Neural correlates of STN DBS-induced cognitive variability in Parkinson disease.
BACKGROUND
Although deep brain stimulation of the subthalamic nucleus (STN DBS) in Parkinson disease (PD) improves motor function, it has variable effects on working memory (WM) and response inhibition (RI) performance. The purpose of this study was to determine the neural correlates of STN DBS-induced variability in cognitive performance.


METHODS
We measured bilateral STN DBS-induced blood flow changes (PET and [(15)O]-water on one day) in the supplementary motor area (SMA), dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and right inferior frontal cortex (rIFC) as well as in exploratory ROIs defined by published meta-analyses. STN DBS-induced WM and RI changes (Spatial Delayed Response and Go-No-Go on the next day) were measured in 24 PD participants. On both days, participants withheld PD medications overnight and conditions (OFF vs. ON) were administered in a counterbalanced, double-blind manner.


RESULTS
As predicted, STN DBS-induced DLPFC blood flow change correlated with change in WM, but not RI performance. Furthermore, ACC blood flow change correlated with change in RI but not WM performance. For both relationships, increased blood flow related to decreased cognitive performance in response to STN DBS. Of the exploratory regions, only blood flow changes in DLPFC and ACC were correlated with performance.


CONCLUSIONS
These results demonstrate that variability in the effects of STN DBS on cognitive performance relates to STN DBS-induced cortical blood flow changes in DLPFC and ACC. This relationship highlights the need to further understand the factors that mediate the variability in neural and cognitive response to STN DBS.
Campbell
M C
MC
Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, United States.
Karimi
M
M
Weaver
P M
PM
Wu
J
J
Perantie
D C
DC
Golchin
N A
NA
Tabbal
S D
SD
Perlmutter
J S
JS
Hershey
T
T
D000368:Aged; D000704:Analysis of Variance; D001931:Brain Mapping; D003072:Cognition Disorders / Q000209:etiology*; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D005260:Female; D006179:Gyrus Cinguli / Q000098:blood supply / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology / Q000528:radiation effects; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000628:therapy*; D049268:Positron-Emission Tomography; D017397:Prefrontal Cortex / Q000098:blood supply / Q000000981:diagnostic imaging; D020531:Subthalamic Nucleus / Q000000981:diagnostic imaging / Q000502:physiology / Q000528:radiation effects*