The Subthalamic Nucleus Influences Visuospatial Attention in Humans

Abstract

Spatial attention is a lateralized feature of the human brain. Whereas the role of cortical areas of the nondominant hemisphere on spatial attention has been investigated in detail, the impact of the BG, and more precisely the subthalamic nucleus, on signs and symptoms of spatial attention is not well understood. Here we used unilateral deep brain stimulation of the subthalamic nucleus to reversibly, specifically, and intraindividually modify the neuronal BG outflow and its consequences on signs and symptoms of visuospatial attention in patients suffering from Parkinson disease. We tested 13 patients with Parkinson disease and chronic deep brain stimulation in three stimulation settings: unilateral right and left deep brain stimulation of the subthalamic nucleus as well as bilateral deep brain stimulation of the subthalamic nucleus. In all three stimulation settings, the patients viewed a set of pictures while an eye-tracker system recorded eye movements. During the exploration of the visual stimuli, we analyzed the time spent in each visual hemispace, as well as the number, duration, amplitude, peak velocity, acceleration peak, and speed of saccades. In the unilateral left-sided stimulation setting, patients show a shorter ipsilateral exploration time of the extrapersonal space, whereas number, duration, and speed of saccades did not differ between the different stimulation settings. These results demonstrated reduced visuospatial attention toward the side contralateral to the right subthalamic nucleus that was not being stimulated in a unilateral left-sided stimulation. Turning on the right stimulator, the reduced visuospatial attention vanished. These results support the involvement of the subthalamic nucleus in modulating spatial attention. Therefore, the subthalamic nucleus is part of the subcortical network that subserves spatial attention.

Brain activation underlying turning in Parkinson’s disease patients with and without freezing of gait: a virtual reality fMRI study

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Impact of Deep Brain Stimulation on Daily Routine Driving Practice in Patients with Parkinson’s Disease

“…Less sleepiness might be related to a postoperative reduction of medication. Positive effects of DBS on orientation could be possible, as recently DBS of the STN has been shown to modulate spatial attention [ 14 ]. One patient reported to have quit driving postoperatively due to impulsive and reckless driving, which might be related to stimulation, but also has been described as a dopaminergic side effect [ 15 ].…”

Deep Brain Stimulation for Parkinson’s disease changes perception in the Rubber Hand Illusion

“…We reasoned that improved processing of visual, somatosensory and temporal cues on stimulation [8][9][10][11][17][18][19] would lead to a more typical rejection of the RHI when visual-tactile cues are asynchronous. We expected to see this only in the asynchronous condition because, in our previous study, PD had no effect on illusion scores in the synchronous condition.…”