Publication Date



Open access

Degree Type


Degree Name

Doctor of Philosophy (PHD)


Psychology (Arts and Sciences)

Date of Defense


First Committee Member

Philip McCabe - Committee Co-Chair

Second Committee Member

Bonnie Levin - Committee Co-Chair

Third Committee Member

Ray Winters - Committee Member

Fourth Committee Member

Edward Green - Committee Member

Fifth Committee Member

Matthias Siemer - Committee Member

Sixth Committee Member

Heather Katzen - Outside Committee Member


The current study examined cognitive effects of unilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) patients. Neuropsychological evaluations were conducted at baseline and follow-up. Data was collected from 28 unilateral STN DBS patients (15 English- and 13 Spanish-speaking), and 15 English-speaking matched PD control patients. English-speaking DBS patients demonstrated significant declines in verbal fluency and attention/executive function, whereas PD control patients did not experience significant cognitive decline. Cognitive performance did not differ based on side of DBS. Spanish-speaking DBS patients experienced significant declines in verbal fluency, confrontational naming and visuospatial abilities. Among Spanish-speaking DBS patients, older age and later age of disease onset predicted verbal fluency decline, even after controlling for education.


Neuropsychological Performance; Deep Brain Stimulation; Parkinson's Disease