Clinical trial NCT05576129: Transcranial Alternating Current Stimulation (tACS) to Improve Motor Skill Acquisition in Stroke Patients
Official title: Theta-gamma Transcranial Alternating Current Stimulation (tACS) to Modulate Activity in Sensorimotor Cortex for Improvement of Motor Skill Acquisition in Stroke Patients
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Stroke
Keywords: Stroke
Hand motor impairment
Transcranial alternating current stimulation
Non-invasive brain stimulation
motor learning
sensorimotor cortex
crossfrequency coupling
theta-gamma phase amplitude coupling
Lead sponsor: Universitätsklinikum Hamburg-Eppendorf
Sponsor class: OTHER
Collaborators: name: Technical University of Twente
name: University of Oxford
First posted: 2022-10-12
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: Hand motor function is often severely affected in stroke patients and its recovery is one primary goal in stroke rehabilitative treatment programs. Recently, theta-gamma transcranial alternating current stimulation (tACS) has been shown to enhance motor skill acquisition in healthy individuals. The aim of the present study is to examine the effect of theta-gamma tACS on motor skill acquisition in chronic stroke patients.

Detailed description: Hand motor function is often severely affected in stroke patients and recovery of function is a primary goal in stroke rehabilitative treatment programs. Recently, theta-gamma tACS has been shown to enhance motor skill acquisition in healthy individuals \[Akkad et al.2021\]. The aim of the present study is to examine the effect of theta-gamma tACS on motor skill acquisition in chronic stroke patients.

In a randomized, controlled, triple-blind trial, chronic stroke patients with an initially impaired hand motor function will receive either (i) theta-gamma peak stimulation (TGP) or (ii) sham stimulation. TGP stimulation significantly improved motor learning in the study by Akkad et al (2021) compared to sham stimulation. tACS will be delivered through a five-electrode montage centered over the sensorimotor cortex on the lesioned side of the brain for approximately 38 min. During stimulation patients will perform a motor skill acquisition task performed with the affected hand. The task consists of short repetitive trials in which participants alternately press two buttons with their thumb. It is designed in a way that participants can improve their performance, more precisely the speed of button presses, and are encouraged to do so. To reduce skin sensations beneath the stimulation electrodes and thereby improve blinding compared to sham stimulation, a local anesthetic consisting of lidocaine and prilocaine will be administered underneath the stimulation electrodes.

Based on the results of the study by Akkad et al. (2021) and on the assumption that theta-gamma phase amplitude coupling is a key mechanism for motor skill acquisition, the investigators hypothesize that motor skill acquisition will differ significantly between the TGP and sham group.

Eligibility criteria: Inclusion Criteria:

* German-speaking
* ability to perform a thumb movement task with the affected hand
* first-ever clinical ischemic stroke in the chronic phase
* persistent mild motor deficit of the upper extremity or motor deficit of the upper extremity in the acute phase over \>24h

Exclusion Criteria:

* pronounced cognitive deficits
* history of major neurological or psychiatric illness other than stroke
* epilepsy or epileptic seizure in the history
* any devices or implants in the head region (e.g. cochlear implant, aneurysm clips),
* implanted pacemaker or medical pumps
* intake of psychotropic medication
* allergy to any ingredient of the local anesthetic cream
* pregnancy

Primary outcomes:
measure: Motor Skill Acquisition
timeFrame: Over the course of the motor task with a duration of 38 minutes and 20 seconds.
Secondary outcomes:
measure: Duration of Button Presses
timeFrame: Baseline (consisting of 20 trials) and each of 6 blocks (consisting of 40 trials each)
Other outcomes:
measure: "Thumb Speed" and "Thumb Acceleration"
timeFrame: Over the course of the motor task with a duration of 38 minutes and 20 seconds.
Locations:
city: Hamburg
country: Germany
facility: Department of Neurology, University Medical Center Hamburg-Eppendorf
Study officials:
affiliation: Department of Neurology; University Medical Center Hamburg-Eppendorf
name: Fanny Quandt, Dr.
role: PRINCIPAL_INVESTIGATOR
affiliation: Biomedical Signals and Systems, Technical Medical Centre, University of Twente, The Netherlands
name: Bettina Schwab, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Akkad H, Dupont-Hadwen J, Kane E, Evans C, Barrett L, Frese A, Tetkovic I, Bestmann S, Stagg CJ. Increasing human motor skill acquisition by driving theta-gamma coupling. Elife. 2021 Nov 23;10:e67355. doi: 10.7554/eLife.67355.
citation: Grigutsch LS, Haverland B, Timmsen LS, Asmussen L, Braass H, Wolf S, Luu TV, Stagg CJ, Schulz R, Quandt F, Schwab BC. Differential effects of theta-gamma tACS on motor skill acquisition in young individuals and stroke survivors: A double-blind, randomized, sham-controlled study. Brain Stimul. 2024 Sep-Oct;17(5):1076-1085. doi: 10.1016/j.brs.2024.09.001. Epub 2024 Sep 6.