Dissociation of motor symptoms during deep brain stimulation of the subthalamic nucleus in the region of the internal capsule - PubMed (original) (raw)

Dissociation of motor symptoms during deep brain stimulation of the subthalamic nucleus in the region of the internal capsule

Weidong Xu et al. Exp Neurol. 2011 Apr.

Abstract

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) can be an effective treatment for the motor symptoms of Parkinson's disease. The therapeutic benefits are voltage-dependent and, in many cases, limited by the appearance of side effects, including muscle contractions. We have observed a number of clinical cases where improvements in rigidity were accompanied by a worsening of bradykinesia. Considering the anatomic position of STN and current approaches to implantation of the DBS lead, we hypothesized that this dissociation of motor symptoms arises from activation of pyramidal tract fibers in the adjacent internal capsule. The objective of this study was to assess the physiological basis for this dissociation and to test our hypothesis that the underlying etiology of this paradox is activation of fibers of the internal capsule. The effect of STN DBS at 80% of motor threshold for each of the four contacts was evaluated for its effect on rigidity, bradykinesia, and akinesia in a single primate with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism. Consistent with our observations in humans, this near-threshold stimulation was found to improve rigidity while bradykinesia and akinesia worsened. Worsening bradykinesia in the face of improvement of other motor signs in Parkinson's disease (PD) patients is suggestive of activation of pyramidal tract (PT) fibers during stimulation. This phenomenon may occur without overt muscle contraction and improved rigidity.

Copyright © 2010 Elsevier Inc. All rights reserved.

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Figures

Figure 1

Figure 1

Top Row: The effect of stimulus amplitude, as a percentage of MT, on clinical ratings for, from left to right, rigidity (blue), akinesia (green) and bradykinesia (red). MIDDLE ROW: The effect of stimulation at 80% of MT on the clinical ratings of rigidity, akinesia and bradykinesia for each of the four contacts of the DBS lead. BOTTOM ROW: Percentage change in motor performance on the reach and retrieval task is shown for each contact of the DBS lead when stimulation was delivered at 80% of MT; For all graphs, effects are expressed as percentage improvement in ratings relative to the off condition, with positive values representing improved behavior relative to baseline. (* p < 0.012)

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References

    1. Ashby P, Kim YJ, Kumar R, Lang AE, Lozano AM. Neurophysiological effects of stimulation through electrodes in the human subthalamic nucleus. Brain. 1999;122 (Pt 10):1919–1931. - PubMed
    1. Ashby P, Rothwell JC. Neurophysiologic aspects of deep brain stimulation. Neurology. 2000;55:S17–20. - PubMed
    1. Bejjani B, Damier P, Arnulf I, Bonnet AM, Vidailhet M, Dormont D, Pidoux B, Cornu P, Marsault C, Agid Y. Pallidal stimulation for Parkinson’s disease. Two targets? Neurology. 1997;49:1564–1569. - PubMed
    1. Bergman H, Raz A, Feingold A, Nini A, Nelken I, Hansel D, Ben-Pazi H, Reches A. Physiology of MPTP tremor. Mov Disord. 1998;13(Suppl 3):29–34. - PubMed
    1. Berman BD, Starr PA, Marks WJ, Jr, Ostrem JL. Induction of bradykinesia with pallidal deep brain stimulation in patients with cranial-cervical dystonia. Stereotact Funct Neurosurg. 2009;87:37–44. - PMC - PubMed

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