Objective: The aim of the current study is to distinguish and characterize subthalamic (STN) neuronal activity specifically related to dystonia in Parkinson’s disease (PD) patients.
Background: Although dystonia and PD are each well described, PD patients with co-occurring focal dystonia remain understudied. Previous studies in PD patients with dystonia reported increased low-frequency power in STN local field potentials (LFPs) during movement, when dystoniс symptoms worsen, similar to that observed in primary dystonia [1]. We observed a similar pattern in resting-state STN activity in PRKN PD patients with dystonia [2]. However, prior studies examined PD cohorts that included patients both with and without tremor, rather than specifically addressing dystonia as an isolated hyperkinetic symptom.
Method: In this pilot study, we compared 4 PD patients and 4 PD patients with dystonia, all with the akinetic-rigid form, who underwent DBS surgery. We analyzed 71 (PD-only) vs 106 (PD+dystonia) single units (SUA) and 34 vs 36 LFP recordings, all obtained from the STN of awake patients at rest. ISI-based metrics, hierarchical clustering, and spectral analysis were used for data analysis. AI tools were used exclusively to improve the language of the abstract.
Results: We found no uniform differences in STN SUA between the PD-only and PD+dystonia patients. None of the ISI-based metrics reached significance, likely due to inter-patient variability in SUA. In contrast, LFP spectral analysis revealed a significant difference between the PD-only and PD+dystonia groups in the 9-14 Hz band (p<0.01, FDR-corrected Mann-Whitney test), commonly associated with dystonia. Unexpectedly, the median spectral power in this band was lower in the PD+dystonia group than in the PD-only group. In addition, median spectral power in the 22-27 Hz band, typically associated with PD symptoms, tended to be higher in the PD+dystonia group than in the PD-only group.
Conclusion: Our results imply that dystonia-related neuronal characteristics in akinetic-rigid PD patients are heterogeneous and challenging to interpret. Differences detected at the LFP level, but not in spiking activity, may reflect mechanisms beyond the STN, highlighting the need for further investigation.
The study was funded by Russian Science Foundation (RSF), project number 22-15-00344-P.
References: [1] Olson, J.W., Nakhmani, A., Irwin, Z.T., Edwards, L.J., Gonzalez, C.L., Wade, M.H., Black, S.D., Awad, M.Z., Kuhman, D.J., Hurt, C.P., Guthrie, B.L. and Walker, H.C. (2022), Cortical and Subthalamic Nucleus Spectral Changes During Limb Movements in Parkinson’s Disease Patients with and Without Dystonia. Mov Disord, 37: 1683-1692. https://doi.org/10.1002/mds.29057
[2] Pavlovsky, P., Golik, A., Gamaleya, A., Tomskiy, A., Shulskaya, M., Sedov, A., Slominsky, P. and Belova, E. (2026), Altered subthalamic alpha-beta oscillations in PRKN-associated early onset Parkinson’s disease in relation to off-dystonia. Parkinsonism Relat Disord. 143:108165. https://doi.org/10.1016/j.parkreldis.2025.108165
To cite this abstract in AMA style:
A. Golik, P. Pavlovsky, A. Gamaleya, A. Tomskiy, A. Sedov, E. Belova. STN Neuronal Activity Shows Complex and Patient-Dependent Differences in Akinetic-Rigid Parkinson’s Disease With and Without Dystonia [abstract]. Mov Disord. 2026; 41 (suppl 1). https://www.mdsabstracts.org/abstract/stn-neuronal-activity-shows-complex-and-patient-dependent-differences-in-akinetic-rigid-parkinsons-disease-with-and-without-dystonia/. Accessed October 1, 2026.« Back to 2026 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/stn-neuronal-activity-shows-complex-and-patient-dependent-differences-in-akinetic-rigid-parkinsons-disease-with-and-without-dystonia/