title: Randomized trial of deep brain stimulation for Parkinson disease: thirty-six-month outcomes; turning tables: should GPi become the preferred DBS target for Parkinson disease?
abstract: Weaver et al. and Tagliati mistakenly infer clinical equivalence between globus pallidus interna vs subthalamic nucleus deep brain stimulation based on failure to demonstrate statistically significant differences. A clinically meaningful-not statistically significant-difference in outcome should be decided a priori, after which the sample size necessary to have a reasonable probability of detecting the difference could be determined. (4) Fortunately, the study by Weaver et al. had sufficient sample size to demonstrate a 1-point difference in motor outcomes. However, such comparisons presume optimal management so as not to produce a "ceiling effect" that would obscure differences.
authors.forename: Erwin B
authors.initials: EB
authors.lastname: Montgomery
mesh_terms: D046690:Deep Brain Stimulation; D005260:Female; D006801:Humans; D008297:Male; D010300:Parkinson Disease / Q000503:physiopathology* / Q000628:therapy*; D011788:Quality of Life