Аннотация:The internal segment of globus pallidus (GPi) is the most common target for surgicaltreatment of dystonia. Currently, low-frequency 3-12 Hz oscillations in the globus pallidusare considered the only potential biomarker of pathological activity in dystonia (Neumannet al., 2017). However, it remains unclear what rearrangements of the pattern temporalorganization are behind the emergence of these rhythms. It is assumed that the emergenceof simpler dynamics can be seen as a degradation of multifractal complexity.Previously, we have shown that dystonic BFMDRS symptom severity significantly correlated with the width and the shape of the multifractal spectrum (Semenova et al., 2021). Anincrease in severity scores was accompanied by a decrease of multifractal spectrum widthand rise of its asymmetry.In this study, we examined how these characteristics change during DBS. The data wererecorded during planned neurosurgical operations at the National Medical ResearchCenter for Neurosurgery N.N. Burdenko for implantation of stimulating electrodes (DBS).Four patients underwent externalization of LEAD electrodes for postoperative 16-channelrecording of local potentials (LFP) of the globus pallidus. We calculated the width andasymmetry of LFPs multifractal spectra estimated based on wavelet leaders at rest andduring stimulation.In all patients we observed substantial increase of multifractal spectrum width and restoration of its symmetry during DBS. We localized pallidal areas associated with the largestchange in the width of the multifractal spectrum in response to DBS. Using LEAD-DBSsoftware we modeled VTAs corresponding to the most efficacious DBS and looked athow these areas overlap. For all patients, the thesholded peak intensities of increase in themultifractal spectrum width was within the optimal VTA or significantly overlapped with it.We also found that the wider the spectrum became during the DBS, the better the clinicaleffect was observed in follow-up study.In sum, our data indicate the promise of using multifractal characteristics of pallidal neuronal activity as biomarkers of pathological activity in dystonia, as well as for evaluating andpredicting the clinical effect of DBS.This study was supported by Russian Science Foundation (23-25-00406).1) Neumann W, Horn A, Ewert S, et al. A localized pallidal physiomarker in cervical dystonia.Ann Neurol. 2017;82(6):912-924. doi:10.1002/ana.250952) Semenova U, Popov V, Medvednik R, Tomskiy A, Sedov A. Multifractal spectrum width ofpallidal activity correlates with dystonic severity [abstract]. Mov Disord. 2021; 36 (suppl 1)