Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Neurological disability
RCT	40 people aged 14 to 75 years with primary segmental (16 people) or generalised dystonia (24 people) for a minimum of 5 years	Improvement in Burke–Fahn–Marsden Dystonia (BFMD) Rating Scale total movement score 3 months –15.8 with neurostimulation –1.4 with sham stimulation Change in BFMD score for movement from baseline; possible range of scores of 0 to 120	P <0.001	Effect size not calculated	neurostimulation
RCT	40 people aged 14 to 75 years with primary segmental (16 people) or generalised dystonia (24 people) for a minimum of 5 years	Improvement in BFMD Rating Scale disability score 3 months –3.9 with neurostimulation –0.8 with sham stimulation Change in BFMD score for disability from baseline; possible range of scores of 0 to 30	P <0.001	Effect size not calculated	neurostimulation