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

NCT04606979 | Unknown

• 1 other identifier: B1432020000012
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief 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

Keywords

Parkinson Disease; Transcranial Direct Current Stimulation; tDCS; Serial Reaction Time Task; Sequence Learning; Procedural Learning; Implicit Learning; Implicit Motor Sequence Learning

Outcome Measures

Primary Outcomes (2)

• Serial Reaction Time task: Sequence-Specific Learning Effect (during and following active tDCS)

  The Serial Reaction Time task (SRT-task) will be employed, using E-Prime® software. In a typical SRT task, a target (e.g. black dot) is presented in one of four horizontal locations on a computer screen. Participants are asked to react to the target location by pressing a spatially compatible response key. They are not informed that the order of target locations follows a sequence predetermined by the experimenter. Participants are trained on the sequence in several blocks of trials, e.g.: 7 blocks of 100 trials. Typically, reaction times (RTs) decrease with practice, which is referred to as a general learning effect and constitutes the non-sequence-specific learning component of IMSL. Crucially, RTs increase when the sequence is inconspicuously replaced by a random sequence and decrease again when the predetermined sequence is reintroduced. The latter is referred to as the sequence-specific learning effect and is calculated by subtracting the mean RTs of the adjacent sequel blocks.

  Changes in Sequence-Specific Learning Effect will be assessed between: (baseline) during active tDCS; (short-term) 5-minutes post active tDCS; (long-term) 1 week post active tDCS

• Serial Reaction Time task: Sequence-Specific Learning Effect (during and following sham tDCS)

  The Serial Reaction Time task (SRT-task) will be employed, using E-Prime® software. In a typical SRT task, a target (e.g. black dot) is presented in one of four horizontal locations on a computer screen. Participants are asked to react to the target location by pressing a spatially compatible response key. They are not informed that the order of target locations follows a sequence predetermined by the experimenter. Participants are trained on the sequence in several blocks of trials, e.g.: 7 blocks of 100 trials. Typically, reaction times (RTs) decrease with practice, which is referred to as a general learning effect and constitutes the non-sequence-specific learning component of IMSL. Crucially, RTs increase when the sequence is inconspicuously replaced by a random sequence and decrease again when the predetermined sequence is reintroduced. The latter is referred to as the sequence-specific learning effect and is calculated by subtracting the mean RTs of the adjacent sequel blocks.

  Changes in Sequence-Specific Learning Effect will be assessed between: (baseline) during sham tDCS; (short-term) 5-minutes post sham tDCS; (long-term) 1 week post sham tDCS

Secondary Outcomes (2)

• Serial Reaction Time task: General Learning Effect (during and following active tDCS)

  Changes in General Learning Effect will be assessed between: (baseline) during active tDCS; (short-term) 5-minutes post active tDCS; (long-term) 1 week post active tDCS

• Serial Reaction Time task: General Learning Effect (during and following sham tDCS)

  Changes in General Learning Effect will be assessed between: (baseline) during sham tDCS; (short-term) 5-minutes post sham tDCS; (long-term) 1 week post sham tDCS

Study Arms (4)

Parkinson Disease - Group 1a - Active tDCS first

EXPERIMENTAL

Half of the subjects with PD will receive active (anodal, real) tDCS in the first session. Following cross-over and a three-week washout-period, this half of the subjects with PD will receive sham (placebo) tDCS.

Device: 1x1 Low Intensity Transcranial Direct Current Stimulation (tDCS)

Parkinson Disease - Group 1b - Sham tDCS first

SHAM COMPARATOR

Half of the subjects with PD will receive sham tDCS in the first session. Following cross-over and a three-week washout-period, this half of the subjects with PD will receive active (anodal, real) tDCS.

Device: 1x1 Low Intensity Transcranial Direct Current Stimulation (tDCS)

Healthy Controls - Group 2a - Active tDCS first

EXPERIMENTAL

Half of the healthy controls will receive active (anodal, real) tDCS in the first session. Following cross-over and a three-week washout-period, this half of the healthy controls will receive sham (placebo) tDCS.

Device: 1x1 Low Intensity Transcranial Direct Current Stimulation (tDCS)

Healthy Controls - Group 2b - Sham tDCS first

SHAM COMPARATOR

Half of the healthy controls will receive sham tDCS in the first session. Following cross-over and a three-week washout-period, this half of the healthy controls will receive active (anodal, real) tDCS.

Device: 1x1 Low Intensity Transcranial Direct Current Stimulation (tDCS)

Interventions

1x1 Low Intensity Transcranial Direct Current Stimulation (tDCS) DEVICE

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.

Healthy Controls - Group 2a - Active tDCS first; Healthy Controls - Group 2b - Sham tDCS first; Parkinson Disease - Group 1a - Active tDCS first; Parkinson Disease - Group 1b - Sham tDCS first

Eligibility Criteria

• Age: 55 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• diagnosed with the idiopathic form of PD by a neurologist (PD subjects only)
• Dutch or French speaking
• sufficient upper limb motor skills to perform the SRT-task (determined by means of a practice version of the SRT-task consisting of one block of 50 random trials)
• able to signal pain or discomfort
• able to give informed consent

You may not qualify if:

• additional neurological disorders
• any of the following tDCS contra-indications: deep brain stimulator; pacemaker; head wound; skin condition of the scalp; a history of epilepsy

Sponsors & Collaborators

• Vrije Universiteit Brussel: lead

Study Sites (1)

Vrije Universiteit Brussel

Brussels, Brussels Capital, 1050, Belgium

Location

MeSH Terms

Conditions

Parkinson Disease

Condition Hierarchy (Ancestors)

Parkinsonian Disorders; Basal Ganglia Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Movement Disorders; Synucleinopathies; Neurodegenerative Diseases

Study Officials

• Natacha Deroost, PhD

  Vrije Universiteit Brussel - Brain Body and Cognition Research Group

  STUDY DIRECTOR

• Kris Baetens, PhD

  Vrije Universiteit Brussel - Brain Body and Cognition Research Group

  STUDY CHAIR

• Chris Baeken, PhD, MD

  University Ghent

  STUDY CHAIR

• Frank Van Overwalle, PhD

  Vrije Universiteit Brussel - Brain Body and Cognition Research Group

  STUDY CHAIR

• Eva Swinnen, PhD

  Vrije Universiteit Brussel - Rehabilitation Research Group

  STUDY CHAIR

• Mahyar Firouzi, PhD

  Vrije Universiteit Brussel - Brain Body and Cognition Research Group

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, CARE PROVIDER
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principle Investigator (Doctoral Researcher)

Model Details: sham-controlled, counterbalanced study

Study Record Dates

• First Submitted: October 10, 2020
• First Posted: October 28, 2020
• Study Start: October 11, 2020
• Primary Completion: August 31, 2022
• Study Completion: August 31, 2022
• Last Updated: May 2, 2022

Record last verified: 2022-04

Locations

BE (1)