Improvement in upper limb function in children with dystonia following deep brain stimulation

Background: Childhood dystonia can severely impact upper limb function. Deep Brain Stimulation (DBS) has been shown to be effective in reducing dystonic symptoms in childhood. Functional recovery following DBS is however not well understood. Aims: To explore changes in upper limb function following DBS in paediatric dystonia.

Methods: Upper limb outcomes, using the Melbourne Assessment of Unilateral Upper Limb Function, are reported in 20 cases of childhood dystonia (unilateral n = 1, four limb n = 19) at 6 and 12 months following DBS.

Results: Improvement in at least in one upperlimb was seen in the majority of cases (n = 17, 85%) at 12 months following DBS. Deterioration of scores in both upper limbs was seen in 3 children with progressive disorders. Grouping the children aetiologically, a significant improvement in the dominant hand was obtained for the primary dystonia/dystonia-plus group at both six (p = 0.018) and twelve months (p = 0.012). In secondary dystonia due to a static disorder, improvement was also seen at 6 (p = 0.043) and 12 months (p = 0.046) in the non-dominant hand. No significant change was found in the group of children with progressive disorders.

Conclusions: DBS has the potential to alter upper limb function in children with primary and secondary dystonia. The dominant hand improved most in children with primary dystonias, with greater improvement in the non-dominant hand in secondary-static cases.