A - 88 Parkinson's Disease and Deep Brain Stimulation (DBS) Device Settings: Effects of Amplitude, Pulse Width, and Frequency on Cognitive Performance.

Abstract

Frontal systems decline after DBS for Parkinson's disease has been consistently reported, with high frequency settings (>130Hz) correlating with decreased executive functioning and verbal fluency. The present study replicates and expands upon these findings. Six DBS recipients underwent standardized pre/post-surgical neuropsychological testing. Two-tailed T-tests assessed changes in cognitive scores. Correlational analyses explored relationships between cognitive scores and UPDRS, H&Y, and stimulator settings (amplitude, pulse width, and frequency). All participants underwent bilateral STN stimulation. Pre/post averages were: UPDRS (43.0 and 26.2) and H&Y (2.7 and 2.3) with average stimulator settings of amplitude (2.7V), pulse width (60.8μs), and frequency (151.7Hz). Pre/post neuropsychological testing revealed significant decline on the Behavioral Dyscontrol Scale (p = <0.01) with an average raw score decline of 3.17 points. All other cognitive scores showed non-significant improvement (p-value range = 0.22-0.89). H&Y change significantly correlated with semantic fluency (r = 0.96). UPDRS change significantly correlated with motoric processing speed (r = 0.91), semantic fluency (r = -0.93), and confrontation naming (r = -0.86). Stimulator amplitude significantly correlated with auditory attention (r = 0.82); simple planning (r = 0.96); and verbal memory (r = -0.86). Stimulator frequency significantly correlated with auditory attention (r = 0.87), simple planning (r = 0.97), and verbal memory (r = -0.96). Simulator pulse width was not significant. The study examines effects of bilateral STN stimulation on cognitive outcomes in patients with PD. A significant improvement in motor function was accompanied by a significant decline in performance on upper motor bilateral dexterity and inhibition. Correlation analysis shows the relationship between changes in cognition and motor function, as well as the correlation between stimulator settings and specific cognitive functions.