Congratulations to Dr. Michael Okun on the publication of “Treatment-induced Changes in Cognitive-gait Interactions and Event-related EEG Potentials in Parkinson’s Disease.” This article appears in the April edition of Neurology.
Abstract
Objective:
To measure the effects of levodopa and deep brain stimulation (DBS) on response inhibition, gait speed, and event-related EEG potentials (ERPs) in people with Parkinson’s disease (PwPD) during performance of a response inhibition task while walking.
Background:
ERPs can non-invasively measure neural processes associated with cognitive-gait interactions. When performing a response inhibition task while walking, the first ERP component (N1) reflects early sensory-perceptual processes. The second component (N2) reflects subsequent “go/no-go” conflict monitoring and response selection processes. The third component (P3) reflects response inhibition processes. ERPs could reveal distinct mechanisms underlying disease and treatment-induced changes in cognitive-gait interactions, which could lead to improved outcomes in PwPD (e.g. freezing of gait, falls).
Design/Methods:
We measured response accuracy, treadmill-walking speed, and ERPs in PwPD as they completed a “go/no-go” response inhibition task while walking on a treadmill during four distinct levodopa/DBS treatment conditions (−levodopa/−DBS, −levodopa/+DBS, +levodopa/-DBS, +levodopa/+DBS). We used paired t-tests to evaluate differences among the treatment conditions with respect to response accuracy, treadmill-walking speed, and the mean amplitudes of the ERP components.
Results:
Ten PwPD (58–79 years-old, 2 females) had lower response accuracy, slower treadmill-walking speed, higher N1 mean amplitude, and lower N2 and P3 mean amplitudes during the −levodopa/-DBS condition. Response accuracy improved only during the +levodopa/+DBS condition (p=0.03). Walking speed improved during the −levodopa/+DBS, +levodopa/-DBS and +levodopa/+DBS conditions. The mean N1 amplitude improved during the +levodopa/-DBS condition (p<0.05). The mean N2 and P3 amplitudes improved during the −levodopa/+DBS condition (p<0.05).
Conclusions:
During a response inhibition task while walking, ERPs might reveal distinct mechanisms of treatment-induced changes in cognitive-gait interactions in PwPD. In these preliminary data, only the combination of levodopa and DBS was associated with improved response accuracy. Levodopa could improve the initial sensory-perceptual processes (N1) and DBS could improve subsequent cognitive processes associated with the task (N2 and P3).