Spinal lipomas in children.

Spinal cord lipomas are a common cause of cord tethering that can lead to progressive neurological defects. The role of prophylactic surgery for spinal lipomas has recently been questioned. Between 1985 and 1999, 59 children underwent a total of 69 surgical procedures at the Birmingham Children's Hospital in Birmingham, UK. The spinal lipomas were classified into: 18 terminal, 17 transitional, 6 dorsal and 18 filum lipomas - including 12 who had a typical thickened filum terminale. At the first operation, 19 patients (32%) were asymptomatic, and 40 patients (68%) presented with symptoms. Surgical indications in the asymptomatic group included the presence of a dermal sinus tract or syrinx. Prophylactic surgery was undertaken in selected cases. The mean total follow-up for the group since the first surgical procedure was 61.8 months (range: 7.0-203.0 months). In the asymptomatic group, 26% of the patients had late neurological deterioration. Of the 14 patients with asymptomatic conus lipomas, 3 (21%) developed sphincter dysfunction and motor problems at long-term follow-up. In the symptomatic group, 68% improved, 20% remained unchanged, and 12% had late neurological deterioration. None of the 18 patients with symptomatic filum lipoma deteriorated postoperatively. However, 39% had bladder dysfunction, 54% had neuro-orthopaedic deformity, and only 15% returned to overall normal function at latest follow-up. Of the 27 patients with symptomatic conus lipomas, 67% improved, 15% remained stable, and 18% had late neurological deterioration. However, 74% had bladder dysfunction, 67% had neuro-orthopaedic deformity, and 45% had motor problems at long-term follow-up. Spinal lipomas can cause progressive neurological deficits irrespective of spinal untethering surgery. This study demonstrates that filum and conus lipomas have similar clinical presentation, but differ in their outcome following surgery. Filum lipomas are 'benign', for which surgery is safe and effective. Conus lipomas are more difficult to manage. When asymptomatic, our results suggest that prophylactic surgery does provide some protection from future neurological deterioration. When symptomatic, conus lipoma surgery is effective in stopping further deterioration. Improvement in neurological function can occur, but few patients return to normal overall function, and pre-existing sphincter dysfunction is not significantly altered by surgery.