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Background: Recently, therapeutic attempts to control motor choreatic hyperkinesia of Huntington's disease (HD) by means of pallidal deep brain stimulation (Gp-DBS) were successful. With respect to the clinical effects of Gp-DBS in juvenile hypokinetic-rigid HD (jHD; Westphal variant), only one single-case has been reported up to date. Oscillatory patterns of the Gp in jHD are not known., Objectives and Methods: This work aimed to analyse pallidal local field potential oscillations (LFP) in two patients with jHD treated with Gp-DBS. Safety data and clinical scores up to 12 months after DBS-electrode implantation were collected in the framework of a prospective trial (ClinicalTrials.gov; NCT00902889)., Results: Intraoperative LFP revealed local alpha and beta oscillations similar to those found in other movement disorders with akinetic rigid and dystonic presentation. Significant motor improvement was not found. There were no treatment-related complications or unresolved long-term adverse events., Conclusions: In spite of similar intraoperative LFP patterns of jHD with those of movement disorders benefitting from DBS, clinical results were not convincing in our patients, so that Gp-DBS in jHD cannot be generally recommended.

Expectation contributes to placebo and nocebo responses in Parkinson's disease (PD). While there is evidence for expectation-induced modulations of bradykinesia, little is known about the impact of expectation on resting tremor. Subthalamic nucleus (STN) deep brain stimulation (DBS) improves cardinal PD motor symptoms including tremor whereas impairment of verbal fluency (VF) has been observed as a potential side-effect. Here we investigated how expectation modulates the effect of STN-DBS on resting tremor and its interaction with VF. In a within-subject-design, expectation of 24 tremor-dominant PD patients regarding the impact of STN-DBS on motor symptoms was manipulated by verbal suggestions (positive [placebo], negative [nocebo], neutral [control]). Patients participated with (MedON) and without (MedOFF) antiparkinsonian medication. Resting tremor was recorded by accelerometry and bradykinesia of finger tapping and diadochokinesia were assessed by a 3D ultrasound motion detection system. VF was quantified by lexical and semantic tests. In a subgroup of patients, the effect of STN-DBS on tremor was modulated by expectation, i.e. tremor decreased (placebo response) or increased (nocebo response) by at least 10% as compared to the control condition while no significant effect was observed for the overall group. Interestingly, nocebo responders in MedON were additionally characterized by significant impairment in semantic verbal fluency. In contrast, bradykinesia was not affected by expectation. These results indicate that the therapeutic effect of STN-DBS on tremor can be modulated by expectation in a subgroup of patients and suggests that tremor is also among the parkinsonian symptoms responsive to placebo and nocebo interventions. While positive expectations enhanced the effect of STN-DBS by further decreasing the magnitude of tremor, negative expectations counteracted the therapeutic effect and at the same time exacerbated a side-effect often associated with STN-DBS. The present findings underscore the potency of patients' expectation and its relevance for therapeutic outcomes.

Expectation contributes to placebo and nocebo responses in Parkinson's disease (PD). Subthalamic nucleus (STN) deep brain stimulation (DBS) improves proximal more than distal movements whereas it impairs executive cognitive function such as verbal fluency (VF). We investigated how expectation modulates the pattern of motor improvement in STN-DBS and its interaction with VF. In a within-subject-design, expectation of 24 hypokinetic-rigid PD patients regarding the impact of STN-DBS on motor symptoms was manipulated by verbal suggestions (positive [placebo], negative [nocebo], neutral [control]). Patients participated with (MedON) and without (MedOFF) antiparkinsonian medication. Motor function was assessed by Unified Parkinson's Disease Rating Scale and quantitative kinematic analysis of proximal alternating hand and distal finger tapping. VF was quantified by lexical and semantic tests. In MedOFF, expectation significantly affected proximal but not distal movements resulting in better performance in the placebo than in the nocebo condition. Placebo responders with improvement of ≥25% were characterized by a trend for impaired lexical VF. These results indicate that positive motor expectations exert both motor placebo and cognitive nocebo responses by further enhancing the STN-DBS-effect on proximal movements and by impairing VF. The placebo response on motor performance resembles the clinically known STN-DBS-effect with stronger improvement in proximal than distal movements. The nocebo response on VF is likely due to implicit learning mechanisms associated with an expectation-induced placebo response on motor performance., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Background: Movement disorders in Huntington's disease are often medically refractive. The aim of the trial was assessment of procedure safety of deep brain stimulation, equality of internal- and external-pallidal stimulation and efficacy followed-up for 6 months in a prospective pilot trial. Methods: In a controlled double-blind phase six patients (four chorea-dominant, two Westphal-variant) with predominant movement disorder were randomly assigned to either the sequence of 6-week internal- or 6-week external-pallidal stimulation, or vice versa, followed by further 3 months chronic pallidal stimulation at the target with best effectside- effect ratio. Primary endpoints were changes in the Unified Huntington's Disease Rating Scale motor-score, chorea subscore, and total motor-score 4 (blinded-video ratings), comparing internal- versus external-pallidal stimulation, and 6 months versus baseline. Secondary endpoints assessed scores on dystonia, hypokinesia, cognition, mood, functionality/disability, and quality-of-life. Results: Intention-to-treat analysis of all patients (n=3 in each treatment sequence): Both targets were equal in terms of efficacy. Chorea subscores decreased significantly over 6 months (-5.3 (60.2%), p=0.037). Effects on dystonia were not significant over the group due to it consisting of three responders (>50% improvement) and three non-responders. Westphal patients did not improve. Cognition was stable. Mood and some functionality/disability and quality-of-life scores improved significantly. Eight adverse events and two additional serious adverse events - mostly internal-pallidal stimulationrelated - resolved without sequalae. No procedure-related complications occurred. Conclusion: Pallidal deep brain stimulation was demonstrated to be a safe treatment option for the reduction of chorea in Huntington's disease. Their effects on chorea and dystonia and on quality-of-life should be examined in larger controlled trials. [ABSTRACT FROM AUTHOR]