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Stimulation of subthalamic nuclei restores a near normal planning strategy in Parkinson's patients.

Mirabella G, Iaconelli S, Modugno N, Giannini G, Lena F, Cantore G - PLoS ONE (2013)

Bottom Line: A fundamental function of the motor system is to gather key information from the environment in order to implement behavioral strategies appropriate to the context.In the former task patients had to perform speeded reaching movements to a peripheral target.In contrast, in the countermanding task participants had to perform the same reaches unless an infrequent and unpredictable stop-signal was shown during the reaction time (RT) indicating that they should withhold the ongoing action.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroscience, Istituto Neurologico Mediterraneo Neuromed, Pozzilli, IS, Italy. giovanni.mirabella@uniroma1.it

ABSTRACT
A fundamental function of the motor system is to gather key information from the environment in order to implement behavioral strategies appropriate to the context. Although several lines of evidence indicate that Parkinson's disease affects the ability to modify behavior according to task requirements, it is currently unknown whether deep brain stimulation (DBS) of the subthalamic nucleus (STN) affects context-related planning. To explore this issue, we asked 12 Parkinson's patients with bilateral STN DBS and 13 healthy subjects to execute similar arm reaching movements in two different paradigms: go-only and countermanding tasks. In the former task patients had to perform speeded reaching movements to a peripheral target. In contrast, in the countermanding task participants had to perform the same reaches unless an infrequent and unpredictable stop-signal was shown during the reaction time (RT) indicating that they should withhold the ongoing action. We compared the performance of Parkinson's patients in different DBS conditions. We found that patients with both DBS-ON behaved similarly to healthy subjects, in that RTs of no-stop trial increased while movement times (MTs) decreased with respect to those of go-only-trials. However, when both DBS were off, both RTs and MTs were longer in no-stop trials than in go-only trials. These findings indicate that bilateral DBS of STN can partially restore the appropriate motor strategy according to the given cognitive contexts.

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Reaction times (RTs) and movement times (MTs) for reaching movements across the populations of Parkinson’s patients and control subjects.A. Cumulative distribution of RTs (solid lines) and MTs (dotted lines) of healthy subjects (n = 13) for go-only (grey) and no-stop trials (black). B. Cumulative distributions of RTs (solid lines) and MTs (dotted lines) of DBS patients (n = 12) in DBS-ON and DBF-OFF conditions for both go-only (grey lines) and no-stop (black lines) trials. For each condition the p-value of Kolmogorov-Smirnov test is given, both for RTs and for MTs. C. Histograms of average RTs of no-stop and go-only trials in DBS-ON and DBF-OFF conditions. Bars represent the standard error of the mean. D. Histograms of average MTs of no-stop and go-only trials in each DBS-ON and DBF-OFF conditions. Bars represent the standard error of the mean.
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pone-0062793-g003: Reaction times (RTs) and movement times (MTs) for reaching movements across the populations of Parkinson’s patients and control subjects.A. Cumulative distribution of RTs (solid lines) and MTs (dotted lines) of healthy subjects (n = 13) for go-only (grey) and no-stop trials (black). B. Cumulative distributions of RTs (solid lines) and MTs (dotted lines) of DBS patients (n = 12) in DBS-ON and DBF-OFF conditions for both go-only (grey lines) and no-stop (black lines) trials. For each condition the p-value of Kolmogorov-Smirnov test is given, both for RTs and for MTs. C. Histograms of average RTs of no-stop and go-only trials in DBS-ON and DBF-OFF conditions. Bars represent the standard error of the mean. D. Histograms of average MTs of no-stop and go-only trials in each DBS-ON and DBF-OFF conditions. Bars represent the standard error of the mean.

Mentions: Figure 3 and Table 3 illustrate the main findings of the present study. Data from single participants are combined to create cumulative distributions of RTs and of MTs of go-only versus no-stop trials at the population level (Fig. 3A and B). As expected, the two experimental paradigms had opposite effects on RTs and MTs of healthy controls [13]. In fact, they exhibited longer RTs and shorter MTs in no-stop trials than in go-only trials (Fig. 3A; Kolmogorov–Smirnov test, ps<0.0001). Qualitatively, PD patients in the DBS-ON condition showed a similar pattern (Kolmogorov–Smirnov test, ps<0.0001; Fig. 3B, left panels). However, in the DBS-OFF condition both RTs and MTs were longer in no-stop trials than in go-only trials (Kolmogorov–Smirnov test, ps<0.0001; Fig. 3B, right panel).


