Tamaki N, Shirataki K, Kojima N, Shouse Y, Matsumoto S
Department of Neurosurgery, Kobe University School of Medicine, Japan.
J Neurosurg. 1988 Sep;69(3):393-8. doi: 10.3171/jns.1988.69.3.0393.
Nine (15%) of 60 patients with repaired myelomeningocele exhibited late deterioration of neurological function with a tethered cord syndrome. Dense adhesions at the lowest laminae and at the site of previous repair were the most common findings at surgery. Postoperatively, 71% of the patients improved. Magnetic resonance (MR) imaging was performed in 29 of the 60 patients. Eight of these 29 patients exhibited a tethered cord syndrome. The MR images in all patients showed a low-lying conus fixed at the site of previous repair, irrespective of the presence or absence of a tethered cord syndrome. The MR images were classified into two groups depending upon the site of adhesions: Group A had potential sites of tethering at the ventral aspect of the last laminae and at the site of previous repair, and Group B showed the adhesion point only at the site of previous repair. Most patients with a tethered cord syndrome were found to be in Group A; conversely, most patients without the syndrome were in Group B. An enlarged low conus was seen in symptomatic patients more commonly than in those without this syndrome. It is concluded that the presence of adhesions specifically at the last laminae as well as a widened low-lying conus may be the cause of tethered cord syndrome in patients with repaired myelomeningoceles. A clear understanding of the tethering process and preoperative evaluation of potential sites of tethering, based on the MR findings, are very important for planning surgery. The release of adhesions at the lowest laminae by laminectomy appeared essential for improvement.
60例脊髓脊膜膨出修补术后患者中有9例（15%）出现了伴有脊髓栓系综合征的神经功能晚期恶化。手术中最常见的发现是最下层椎板及既往修补部位存在致密粘连。术后，71%的患者病情有所改善。60例患者中有29例行磁共振（MR）成像检查。这29例患者中有8例表现出脊髓栓系综合征。所有患者的MR图像均显示低位圆锥固定于既往修补部位，无论是否存在脊髓栓系综合征。根据粘连部位，MR图像分为两组：A组在最下层椎板腹侧及既往修补部位有潜在的栓系部位，B组仅在既往修补部位显示粘连点。大多数脊髓栓系综合征患者属于A组；相反，大多数无该综合征的患者属于B组。有症状的患者比无该综合征的患者更常见低位圆锥增大。结论是，特别是最下层椎板处存在粘连以及低位圆锥增宽可能是脊髓脊膜膨出修补术后患者发生脊髓栓系综合征的原因。基于MR表现，清楚了解栓系过程并对潜在栓系部位进行术前评估对手术规划非常重要。通过椎板切除术松解最下层椎板处的粘连似乎对病情改善至关重要。
