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Dopaminergic therapy in Parkinson's disease decreases cortical beta band coherence in the resting state and increases cortical beta band power during executive control.

George JS, Strunk J, Mak-McCully R, Houser M, Poizner H, Aron AR - Neuroimage Clin (2013)

Bottom Line: Dopaminergic medication reduced this coherence.Off medication increased beta band power over right frontal cortex for successful stopping and over bilateral sensorimotor cortex for going, especially for those patients who showed greater clinical improvement.Thus, medication reduced pathological coherence in beta band at rest and increased task related beta power for two potentially dissociable cortico-basal ganglia circuits.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of California San Diego, USA.

ABSTRACT
It is not yet well understood how dopaminergic therapy improves cognitive and motor function in Parkinson's disease (PD). One possibility is that it reduces the pathological synchronization within and between the cortex and basal ganglia, thus improving neural communication. We tested this hypothesis by recording scalp electroencephalography (EEG) in PD patients when On and Off medication, during a brief resting state epoch (no task), and during performance of a stop signal task that is thought to engage two partially overlapping (or different) frontal-basal-ganglia circuits. For resting state EEG, we measured pair-wise coherence between scalp electrodes in several frequency bands. Consistent with previous studies, in the Off medication state, those patients with the greatest clinical impairment had the strongest coherence, especially in the beta band, indicating pathological over-synchronization. Dopaminergic medication reduced this coherence. For the stop signal task, On vs. Off medication increased beta band power over right frontal cortex for successful stopping and over bilateral sensorimotor cortex for going, especially for those patients who showed greater clinical improvement. Thus, medication reduced pathological coherence in beta band at rest and increased task related beta power for two potentially dissociable cortico-basal ganglia circuits. These results support the hypothesis that dopaminergic medication in PD improves neural communication both at rest and for executive and motor function.

No MeSH data available.


Related in: MedlinePlus

Medication increases right frontal beta band power for stopping more in the high than low improvement group. Successful stop and all stop (successful and failed combined) trials for On vs Off medication for the high vs low improvement group comparison. There is a significant increase in beta power starting from the time of the stop signal and peaking around the time of SSRT. Time-frequency results are shown for the right frontal cluster (F8, FC6). Plots are generated from trials time-locked to the stop signal, corresponding to 0 ms here. T-score significance values are displayed as color. T-score significance values are displayed as color; t-score values reach significance at t13 = 2.16 (high vs low and On vs Off comparison). Significance at P < 0.05 is outlined in black indicating positive direction and red indicating negative direction. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
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f0025: Medication increases right frontal beta band power for stopping more in the high than low improvement group. Successful stop and all stop (successful and failed combined) trials for On vs Off medication for the high vs low improvement group comparison. There is a significant increase in beta power starting from the time of the stop signal and peaking around the time of SSRT. Time-frequency results are shown for the right frontal cluster (F8, FC6). Plots are generated from trials time-locked to the stop signal, corresponding to 0 ms here. T-score significance values are displayed as color. T-score significance values are displayed as color; t-score values reach significance at t13 = 2.16 (high vs low and On vs Off comparison). Significance at P < 0.05 is outlined in black indicating positive direction and red indicating negative direction. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Mentions: First, we examined behavior by using a mixed model repeated measures ANOVA to test the effect of medication On vs Off for high vs low improvement groups. Surprisingly, this did not reveal any significant main effects of group or interactions between group and medication (see Inline Supplementary Table S1). Nevertheless, there was a notable group difference in the EEG. We observed a stopping-related increase in beta and gamma band power in the right frontal cluster in the high-improvement group (especially when On medication), but less for the low-improvement group (Fig. 4A, B). Within the high improvement group, there was strongly elevated stopping-related beta and gamma for On vs. Off; however, this was not the case in the low improvement group (Fig. 4C). Finally, the interaction ‘high vs low’ improvement and ‘On vs Off’ medication was significant (P < 0.05) (Fig. 5) (This was estimated by performing an unpaired sample t-test of the On minus Off time-frequency maps of high and low improvement groups). Notably, this increase was not only for all stop trials taken together but also for the subset of successful stop trials, thus obviating the concern that it could have been driven by relative differences in desynchronization on failed stop trials or an effect of the movement itself. In addition, we compare this result for the successful stop trials for the right frontal cluster with the equivalent left frontal cluster (F7, FC5) (Inline Supplementary Fig. S3). We observed a greater increase in beta in the right frontal cluster compared to the left cluster around the time of stopping.


