Results of the section of the filum terminale in 20 patients with syringomyelia,scoliosis and Chiari malformation

Summary Background. Spinal cord traction caused by a tight filum terminale may be considered a pathogenic mechanism involved in the development of syringomyelia, the Chiari malformation (type I) and scoliosis. Section of the filum terminale is proposed as a useful surgical approach in these conditions.Methods. Between April 1993 and July 2003, a total of 20 patients (8 men and 12 women) with a mean age of 33.5 years underwent section of the filum terminale with or without opening of the dural sac through a standard sacrectomy. Eight patients suffered from scoliosis, 5 from syringomyelia, 2 from Chiari malformation and 5 with a combination of these conditions.Finding. After section of the filum terminale, patients with syringomyelia showed an early clinical improvement of dysaesthesia, thermo-anaesthesia, hypo-aesthesia and walking difficulties. Rising of the medullary conus was also observed. In patients with scoliosis, back pain improved dramatically and a curve reduction was noticed, although progression of the curve was observed in one case. In patients with Chiari malformation, headache, dysaesthesia and paraparesis disappeared.Conclusions. Section of the filum terminale is a useful strategy in the treatment of scoliosis, syringomyelia and the Chiari malformation, and offers a new aetiological basis for the understanding of these three disorders.