Effect of tACS on the Recovery of Motor Control of the Upper Limb and Cerebral Connectivity in Chronic Stroke Patients

NCT05947318 | Completed

• 1 other identifier: FONDECYT N° 11221226
• Study Type: interventional
• Target: 59
• Locations: 1 country
• Sites: 1

Brief Summary

This project seeks to evaluate the effect of transcranial alternating current stimulation (tACS) on the recovery of motor control of the upper limb and associated neuronal synchrony during a 14-sessions (5-week) rehabilitation program for adult patients with diagnosis of stroke at chronic stage. Specifically, the stimulation on Gamma ranges, because the evidence available so far allows us to propose that the tACS in the Gamma range (around 70 Hz) facilitates motor execution. For this purpose, the experimental approach involves active (70 Hz in Gamma rhythm and 7 Hz, Theta rhythm) and sham tACS together with an analytical and integrated motor training with a double-blind and randomized design. Our hypothesis is that Gamma frequency tACS restores neuronal synchrony in Beta range, which enhances the upper limb motor recovery associated with a training program. Using specific motor control parameters, clinical scales and electroencephalography, the immediate and long-term (3 months after finished the training) behavioral and neurophysiological effect of this new neurostimulation paradigm (tACS plus training) for motor rehabilitation of stroke will be established.

Conditions

Chronic Stroke; Rehabilitation

Keywords

transcranial alternating current stimulation; motor recovery; stroke rehabilitation

Outcome Measures

Primary Outcomes (6)

• Impairment Measure pre-intervention: Upper Extremity Fugl Meyer

  Scale use to assess motor impairments (ICF function level), and adequately reflects the analytical motor control of force and direction of movement. The scale has a maximum of 66 points, which indicates a normal performance. Lower scores indicate worse performance.

  week 0

• Change of Impairment Measure post-intervention: Upper Extremity Fugl Meyer

  Scale use to assess motor impairments (ICF function level), and adequately reflects the analytical motor control of force and direction of movement. The scale has a maximum of 66 points, which indicates a normal performance. Lower scores indicate worse performance.

  week 5 or 6 (end of the training program)

• Change of Impairment Measure follow up: Upper Extremity Fugl Meyer

  Scale use to assess motor impairments (ICF function level), and adequately reflects the analytical motor control of force and direction of movement. The scale has a maximum of 66 points, which indicates a normal performance. Lower scores indicate worse performance.

  week 12

• EEG spectral power in Beta band pre-intervention

  Change in spectral power in the Beta band (13-30Hz) associated with motor performance in kinetic and kinematic tasks

  week 0

• Change in EEG spectral power in Beta band post-intervention

  Change in spectral power in the Beta band (13-30Hz) associated with motor performance in kinetic and kinematic tasks

  week 5 or 6 (end of the training program)

• Change in EEG spectral power in Beta band follow up

  Change in spectral power in the Beta band (13-30Hz) associated with motor performance in kinetic and kinematic tasks

  week 12

Secondary Outcomes (9)

• Activity Measure: Action Research Arm Test

  week 0, week 5 or 6 (end of the training program) and week 12

• Change in Activity Measure post-intervention: Action Research Arm Test

  week 5 or 6 (end of the training program)

• Change in Activity Measure follow up: Action Research Arm Test

  week 12

• Performance measure in the trained kinetic task (behavioral parameter)

  week 0, week 5 or 6 (end of the training program) and week 12

• Change in the performance measure in the trained kinetic task post-intertenvion (behavioral parameter)

  week 5 or 6 (end of the training program)

Study Arms (3)

tACS - 70 Hz group

EXPERIMENTAL

The group will receive the training program plus 20 minutes of tACS at 70 Hz in the C3 or C4 electrode position (depending of the hemiparetic arm) during a specific kinetic and kinematic tasks in every training session.

Device: transcranial alternating current stimulation 70 Hz; Behavioral: Training

tACS - 7 Hz group

ACTIVE COMPARATOR

The group will receive the training program plus 20 minutes of tACS at 7 Hz in the C3 or C4 electrode position (depending of the hemiparetic arm) during a specific kinetic and kinematic tasks in every training session.

Behavioral: Training; Device: transcranial alternating current stimulation 7 Hz

tACS - sham group

SHAM COMPARATOR

The group will receive the training program plus 30 seconds of tACS at 70 Hz in the C3 or C4 electrode position (depending of the hemiparetic arm) in every training session.

