TY - JOUR
T1 - Cognitive effects of theta frequency bilateral subthalamic nucleus stimulation in Parkinson's disease
T2 - A pilot study
AU - Lam, Jordan
AU - Lee, Justin
AU - Williams, Marcus
AU - Cohn, Melanie
AU - Wilson, Melissa
AU - Mark, Catherine
AU - Esnaashari, Nasrin
AU - Petkus, Andrew
AU - Hui, Jennifer
AU - Feigenbaum, Danielle
AU - Liker, Mark
AU - Liu, Charles Y.
AU - Lee, Brian
AU - Lee, Darrin J.
N1 - Publisher Copyright:
© 2021 The Author(s)
PY - 2021/3/1
Y1 - 2021/3/1
N2 - Background: There is significant evidence for cognitive decline following deep brain stimulation (DBS). Current stimulation paradigms utilize gamma frequency stimulation for optimal motor benefits; however, little has been done to optimize stimulation parameters for cognition. Recent evidence implicates subthalamic nucleus (STN) theta oscillations in executive function, and theta oscillations are well-known to relate to episodic memory, suggesting that theta frequency stimulation could potentially improve cognition in Parkinson's disease (PD). Objective: To evaluate the acute effects of theta frequency bilateral STN stimulation on executive function in PD versus gamma frequency and off, as well as investigate the differential effects on episodic versus nonepisodic verbal fluency. Methods: Twelve patients (all males, mean age 60.8) with bilateral STN DBS for PD underwent a double-blinded, randomized cognitive testing during stimulation at (1) 130–135 Hz (gamma), (2) 10 Hz (theta) and (3) off. Executive functions and processing speed were evaluated using verbal fluency tasks (letter, episodic category, nonepisodic category, and category switching), color-word interference task, and random number generation task. Performance at each stimulation frequency was compared within subjects. Results: Theta frequency significantly improved episodic category fluency compared to gamma, but not compared to off. There were no significant differences between stimulation frequencies in other tests. Conclusion: In this pilot trial, our results corroborate the role of theta oscillations in episodic retrieval, although it is unclear whether this reflects direct modulation of the medial temporal lobe and whether similar effects can be found with more canonical memory paradigms. Further work is necessary to corroborate our findings and investigate the possibility of interleaving theta and gamma frequency stimulation for concomitant motor and cognitive effects.
AB - Background: There is significant evidence for cognitive decline following deep brain stimulation (DBS). Current stimulation paradigms utilize gamma frequency stimulation for optimal motor benefits; however, little has been done to optimize stimulation parameters for cognition. Recent evidence implicates subthalamic nucleus (STN) theta oscillations in executive function, and theta oscillations are well-known to relate to episodic memory, suggesting that theta frequency stimulation could potentially improve cognition in Parkinson's disease (PD). Objective: To evaluate the acute effects of theta frequency bilateral STN stimulation on executive function in PD versus gamma frequency and off, as well as investigate the differential effects on episodic versus nonepisodic verbal fluency. Methods: Twelve patients (all males, mean age 60.8) with bilateral STN DBS for PD underwent a double-blinded, randomized cognitive testing during stimulation at (1) 130–135 Hz (gamma), (2) 10 Hz (theta) and (3) off. Executive functions and processing speed were evaluated using verbal fluency tasks (letter, episodic category, nonepisodic category, and category switching), color-word interference task, and random number generation task. Performance at each stimulation frequency was compared within subjects. Results: Theta frequency significantly improved episodic category fluency compared to gamma, but not compared to off. There were no significant differences between stimulation frequencies in other tests. Conclusion: In this pilot trial, our results corroborate the role of theta oscillations in episodic retrieval, although it is unclear whether this reflects direct modulation of the medial temporal lobe and whether similar effects can be found with more canonical memory paradigms. Further work is necessary to corroborate our findings and investigate the possibility of interleaving theta and gamma frequency stimulation for concomitant motor and cognitive effects.
KW - Deep brain stimulation
KW - Hippocampus
KW - Language
KW - Neuromodulation
KW - Verbal fluency
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U2 - 10.1016/j.brs.2020.12.014
DO - 10.1016/j.brs.2020.12.014
M3 - Article
C2 - 33418095
AN - SCOPUS:85099633463
SN - 1935-861X
VL - 14
SP - 230
EP - 240
JO - Brain Stimulation
JF - Brain Stimulation
IS - 2
ER -