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.