Behavioral: Training; Device: transcranial alternating current stimulation Sham

Interventions

transcranial alternating current stimulation 70 Hz DEVICE

Transcranial alternating current stimulation in the head above the motor cortex area of one side of the brain, according to the hemiparesis side. Electrodes with 3.14 cm2 of stimulation area will be used, therefore, the initial current intensity will be 0.21 mA, with a current density of 0.07 mA / cm2. The current intensity will be adjusted to the tactile sensory threshold and phosphenes of each patient, with in order to reduce such sensory effects, but considering that the decrease in current will not be greater than 10% of the initial intensity, in order to obtain a comparable configuration between subjects. The frequency stimulation will be 70 Hz

tACS - 70 Hz group

Training BEHAVIORAL

Training of the upper limb with specific kinematic and kinetic tasks plus functional training

tACS - 7 Hz group; tACS - 70 Hz group; tACS - sham group

transcranial alternating current stimulation 7 Hz DEVICE

Transcranial alternating current stimulation in the head above the motor cortex area of one side of the brain, according to the hemiparesis side. Electrodes with 3.14 cm2 of stimulation area will be used, therefore, the initial current intensity will be 0.21 mA, with a current density of 0.07 mA / cm2. The current intensity will be adjusted to the tactile sensory threshold and phosphenes of each patient, with in order to reduce such sensory effects, but considering that the decrease in current will not be greater than 10% of the initial intensity, in order to obtain a comparable configuration between subjects. The frequency stimulation will be 7 Hz

tACS - 7 Hz group

transcranial alternating current stimulation Sham DEVICE

Transcranial alternating current stimulation in the head above the motor cortex area of one side of the brain, according to the hemiparesis side. Electrodes with 3.14 cm2 of stimulation area will be used, therefore, the initial current intensity will be 0.21 mA, with a current density of 0.07 mA / cm2. The current intensity will be adjusted to the tactile sensory threshold and phosphenes of each patient, with in order to reduce such sensory effects, but considering that the decrease in current will not be greater than 10% of the initial intensity, in order to obtain a comparable configuration between subjects. The stimulation will be turn on for 30 seconds (at 70 Hz)

tACS - sham group

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Diagnosis of unilateral stroke at chronic stage (6 months or more)
• Upper Extremity -Fugl Meyer \> 10
• Wrist extensors strength of the paretic limb of 2 or more in the Medical Research Council (MRC) scale
• Active shoulder movement (flexion or abduction) of 30º or more
• Be able to follow the instructions necessary to achieve the training protocol

You may not qualify if:

• Have a cerebellar stroke or ataxia
• Have some medical condition contraindicated for tACS (epilepsy, pacemaker, prosthesis between others)
• Have post-stroke epilepsy
• Limited passive range of motion in the elbow (less than 45º in flexo-extension plane)
• Limited passive range of motion in the wrist (less than 40º in flexo-extension plane)
• Limited passive range of motion in the shoulder (less than 70º in flexo-extension plane)
• Have another neurological condition that leads to upper extremity sequelae
• Have a normal performance in the clinical test

Sponsors & Collaborators

• Universidad Metropolitana de Ciencias de la Educacion: lead

Study Sites (1)

Centro de Habilidades Clínicas - Universidad Metropolitana de Ciencias de la Educación

Santiago, Santiago Metropolitan, 7780450, Chile

Location

Related Publications (1)

• Alisar DC, Ozen S, Sozay S. Effects of Bihemispheric Transcranial Direct Current Stimulation on Upper Extremity Function in Stroke Patients: A randomized Double-Blind Sham-Controlled Study. J Stroke Cerebrovasc Dis. 2020 Jan;29(1):104454. doi: 10.1016/j.jstrokecerebrovasdis.2019.104454. Epub 2019 Nov 4.

  PMID: 31699572 BACKGROUND

Study Officials

• Juan J Mariman, Ph.D

  Universidad Metropolitana de Ciencias de la Educacion

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, OUTCOMES ASSESSOR
• Masking Details: Neither the participant or the professionals that will make the training and the assessments will know to which group the participants was assigned.
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Full professor

Model Details: Three experimental groups: 1. tACS-70 Hz group 2. tACS-7Hz group 3. tACS-sham group

Study Record Dates

• First Submitted: June 12, 2023
• First Posted: July 17, 2023
• Study Start: May 2, 2023
• Primary Completion: April 7, 2025
• Study Completion: April 7, 2025
• Last Updated: April 29, 2025

Record last verified: 2025-04

Data Sharing

• IPD Sharing: Will not share

Locations

CL (1)