Stimulation of subthalamic nuclei restores a near normal planning strategy in Parkinson's patients.

Mirabella G, Iaconelli S, Modugno N, Giannini G, Lena F, Cantore G - PLoS ONE (2013)

Reaction times (RTs) and movement times (MTs) for reaching movements across the populations of Parkinson’s patients and control subjects.A. Cumulative distribution of RTs (solid lines) and MTs (dotted lines) of healthy subjects (n = 13) for go-only (grey) and no-stop trials (black). B. Cumulative distributions of RTs (solid lines) and MTs (dotted lines) of DBS patients (n = 12) in DBS-ON and DBF-OFF conditions for both go-only (grey lines) and no-stop (black lines) trials. For each condition the p-value of Kolmogorov-Smirnov test is given, both for RTs and for MTs. C. Histograms of average RTs of no-stop and go-only trials in DBS-ON and DBF-OFF conditions. Bars represent the standard error of the mean. D. Histograms of average MTs of no-stop and go-only trials in each DBS-ON and DBF-OFF conditions. Bars represent the standard error of the mean.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3643906&req=5

pone-0062793-g003: Reaction times (RTs) and movement times (MTs) for reaching movements across the populations of Parkinson’s patients and control subjects.A. Cumulative distribution of RTs (solid lines) and MTs (dotted lines) of healthy subjects (n = 13) for go-only (grey) and no-stop trials (black). B. Cumulative distributions of RTs (solid lines) and MTs (dotted lines) of DBS patients (n = 12) in DBS-ON and DBF-OFF conditions for both go-only (grey lines) and no-stop (black lines) trials. For each condition the p-value of Kolmogorov-Smirnov test is given, both for RTs and for MTs. C. Histograms of average RTs of no-stop and go-only trials in DBS-ON and DBF-OFF conditions. Bars represent the standard error of the mean. D. Histograms of average MTs of no-stop and go-only trials in each DBS-ON and DBF-OFF conditions. Bars represent the standard error of the mean.
Mentions: Figure 3 and Table 3 illustrate the main findings of the present study. Data from single participants are combined to create cumulative distributions of RTs and of MTs of go-only versus no-stop trials at the population level (Fig. 3A and B). As expected, the two experimental paradigms had opposite effects on RTs and MTs of healthy controls [13]. In fact, they exhibited longer RTs and shorter MTs in no-stop trials than in go-only trials (Fig. 3A; Kolmogorov–Smirnov test, ps<0.0001). Qualitatively, PD patients in the DBS-ON condition showed a similar pattern (Kolmogorov–Smirnov test, ps<0.0001; Fig. 3B, left panels). However, in the DBS-OFF condition both RTs and MTs were longer in no-stop trials than in go-only trials (Kolmogorov–Smirnov test, ps<0.0001; Fig. 3B, right panel).

Bottom Line: A fundamental function of the motor system is to gather key information from the environment in order to implement behavioral strategies appropriate to the context.In the former task patients had to perform speeded reaching movements to a peripheral target.In contrast, in the countermanding task participants had to perform the same reaches unless an infrequent and unpredictable stop-signal was shown during the reaction time (RT) indicating that they should withhold the ongoing action.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroscience, Istituto Neurologico Mediterraneo Neuromed, Pozzilli, IS, Italy. giovanni.mirabella@uniroma1.it

ABSTRACT
A fundamental function of the motor system is to gather key information from the environment in order to implement behavioral strategies appropriate to the context. Although several lines of evidence indicate that Parkinson's disease affects the ability to modify behavior according to task requirements, it is currently unknown whether deep brain stimulation (DBS) of the subthalamic nucleus (STN) affects context-related planning. To explore this issue, we asked 12 Parkinson's patients with bilateral STN DBS and 13 healthy subjects to execute similar arm reaching movements in two different paradigms: go-only and countermanding tasks. In the former task patients had to perform speeded reaching movements to a peripheral target. In contrast, in the countermanding task participants had to perform the same reaches unless an infrequent and unpredictable stop-signal was shown during the reaction time (RT) indicating that they should withhold the ongoing action. We compared the performance of Parkinson's patients in different DBS conditions. We found that patients with both DBS-ON behaved similarly to healthy subjects, in that RTs of no-stop trial increased while movement times (MTs) decreased with respect to those of go-only-trials. However, when both DBS were off, both RTs and MTs were longer in no-stop trials than in go-only trials. These findings indicate that bilateral DBS of STN can partially restore the appropriate motor strategy according to the given cognitive contexts.

Show MeSH
Related in: MedlinePlus