Epidemiology of tethered cord with meningomyelocele.

This paper describes the epidemiology of tethered cord syndrome and its etiologies and co-morbidities following initial repair of both meningomyeloceles and lipomeningomyelocele. A review of the pertinent literature and data from 654 cases of meningomyelocele and 118 cases of lipomeningomyelocele has been drawn from a computerized database, Patient Data Management System/fx. Only cases born since 1964 were analyzed for the etiologies, co-morbidities, spinal cord abnormalities detected by contrast studies or MRI and for significant symptoms and signs. Tethered cord symptoms were related to an attachment to a rigid tether for all 31 cases following lipomeningomyelocele repair but 62 (75%) of the 83 post meningomyelocele repair patients developed the symptoms of tethered cord. Causes other than, or in addition to, tethering included an obstructed cerebrospinal fluid shunt, syringohydromyelia, benign tumor and spinal cord hypoplasia. Quantitative differentiation between asymptomatic thin spinal cords and symptomatic spinal cord hypoplasia as well as between central canal enlargement and symptomatic syringohydromyelia could not be demonstrated. Collaborative, multi-center studies of larger numbers of patients are recommended.