The Effect of Unilateral Subthalamic Nucleus Deep Brain Stimulation on Contralateral Subthalamic Nucleus Local Field Potentials

Abstract

Objectives Unilateral subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson's disease (PD) improves ipsilateral symptoms, but how this occurs is not well understood. We investigated whether unilateral STN DBS suppresses contralateral STN beta activity in the local field potential (LFP), since previous research has shown that activity in the beta band can correlate with the severity of contralateral clinical symptoms and is modulated by DBS. Materials and Methods We recorded STN LFPs from 14 patients who underwent bilateral STN DBS for PD. Following a baseline recording, unilateral STN stimulation was delivered at therapeutic parameters while LFPs were recorded from the contralateral (unstimulated) STN. Results Unilateral STN DBS suppressed contralateral beta power (p = 0.039, relative suppression = −5.7% ± [SD] 16% when averaging across the highest beta peak channels; p = 0.033, relative suppression = −5.2% ± 13% when averaging across all channels). Unilateral STN DBS produced a 17% ipsilateral (p = 0.016) and 29% contralateral (p = 0.002) improvement in upper limb hemi‐body bradykinesia‐rigidity (UPDRS‐III, items 3.3‐3.6). The ipsilateral clinical improvement and the change in contralateral beta power were not significantly correlated. Conclusions Unilateral STN DBS suppresses contralateral STN beta LFP. This indicates that unilateral STN DBS modulates bilateral basal ganglia networks. It remains unclear whether this mechanism accounts for the ipsilateral motor improvements.

Toward therapeutic electrophysiology: beta-band suppression as a biomarker in chronic local field potential recordings

“…Recent technical investigations into likelihood of ECG contaminations 48 showed the predominance of ECG artifacts with left-sided implants and laterality of IPG placement should be taken into consideration in future for patients with chronic sensing devices. However, although previous aDBS studies have suggested independent oscillatory activity between hemispheres 49 , other studies have demonstrated beta coupling between subthalamic nuclei 5 , 50 and even suppression of oscillatory activity in the contralateral STN during unilateral DBS 51 . Hence, even unilateral robust DBS signals might be a sufficient basis for aDBS algorithms.…”

Preliminary Experience with a Four-Lead Implantable Pulse Generator for Deep Brain Stimulation

“…Clinical evidence has shown that unilateral stimulation of the STN can produce bilateral therapeutic affects [22], albeit with reduced efficacy compared to bilateral stimulation in the contralateral side [23, 24]. Electrophysiologic recordings of the unstimulated STN revealed modulated firing rates that suggest bilateral projections of the STN [25, 26] or possible inter-connectivity [27]. This additionally may be important in epilepsy where duty cycle stimulation programming and its effect on neural networks may benefit from cross-talk between bilateral leads [28, 29].…”

Comparison of subthalamic unilateral and bilateral theta burst deep brain stimulation in Parkinson’s disease

“…Intraoperative, unilateral, high-frequency electrical STN stimulation induced and suppressed tremor in both forearms in a frequency-dependent manner, accompanied by bilateral, subthalamic, oscillatory local field potential changes ( Liu et al, 2002 ). Unilateral STN-DBS suppressed contralateral STN beta LFPs ( Hasegawa et al, 2020 ). In the animal model, neural subthalamic single unit firing rates were decreased bilaterally after unilateral STN-DBS in dopamine-depleted rats, indicating cross-talk between bilateral STN neurons ( Shi et al, 2006 ).…”