Cognitive function in children with primary dystonia before and after deep brain stimulation

Background: Dystonia is characterised by involuntary movements (twisting, writhing and jerking) and postures. The effects of deep brain stimulation (DBS) surgery on the motor aspect of primary dystonias have been well reported, however, there is a paucity of research investigating its impact on cognitive function, particularly in childhood dystonia. We performed a follow-up of cognitive function in children with primary dystonia following DBS pallidal surgery. Methods: Cognitive function was measured in a cohort of 13 children with primary or primary plus dystonia who had undergone DBS surgery using a retrospective case series design. Baseline pre-DBS neuropsychological measures were compared to scores obtained at least one year following DBS. Cognitive function was assessed using standardised measures of intellectual ability and memory. Results: All children demonstrated improvements with regard to dystonia reduction, as measured by the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). Overall, cognition remained stable following DBS in the majority of the cohort. Individual case analysis revealed improvements in some domains of cognitive function in eight members of the cohort and a deterioration of certain domains in four. Conclusion: Cognition largely remained stable in children with primary/primary plus dystonia following DBS surgery, although further research with a larger sample is necessary to explore this statistically. Notwithstanding the limitations of a small size, this preliminary data has potentially positive implications for the impact of DBS on cognitive functioning within a paediatric population. Crown Copyright (C) 2014 Published by Elsevier Ltd on behalf of European Paediatric Neurology Society. All rights reserved.