Does loss of spasticity matter? A 10-year follow-up after selective dorsal rhizotomy in cerebral palsy.

Aim: The aim of this study was to evaluate the long-term effects of selective dorsal rhizotomy (SDR) in children with cerebral palsy (CP).

Method: Nineteen children (four females, 15 males; mean age 4y 7mo, SD 1y 7mo) with bilateral spastic CP, were prospectively assessed at baseline and 18 months, 3 years, and 10 years after SDR. Assessments included the Modified Ashworth Scale for spasticity, the Gross Motor Function Measure 88 (GMFM-88) and the Wilson gait scale for ambulation, neurological investigations, and passive joint range of motion assessment. A 10-year retrospective chart review was added for orthopaedic surgery after SDR.

Results: Baseline muscle tone at the hip, knee, and ankle level displayed a high degree of spasticity that normalized after SDR. After 10 years there was a slight recurrence of spasticity at the knee and ankle. Joint range of motion declined from a maximum at 3 years after SDR to the 10-year follow-up. Median ambulatory status was best 3 years after SDR and then declined. The GMFM-88 score increased from the median baseline value of 51 to 66 (p=0.002) and 76 (p<0.001) at the initial follow-ups. After 10 years there was a decline in gross motor function with a reduction in the GMFM-88 score to 62 (p=0.022). Within 10 years, 16 out of 19 patients had a mean of three orthopaedic surgeries (SD 2.8), soft tissue surgery being the most common.

Interpretation: The spasticity-reducing effect of SDR, although pronounced, did not seem to improve long-term functioning or prevent contractures. This suggests that contracture development in CP is not mediated by spasticity alone.