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

Abstract

ABBREVIATIONSBoNT-A Botulinum toxin type A MAS Modified Ashworth Scale ROM Range of motion SDR Selective dorsal rhizotomy 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. RESULTSBaseline 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. INTERPRETATIONThe 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.In children with cerebral palsy (CP), spasticity has often been assumed to be the main reason for functional limitations and development of contractures. Accordingly, many treatments are aimed at reducing spasticity. Interventions used to reduce spasticity are injections with botulinum toxin type A (BoNT-A), intrathecal baclofen therapy, oral drugs, orthopaedic surgery, and physiotherapy. 1 Selective dorsal rhizotomy (SDR) is a neurosurgical procedure where afferent excitatory nerve fibres emerging from the proprioceptors in the muscle spindles are cut where they enter the posterior root of the spinal cord, thereby reducing efferent excitation. The aim is to reduce spasticity and improve function. Reduction in spasticity has been shown for up to 5 years after SDR. 2There is conflicting evidence when tone-reducing therapies have been evaluated from a functional perspective, typically using gait or various assessments of gross motor function. 3,4 Thus studies have found moderate functional gains [5][6][7][8][9][10][11] or no positive functional outcomes. [12][13][14][15][16] However, only a subgroup of the studies has analysed in depth the possible correlation between a reduction in spasticity and improved function. Of these studies, only Love et al. 6 investigated this relationship and demonstrated a positive...

Outcomes after selective dorsal rhizotomy

“…The findings of Geyteenbek et al 2 await independent replication in a larger sample, with the additional non-verbal cognitive data to be confirmatory in nature. Yet this important hypothesis-generating work heightens our awareness of these diagnostic complexities and also challenges our use of diagnostic terminology.…”

“…finger pointing) responses from children with severe motor disorder. 1 Here we introduce the groundbreaking work of Geytenbeek et al 2 whose innovative computer-based instrument for low motor language testing (C-BiLLT), has helped confirm that at least a proportion of 'non-speaking' children with CP may have intact receptive communication skills. In particular, a number of children with dyskinetic CP in their sample had relatively preserved language comprehension.…”

“…[2][3][4][5][6] Except for the report by Hurvitz et al, which evaluated satisfaction with life, previous reports have focussed on the outcomes related to spasticity, range of motion, strength, and motor function. The current study is important, because it looks at outcomes beyond the usual motor performance measures that have been analyzed in prior studies.…”

“…2 Each term could arguably be associated with a different meaning. The lack of agreement and interchangeable use of terms for children who are non-verbal is understandable given the assessment challenges of determining why a particular child is 'non-verbal'; i.e.…”

“…is this due to severe motor planning or programming issues (apraxia), motor execution problems (anarthria or dysarthria), higher-level receptive language impairment, more generalized cognitive involvement, or a combination of any or all of these? Hence the innovative work of Geyteenbek et al 2 is not only a further step towards diagnostic precision, but also in improving labelling of these symptoms. Looking beyond CP, much of the broader neurodevelopmental literature is rife with lim-…”