tDCS of the Primary Motor Cortex to Improve Implicit Motor Sequence Learning in Parkinson's Disease

Summary

Implicit motor sequence learning (IMSL) is a form of cognitive function that is known to be directly associated with impaired motor function in Parkinson's disease (PD). Research in healthy young participants shows the potential for transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique, over the primary motor cortex (M1) to enhance IMSL. tDCS has direct effects on the underlying cortex, but also induces distant (basal ganglia) network effects - hence its potential value in PD, a prime model of basal ganglia dysfunction. To date, however, only null-effects have been reported in persons with PD. In the present study, the investigators will investigate the potential of tDCS delivered over M1 to enhance IMSL, as measured by the Serial Reaction Time task, in persons with PD. The investigators will determine immediate effects that may occur concurrently with the application of tDCS but also short-term (five minutes post-tDCS) and long-term (one week post-tDCS) consolidation effects, as previous studies suggest that tDCS exerts its beneficial effects on IMSL in a consolidation phase rather than in an acquisition phase. Establishing possible consolidation effects is of a particular interest, as long-term effects are vital for the successful functional rehabilitation of persons with PD.

Conditions

• Parkinson Disease
• Parkinson
• Healthy

Interventions

DEVICE

1x1 Low Intensity Transcranial Direct Current Stimulation (tDCS)

tDCS will be delivered through a pair of identical square rubber electrodes (size 35 cm2), placed in rectangular saline-soaked sponges. For the stimulation of M1, electrodes will be placed over C3 or C4 according to the 10-20 EEG system, matching with the M1 contralateral to the performing dominant hand. The reference electrode will be positioned on F1 or F2, ipsilateral to the dominant hand. The current stimulation will be slowly ramped up from 0 mA to 2 mA in one minute. For the anodal tDCS condition, this intensity will be maintained for the duration of the SRT-task (approximately 20 minutes). This will result in a current density of 0,057 mA/cm2. For the sham tDCS condition - unbeknown to the subject - stimulation will be gradually decreased towards 0 mA immediately after the one-minute ramp-up. During the last block of the SRT-task, this gradual ramping-up and -down of the current stimulation will be repeated to optimize the process of blinding of participants.

Sponsors & Collaborators

• Vrije Universiteit Brussel

  lead OTHER

Principal Investigators

• Natacha Deroost, PhD · Vrije Universiteit Brussel - Brain Body and Cognition Research Group

• Kris Baetens, PhD · Vrije Universiteit Brussel - Brain Body and Cognition Research Group

• Chris Baeken, PhD, MD · University Ghent

• Frank Van Overwalle, PhD · Vrije Universiteit Brussel - Brain Body and Cognition Research Group

• Eva Swinnen, PhD · Vrije Universiteit Brussel - Rehabilitation Research Group

• Mahyar Firouzi, PhD · Vrije Universiteit Brussel - Brain Body and Cognition Research Group

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

CROSSOVER

Eligibility

Min Age

55 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2020-10-11

Primary Completion

2022-08-31

Completion

2022-08-31

Countries

• Belgium

Study Locations