Dopaminergic therapy in Parkinson's disease decreases cortical beta band coherence in the resting state and increases cortical beta band power during executive control.

George JS, Strunk J, Mak-McCully R, Houser M, Poizner H, Aron AR - Neuroimage Clin (2013)

Medication increases right frontal beta band power for stopping more in the high than low improvement group. Successful stop and all stop (successful and failed combined) trials for On vs Off medication for the high vs low improvement group comparison. There is a significant increase in beta power starting from the time of the stop signal and peaking around the time of SSRT. Time-frequency results are shown for the right frontal cluster (F8, FC6). Plots are generated from trials time-locked to the stop signal, corresponding to 0 ms here. T-score significance values are displayed as color. T-score significance values are displayed as color; t-score values reach significance at t13 = 2.16 (high vs low and On vs Off comparison). Significance at P < 0.05 is outlined in black indicating positive direction and red indicating negative direction. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3814961&req=5

f0025: Medication increases right frontal beta band power for stopping more in the high than low improvement group. Successful stop and all stop (successful and failed combined) trials for On vs Off medication for the high vs low improvement group comparison. There is a significant increase in beta power starting from the time of the stop signal and peaking around the time of SSRT. Time-frequency results are shown for the right frontal cluster (F8, FC6). Plots are generated from trials time-locked to the stop signal, corresponding to 0 ms here. T-score significance values are displayed as color. T-score significance values are displayed as color; t-score values reach significance at t13 = 2.16 (high vs low and On vs Off comparison). Significance at P < 0.05 is outlined in black indicating positive direction and red indicating negative direction. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
Mentions: First, we examined behavior by using a mixed model repeated measures ANOVA to test the effect of medication On vs Off for high vs low improvement groups. Surprisingly, this did not reveal any significant main effects of group or interactions between group and medication (see Inline Supplementary Table S1). Nevertheless, there was a notable group difference in the EEG. We observed a stopping-related increase in beta and gamma band power in the right frontal cluster in the high-improvement group (especially when On medication), but less for the low-improvement group (Fig. 4A, B). Within the high improvement group, there was strongly elevated stopping-related beta and gamma for On vs. Off; however, this was not the case in the low improvement group (Fig. 4C). Finally, the interaction ‘high vs low’ improvement and ‘On vs Off’ medication was significant (P < 0.05) (Fig. 5) (This was estimated by performing an unpaired sample t-test of the On minus Off time-frequency maps of high and low improvement groups). Notably, this increase was not only for all stop trials taken together but also for the subset of successful stop trials, thus obviating the concern that it could have been driven by relative differences in desynchronization on failed stop trials or an effect of the movement itself. In addition, we compare this result for the successful stop trials for the right frontal cluster with the equivalent left frontal cluster (F7, FC5) (Inline Supplementary Fig. S3). We observed a greater increase in beta in the right frontal cluster compared to the left cluster around the time of stopping.

Bottom Line: Dopaminergic medication reduced this coherence.Off medication increased beta band power over right frontal cortex for successful stopping and over bilateral sensorimotor cortex for going, especially for those patients who showed greater clinical improvement.Thus, medication reduced pathological coherence in beta band at rest and increased task related beta power for two potentially dissociable cortico-basal ganglia circuits.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of California San Diego, USA.

ABSTRACT
It is not yet well understood how dopaminergic therapy improves cognitive and motor function in Parkinson's disease (PD). One possibility is that it reduces the pathological synchronization within and between the cortex and basal ganglia, thus improving neural communication. We tested this hypothesis by recording scalp electroencephalography (EEG) in PD patients when On and Off medication, during a brief resting state epoch (no task), and during performance of a stop signal task that is thought to engage two partially overlapping (or different) frontal-basal-ganglia circuits. For resting state EEG, we measured pair-wise coherence between scalp electrodes in several frequency bands. Consistent with previous studies, in the Off medication state, those patients with the greatest clinical impairment had the strongest coherence, especially in the beta band, indicating pathological over-synchronization. Dopaminergic medication reduced this coherence. For the stop signal task, On vs. Off medication increased beta band power over right frontal cortex for successful stopping and over bilateral sensorimotor cortex for going, especially for those patients who showed greater clinical improvement. Thus, medication reduced pathological coherence in beta band at rest and increased task related beta power for two potentially dissociable cortico-basal ganglia circuits. These results support the hypothesis that dopaminergic medication in PD improves neural communication both at rest and for executive and motor function.

No MeSH data available.


Related in: MedlinePlus