Transitions between repetitive tapping and upper limb freezing show impaired movement-related beta band modulation. Issue 10 (October 2020)

• Record Type: Journal Article
• Authors: Scholten, Marlieke; Schoellmann, Anna; Ramos-Murguialday, Ander; López-Larraz, Eduardo; Gharabaghi, Alireza; Weiss, Daniel
• Is Part Of: Clinical neurophysiology. Volume 131:Issue 10(2020:Oct.)
• Page Start: 2499
• Page End: 2507
• Publication Date: 2020-10
• Subjects: Parkinson's disease -- Repetitive finger movement -- Upper limb freezing -- Beta-band modulation -- Electrophysiology -- Sensorimotor processing; DBS deep brain stimulation -- FoG freezing of gait -- FOG-Q Freezing of Gait Questionnaire -- MMSE Mini-Mental Status Examination -- PD Parkinson's disease -- STFT short-time Fourier transform -- STN subthalamic nucleus -- ULF upper limb freezing -- UPDRS Unified Parkinson's Disease Rating Scale -- wPLI weighted phase lag index; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2020.05.037
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: We observed movement-related beta power modulation during finger movements in PD. This modulation was attenuated before upper limb freezing occurred. Synchronization increased between the fronto-parietal and the sensorimotor area. Abstract: Objective: Freezing phenomena in idiopathic Parkinson's disease (PD) constitute an important unaddressed therapeutic need. Changes in cortical neurophysiological signatures may precede a single freezing episode and indicate the evolution of abnormal motor network processes. Here, we hypothesize that the movement-related power modulation in the beta-band observed during regular finger tapping, deteriorates in the transition period before upper limb freezing (ULF). Methods: We analyzed a 36-channel EEG of 13 patients with PD during self-paced repetitive tapping of the right index finger. In offline analysis, we compared the transition period immediately before ULF ('transition') with regular tapping regarding movement-related power modulation and interregional phase synchronization. Results: From time-frequency analyses, we observed that the tap cycle related beta-band power modulation over the left sensorimotor area was diminished in the transition period before ULF. Furthermore, increased beta-band power was observed in the transition period compared to regular tapping centered over the left centro-parietal and right frontal areas. Phase synchronization between the left fronto-parietal areas and the left sensorimotor area was elevated during transition compared to regular tapping. Conclusion: Together, these results indicate that diminished beta band power modulation and increased phase synchronization precede ULF. Significance: We demonstrate that pathological cortical motor processing is present in the transition phase from regular tapping to an ULF episode.