The Effect of Sensory Reweighting on Cortical Activity in Parkinson's Disease

Research Objectives: To compare cortical activity during the sensory organization of postural control between individuals with Parkinson's Disease and neurotypical older adults.

Design: The study involved measuring sensory integration of visual, somatosensory, and vestibular inputs related to postural balance. Six balance conditions were tested: (1) stable platform with eyes opened in a fixed virtual reality (VR) environment; (2) stable platform with dark VR environment; (3) stable platform with VR visual perturbation; Conditions 4 – 6 mimic the above conditions but on an unstable surface. Cortical activity was recorded with mobile electroencephalography (EEG). Linear mixed models were employed to examine the interaction between group and condition on frontal-theta power.

Setting: Laboratory

Participants: This cross-sectional study included 10 participants with PD (age: 72 ± 9; 3 women; Hoehn&Yahr: 2 [1.5 – 2.50]) and 11 controls (age: 70 ± 3; 4 women).

Interventions: None

Main Outcome Measures: Frontal-theta power

Results: The interaction effect of group by condition was significant (F = 7/53; p < 0.0001). Further, post-hoc analysis showed that there was a greater change in frontal-theta power from sitting to conditions 2 (p = 0.03), 4 (p < 0.0001), 5 (p = 0.005), and 6 (p = 0.049) compared to control.

Conclusions: Individuals with PD exhibit heightened cortical dynamics to sensory organization of postural control compared to controls. This increased frontal-theta power may reflect compensatory activity, particularly when vision and somatosensation are challenged.

Author(s) Disclosures: Sodiq Fakorede, Maryam Sadeghi, Thomas Bristow, Rajesh Pahwa, Kelly Lyons, Hannes Devos