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Parkinson’s Disease
Volume 2016, Article ID 6760243, 9 pages
Research Article

Deep Brain Stimulation Frequency of the Subthalamic Nucleus Affects Phonemic and Action Fluency in Parkinson’s Disease

1Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil
2Brain Institute of Rio Grande do Sul (InsCer), Porto Alegre, RS, Brazil
3Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil
4Federal University of Health Sciences from Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
5Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil

Received 5 August 2016; Accepted 20 October 2016

Academic Editor: Hélio Teive

Copyright © 2016 Valéria de Carvalho Fagundes et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Introduction. Deep brain stimulation of the subthalamic nucleus (STN-DBS) in Parkinson’s disease (PD) has been linked to a decline in verbal fluency. The decline can be attributed to surgical effects, but the relative contributions of the stimulation parameters are not well understood. This study aimed to investigate the impact of the frequency of STN-DBS on the performance of verbal fluency tasks in patients with PD. Methods. Twenty individuals with PD who received bilateral STN-DBS were evaluated. Their performances of verbal fluency tasks (semantic, phonemic, action, and unconstrained fluencies) upon receiving low-frequency (60 Hz) and high-frequency (130 Hz) STN-DBS were assessed. Results. The performances of phonemic and action fluencies were significantly different between low- and high-frequency STN-DBS. Patients showed a decrease in these verbal fluencies for high-frequency STN-DBS. Conclusion. Low-frequency STN-DBS may be less harmful to the verbal fluency of PD patients.