PhD Scientific Days 2026

Poster Session 2.M - Neurosciences

Stimulation Selectively Blocks Subthalamic High Beta – Cortical High Gamma Coupling in Parkinson’s Disease

Name of the presenter

Berki, Ádám József

Institute/workplace of the presenter

Department of Neurology, Semmelweis University, Budapest, Hungary

Authors

Ádám József Berki¹, Hao Ding², Marcell Palotai¹, László Halász³, Loránd Erőss³, Gábor Fekete⁴, László Bognár⁴, Péter Barsi⁵, Andrea Kelemen¹, Borbála Jávor-Duray¹, Éva Pichner⁶, Muthuraman Muthuraman⁷, Gertrúd Tamás¹
1: Department of Neurology, Semmelweis University, Budapest, Hungary
2: Department of Neurology, Julius-Maximilians-Universität of Würzburg, Würzburg, Germany
3: Department of Neurosurgery and Neurointervention, Semmelweis University, Budapest, Hungary
4: Department of Neurosurgery, University of Debrecen, Debrecen, Hungary
5: Department of Neuroradiology, Medical Imaging Centre, Semmelweis University, Budapest, Hungary
6: Department of Neurology, Bajcsy-Zsilinszky Hospital and Clinic, Budapest, Hungary
7: Department of Neurology, Julius-Maximilians-Universität of Würzburg, Würzburg, Germany; Informatics for Medical Technology, University of Augsburg, Augsburg, Germany

Text of the abstract

Introduction
Subthalamic stimulation (STN-DBS) in Parkinson’s disease may operate along the hyperdirect pathway by suppressing the high beta connectivity between the STN and motor cortical areas and promoting high gamma motor cortical processing.
Aims
In this study, we examined how subthalamic beta activity shapes the pattern of cortical gamma rhythm and how STN-DBS influences this coupling.
Methods
Thirty-eight patients with akinetic-rigid Parkinson’s disease treated with bilateral STN-DBS were recruited. Four levels of contralateral stimulation were selected with improving bradykinesia based on kinematic testing (0: DBS OFF, 1-3). A high-density EEG was recorded at rest, and while patients drew self-paced and traced spirals on a digital tablet five times at the four selected stimulation levels. Using a beamformer inverse solution dynamic imaging for coherent sources, we analyzed phase-amplitude coupling (PAC) between subthalamic low (13-20 Hz) and high beta (21-30 Hz) and cortical (primary, supplementary motor, dorsal and ventral premotor cortex) low (31-60 Hz) and high gamma (61-100 Hz) frequency band pairs. The stimulation-induced slope values of PAC were correlated with the slopes of drawing speed.
Results
The PAC was higher when the high beta was the modulator, and the high gamma was the modulated band (p<0.001). The values did not differ between the subthalamo-cortical pathways (p=0.4) and during resting state and drawing tasks (p=0.055). When adjusting the stimulation level, subthalamic high beta–cortical high gamma value decreased the most at the fourth stimulation level (p<0.001), and its stimulation-induced decrease in subnetworks of the primary motor cortex and the dorsal premotor cortex correlated significantly with the increase in drawing speed.
Conclusion
Pathological subthalamic high beta activity abnormally drives high gamma motor cortical processing in Parkinson’s disease, and it is suppressed by STN-DBS. Stimulation-induced decrease in PAC along the hyperdirect pathways comprising the primary motor and the dorsal premotor cortex correlates with the improvement of bradykinesia during spiral drawing.

Funding
Supported by the 2025-2.1.1-EKÖP-2025-00014 University Research Scholarship Programme of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund.