Session Information
Date: Monday, October 8, 2018
Session Title: Parkinson's Disease: Neuroimaging And Neurophysiology
Session Time: 1:15pm-2:45pm
Location: Hall 3FG
Objective: To investigate whether cortical oscillations involved in sensorimotor and perceptual processes [alpha (8-12 Hz), low beta (13-20 Hz) and high beta (21-35 Hz)] change during interruptions of motor output in Parkinson’s disease (PD) patients with freezing of gait (FoG).
Background: FoG is a debilitating symptom in PD and can often be resistant to treatment. FoG is often triggered by narrow passageways and crowded rooms, and its incidence can be reduced by visual aids that prompt rhythmic stepping. Sensory influence on FoG suggests that sensory, perceptual and/or motor processes in the cortex may be intrinsically involved in FoG pathophysiology.
Methods: We recorded 64 channel electroencephalography in 10 PD patients (68 years old±6; disease duration: 9 years±5; UPDRS-III on medication: 27±9; UPDRS-III off medication: 31±8; levodopa equivalent dose: 880 mg±420) and 9 healthy controls (67 years old±6). Six patients had FoG confirmed by the New Freezing of Gait Questionnaire and neurologist assessment. While seated, participants manipulated foot pedals to walk through a virtual environment (VE). Participants completed 4 sets of 5 minutes walking within the VE. Doorways within the VE were used to trigger motor interruptions (MI). We also had participants intentionally stop to assess cortical activity unique to MI. Alpha, low beta and high beta were determined pre MI (-1200 to -600 ms), upon onset of MI (-300 to 300 ms), during MI (600 to 1200 ms), during an active state and upon intentionally stopping. Cortical activities were assessed in predetermined premotor/frontal (F1,Fz,F2,FC1,FCz,FC2), motor (C1,Cz,C2) and parietal (CP1,CPz,CP2,P1,Pz,P2) clusters.
Results: Patients with FoG experienced a total of 38 MI (mean duration 2.5 s). MI influenced alpha power within premotor/frontal (p=0.042; Onset MI Conclusions: Alpha and low-beta oscillations in motor areas may be important predictive signals of MI in patients with PD and FoG. Uniquely, the absence of high beta distinguishes MI from intentional stops. These findings may be useful for the development of closed-loop brain stimulation or biofeedback strategies to alleviate FoG. To cite this abstract in AMA style: « Back to 2018 International Congress MDS Abstracts - https://www.mdsabstracts.org/abstract/a-cortical-neural-signature-of-motor-interruption-in-patients-with-parkinsons-disease-and-freezing-of-gait/