Clinical Focus  |   May 2009
A Noninvasive Imaging Approach to Understanding Speech Changes Following Deep Brain Stimulation in Parkinson’s Disease
 
Author Affiliations & Notes
  • Shalini Narayana
    Research Imaging Center, The University of Texas Health Science Center, San Antonio
  • Adam Jacks
    Research Imaging Center, The University of Texas Health Science Center, San Antonio
  • Donald A. Robin
    Research Imaging Center, The University of Texas Health Science Center, San Antonio, and Honors College, The University of Texas, San Antonio
  • Howard Poizner
    Institute for Neural Computation, The University of California, San Diego
  • Wei Zhang
    Research Imaging Center, The University of Texas Health Science Center, San Antonio
  • Crystal Franklin
    Research Imaging Center, The University of Texas Health Science Center, San Antonio
  • Mario Liotti
    Simon Fraser University, Burnaby, British Columbia, Canada
  • Deanie Vogel
    Our Lady of the Lake University, San Antonio
  • Peter T. Fox
    Research Imaging Center, The University of Texas Health Science Center, San Antonio, and South Texas Veterans Health Care Center, San Antonio
  • Contact author: Shalini Narayana, Research Imaging Center, The University of Texas Health Science Center, San Antonio, 7703 Floyd Curl Drive MSC 6240, San Antonio, TX 78229-3900. E-mail: narayana@uthscsa.edu.
  • Adam Jacks is now at Texas State University—San Marcos.
    Adam Jacks is now at Texas State University—San Marcos.×
  • © 2009 American Speech-Language-Hearing AssociationAmerican Speech-Language-Hearing Association
Article Information
Special Populations / Older Adults & Aging / Speech, Voice & Prosody / Clinical Focus
Clinical Focus   |   May 2009
A Noninvasive Imaging Approach to Understanding Speech Changes Following Deep Brain Stimulation in Parkinson’s Disease
American Journal of Speech-Language Pathology, May 2009, Vol. 18, 146-161. doi:10.1044/1058-0360(2008/08-0004)
History: Received January 31, 2008 , Revised June 6, 2008 , Accepted October 13, 2008
 
American Journal of Speech-Language Pathology, May 2009, Vol. 18, 146-161. doi:10.1044/1058-0360(2008/08-0004)
History: Received January 31, 2008; Revised June 6, 2008; Accepted October 13, 2008
Web of Science® Times Cited: 24

Purpose: To explore the use of noninvasive functional imaging and “virtual” lesion techniques to study the neural mechanisms underlying motor speech disorders in Parkinson’s disease. Here, we report the use of positron emission tomography (PET) and transcranial magnetic stimulation (TMS) to explain exacerbated speech impairment following subthalamic nucleus deep brain stimulation (STN-DBS) in a patient with Parkinson’s disease.

Method: Perceptual and acoustic speech measures, as well as cerebral blood flow during speech as measured by PET, were obtained with STN-DBS on and off. TMS was applied to a region in the speech motor network found to be abnormally active during DBS. Speech disruption by TMS was compared both perceptually and acoustically with speech produced with DBS on.

Results: Speech production was perceptually inferior and acoustically less contrastive during left STN stimulation compared to no stimulation. Increased neural activity in left dorsal premotor cortex (PMd) was observed during DBS on. “Virtual” lesioning of this region resulted in speech characterized by decreased speech segment duration, increased pause duration, and decreased intelligibility.

Conclusions: This case report provides evidence that impaired speech production accompanying STN-DBS may result from unintended activation of PMd. Clinical application of functional imaging and TMS may lead to optimizing the delivery of STN-DBS to improve outcomes for speech production as well as general motor abilities.

Acknowledgments
This research was supported in part by grants from the National Institutes of Health, including National Institute of Neurological Disorders and Stroke Grants NS43738 to Peter T. Fox and NS36449 to Howard Poizner, and National Institute of Mental Health Grant MH60246 to Peter T. Fox. We offer sincere thanks to Dr. Charles Wilson of the University of Texas at San Antonio for thoughtful discussion and insightful comments on this work. Finally, we thank our patient for participation in this study.
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