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BackgroundReduced muscle strength is an independent risk factor for falls and related to postural instability in individuals with Parkinson’s disease. The ability of resistance training to improve postural control still remains unclear.ObjectiveTo compare resistance training with balance training to improve postural control in people with Parkinson’s disease.Methods40 patients with idiopathic Parkinson’s disease (Hoehn&Yahr: 2.5–3.0) were randomly assigned into resistance or balance training (2x/week for 7 weeks). Assessments were performed at baseline, 8- and 12-weeks follow-up: primary outcome: Fullerton Advanced Balance (FAB) scale; secondary outcomes: center of mass analysis during surface perturbations, Timed-up-and-go-test, Unified Parkinson’s Disease Rating Scale, Clinical Global Impression, gait analysis, maximal isometric leg strength, PDQ-39, Beck Depression Inventory. Clinical tests were videotaped and analysed by a second rater, blind to group allocation and assessment time.Results32 participants (resistance training: n = 17, balance training: n = 15; 8 drop-outs) were analyzed at 8-weeks follow-up. No significant difference was found in the FAB scale when comparing the effects of the two training types (p = 0.14; effect size (Cohen’s d) = -0.59). Participants from the resistance training group, but not from the balance training group significantly improved on the FAB scale (resistance training: +2.4 points, Cohen’s d = -0.46; balance training: +0.3 points, Cohen’s d = -0.08). Within the resistance training group, improvements of the FAB scale were significantly correlated with improvements of rate of force development and stride time variability. No significant differences were found in the secondary outcome measures when comparing the training effects of both training types.ConclusionsThe difference between resistance and balance training to improve postural control in people with Parkinson’s disease was small and not significant with this sample size. There was weak evidence that freely coordinated resistance training might be more effective than balance training. Our results indicate a relationship between the enhancement of rate of force development and the improvement of postural control.Trial RegistrationClinicalTrials.gov ID: NCT02253563

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ObjectiveDeep brain stimulation (DBS) of the ventral intermediate thalamic nucleus (Vim) is established for medically refractory severe essential tremor (ET), but long-term efficacy is controversial.MethodsTwenty patients with ET with DBS had standardized video-documented examinations at baseline, in the stimulation-on condition at short term (13.1 ± 1.9 months since surgery, mean ± SEM), and in the stimulator switched on and off (stim-ON/OFF) at long term; all assessments were done between 32 and 120 months (71.9 ± 6.9 months) after implantation. The primary outcome was the Tremor Rating Scale (TRS) blindly assessed by 2 trained movement disorder neurologists. Secondary outcomes were TRS subscores A, B, and C; Archimedes spiral score; and activities of daily living score. At long-term follow-up, tremor was additionally recorded with accelerometry. The rebound effect after switching the stimulator off was assessed for 1 hour in a subgroup.ResultsTremor severity worsened considerably over time in both in the nonstimulated and stimulated conditions. Vim-DBS improved the TRS in the short term and long term significantly. The spiral score and functional measures showed similar improvements. All changes were highly significant. However, the stimulation effect was negatively correlated with time since surgery (ρ = −0.78, p < 0.001). This was also true for the secondary outcomes. Only one-third of the patients had a rebound effect terminated 60 minutes after the stimulator was switched off. Long-term worsening of the TRS was more profound during stim-ON than in the stim-OFF condition, indicating habituation to stimulation.ConclusionVim-DBS loses efficacy over the long term. Efforts are needed to improve the long-term efficacy of Vim-DBS.Classification of evidenceThis study provides Class IV evidence that for patients with medically refractory severe ET, the efficacy of Vim-DBS severely decreases over 10 years.