病的病因，但确切病因仍不清楚。对于青少年上肢远端肌萎缩患者，手术治疗的价值尚未确立。
检查了5例青少年上肢远端肌萎缩患者的临床和影像学特征。所有5例患者均接受了硬脊膜成形术联合后路脊柱融合术。术前和术后进行了动态及计算机断层脊髓造影。硬脊膜成形术前和术后记录了术中超声及传导性脊髓诱发电位。研究了手术结果及切除硬脊膜的组织学情况。
颈部处于中立位时的脊髓造影显示，所有5例患者的脊髓均变扁。颈部屈曲时，硬脊膜和脊髓受到进一步压迫。颈部屈曲时的术中超声显示脊髓向前移位且脊髓搏动减弱。传导性脊髓诱发电位的波幅在颈部屈曲时降低，但在硬脊膜切开后升高。组织学上，硬脊膜表现异常，其弹性纤维少且无正常的波浪状结构。
青少年上肢远端肌萎缩的特点是硬脊膜缺乏弹性，在颈部处于中立位或屈曲位时会压迫颈脊髓。异常硬脊膜似乎是青少年上肢远端肌萎缩的病因。建议采用硬脊膜成形术联合脊柱融合术进行治疗。
