Adaptive grip force is modulated by subthalamic beta activity in Parkinson's disease patients.

Lukas L Imbach,Heide Baumann-Vogel,Joachim Hermsdörfer,Johannes Sarnthein,Oguzkan Sürücü,Christian R Baumann

doi:10.1016/j.nicl.2015.09.010

Lukas L Imbach, Heide Baumann-Vogel + Show 4 more

Open Access

https://doi.org/10.1016/j.nicl.2015.09.010

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Abstract

IntroductionHealthy subjects scale grip force to match the load defined by physical object properties such as weight, or dynamic properties such as inertia. Patients with Parkinson's disease (PD) show an elevated grip force in dynamic object handling, but temporal aspects of anticipatory grip force control are relatively preserved. In PD patients, beta frequency oscillatory activity in the basal ganglia is suppressed prior to externally paced movements. However, the role of the subthalamic nucleus (STN) in anticipatory grip force control is not known.MethodsAfter implantation of deep brain stimulation (DBS) electrodes in the STN, PD patients performed adaptive and voluntary grip force tasks, while we recorded subthalamic local field potentials (LFP) and scalp EEG.ResultsDuring adaptive grip force control (Shake), we found event related desynchronization (ERD) in the beta frequency band, which was time-locked to the grip force. In contrast, during voluntary grip force control (Press) we recorded a biphasic ERD, corresponding to peak grip force and grip force release. Beta synchronization between STN and cortical EEG was reduced during adaptive grip force control.ConclusionThe time-locked suppression of beta oscillatory activity in the STN is in line with previous reports of beta ERD prior to voluntary movements. Our results show that the STN is involved in anticipatory grip force control in PD patients. The difference in the phasic beta ERD between the two tasks and the reduction of cortico-subthalamic synchronization suggests that qualitatively different neuronal network states are involved in different grip force control tasks.

Highlights

Healthy subjects scale grip force to match the load defined by physical object properties such as weight, or dynamic properties such as inertia
Direct evidence for the involvement of the subthalamic nucleus (STN) in grip force scaling has been obtained in Parkinson3s disease (PD) patients treated by deep brain stimulation (DBS), where pathologically elevated peak grip force could be normalized by chronic DBS (Wenzelburger et al, 2002)
The reduced coherence during the shaking task can be interpreted in light of the proposed neuroanatomical distinction between grip force scaling and temporal grip force control in anterior and posterior basal ganglia nuclei: for the voluntary pressing condition (Press) task we found higher cortico-STN coherence, indicating that this task is embedded in a cortico-basal ganglia network controlling for grip force parameterization

Summary

Introduction

Healthy subjects scale grip force to match the load defined by physical object properties such as weight, or dynamic properties such as inertia. Patients with Parkinson3s disease (PD) show an elevated grip force in dynamic object handling, but temporal aspects of anticipatory grip force control are relatively preserved. Healthy subjects precisely scale the applied grip force to match the load defined by physical object properties, such as weight and shape, as well as dynamic properties such as inertia (Prodoehl et al, 2009). Direct evidence for the involvement of the subthalamic nucleus (STN) in grip force scaling has been obtained in PD patients treated by deep brain stimulation (DBS), where pathologically elevated peak grip force could be normalized by chronic DBS (Wenzelburger et al, 2002)

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