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Parkinson Disease: HELP
Articles by Dennis Chen
Based on 2 articles published since 2010
(Why 2 articles?)
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Between 2010 and 2020, Dennis Chen wrote the following 2 articles about Parkinson Disease.
 
+ Citations + Abstracts
1 Article Coordinate-based lead location does not predict Parkinson's disease deep brain stimulation outcome. 2014

Nestor, Kelsey A / Jones, Jacob D / Butson, Christopher R / Morishita, Takashi / Jacobson, Charles E / Peace, David A / Chen, Dennis / Foote, Kelly D / Okun, Michael S. ·Department of Neurology, University of Florida, Center for Movement Disorders and Neurorestoration, McKnight Brain Institute, Gainesville, Florida, United States of America; Department of Neurosurgery, University of Florida, Center for Movement Disorders and Neurorestoration, McKnight Brain Institute, Gainesville, Florida, United States of America. · Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, United States of America. · Department of Neurology, Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America. · Department of Neurosurgery, University of Florida, Center for Movement Disorders and Neurorestoration, McKnight Brain Institute, Gainesville, Florida, United States of America. · Department of Neurology, University of Florida, Center for Movement Disorders and Neurorestoration, McKnight Brain Institute, Gainesville, Florida, United States of America. ·PLoS One · Pubmed #24691109.

ABSTRACT: BACKGROUND: Effective target regions for deep brain stimulation (DBS) in Parkinson's disease (PD) have been well characterized. We sought to study whether the measured Cartesian coordinates of an implanted DBS lead are predictive of motor outcome(s). We tested the hypothesis that the position and trajectory of the DBS lead relative to the mid-commissural point (MCP) are significant predictors of clinical outcomes. We expected that due to neuroanatomical variation among individuals, a simple measure of the position of the DBS lead relative to MCP (commonly used in clinical practice) may not be a reliable predictor of clinical outcomes when utilized alone. METHODS: 55 PD subjects implanted with subthalamic nucleus (STN) DBS and 41 subjects implanted with globus pallidus internus (GPi) DBS were included. Lead locations in AC-PC space (x, y, z coordinates of the active contact and sagittal and coronal entry angles) measured on high-resolution CT-MRI fused images, and motor outcomes (Unified Parkinson's Disease Rating Scale) were analyzed to confirm or refute a correlation between coordinate-based lead locations and DBS motor outcomes. RESULTS: Coordinate-based lead locations were not a significant predictor of change in UPDRS III motor scores when comparing pre- versus post-operative values. The only potentially significant individual predictor of change in UPDRS motor scores was the antero-posterior coordinate of the GPi lead (more anterior lead locations resulted in a worse outcome), but this was only a statistical trend (p<.082). CONCLUSION: The results of the study showed that a simple measure of the position of the DBS lead relative to the MCP is not significantly correlated with PD motor outcomes, presumably because this method fails to account for individual neuroanatomical variability. However, there is broad agreement that motor outcomes depend strongly on lead location. The results suggest the need for more detailed identification of stimulation location relative to anatomical targets.

2 Article Swallowing outcomes following unilateral STN vs. GPi surgery: a retrospective analysis. 2014

Troche, Michelle S / Brandimore, Alexandra E / Foote, Kelly D / Morishita, Takashi / Chen, Dennis / Hegland, Karen W / Okun, Michael S. ·Department of Speech, Language, and Hearing Sciences, University of Florida, PO Box 117420, Gainesville, FL, 32611, USA, michi81@ufl.edu. ·Dysphagia · Pubmed #24652582.

ABSTRACT: The adverse effects of deep brain stimulation (DBS) surgery on swallowing could potentially exacerbate the natural deterioration of airway protection associated with Parkinson's disease (PD) degeneration and increase the incidence of aspiration pneumonia and associated death. There are no studies that compare swallowing outcomes associated with subthalamic nucleus (STN) versus globus pallidus interna (GPi) DBS surgery; therefore, we completed a retrospective study comparing swallowing outcomes in a cohort of patients with PD who underwent unilateral DBS surgery in either the STN or GPi. A chart review was completed to identify all patients with a diagnosis of PD who received videofluoroscopic swallowing evaluations before DBS and after unilateral DBS in the STN or GPi. The retrospective search yielded 33 patients (STN = 14, GPi = 19) with idiopathic PD who met the inclusion criteria. Mean penetration-aspiration (PA) scores did not change significantly for participants who underwent GPi surgery (z = -.181, p = .857), but mean PA scores significantly worsened for participants who underwent STN DBS (z = -2.682, p = .007). There was a significant improvement in Unified PD Rating Scale (UPDRS) scores off medication before surgery, to off medication and on stimulation after surgery for both groups (F = 23.667, p < .001). Despite the limitations of a retrospective analysis, this preliminary study suggests that unilateral STN DBS may have an adverse effect on swallowing function, while unilateral GPi DBS does not appear to have a similar deleterious effect. This study and other future studies should help to elucidate the mechanisms underpinning the effects of DBS on swallowing function.