NCT05503823

Investigating Transcranial Alternating Current Stimulation (tACS) Preconditioning Effects on Resting and Active Motor Threshold

Terminated NA Results posted Last updated 6 October 2023

What this trial tests

NA trial testing tACS or tRNS and TMS in Understand the Effects of tACS on the Brain in 6 participants. Terminated before completion.

Timeline

16 September 2022

Primary endpoint
1 July 2023

1 July 2023

Quick facts

Lead sponsor	University of Manitoba
Phase	NA
Status	Terminated
Study type	INTERVENTIONAL
Allocation	na
Design	single group
Masking	none
Primary purpose	basic science
Enrollment	6
Start date	16 September 2022
Primary completion	1 July 2023
Estimated completion	1 July 2023
Sites	1 location across Canada

Drugs / interventions tested

• tACS or tRNS and TMS

Conditions studied

• Understand the Effects of tACS on the Brain — all drugs for Understand the Effects of tACS on the Brain →

Sponsor

University of Manitoba

Who can join

Adults 18 to 95, any sex, with Understand the Effects of tACS on the Brain. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Resting Motor Threshold Primary · Before tACS, right after tACS, 30 minutes after tACS, and 1 hour after tACS

The peak-to-peak amplitude of the muscle signal from the resting motor threshold.

Before

Group	Value	95% CI
Resting Motor Threshold With tACS	76.5	± 26.6

After

Group	Value	95% CI
Resting Motor Threshold With tACS	108.7	± 43.2

30 min After

Group	Value	95% CI
Resting Motor Threshold With tACS	130.1	± 45

1 hour After

Group	Value	95% CI
Resting Motor Threshold With tACS	85.8	± 25.1

Active Motor Threshold Secondary · Before tACS, right after tACS, 30 minutes after tACS, and 1 hour after tACS

Cortical silent period measured post-MEP.

Before

Group	Value	95% CI
Active Motor Threshold With tACS	131.1

After

Group	Value	95% CI
Active Motor Threshold With tACS	123.1

30 min After

Group	Value	95% CI
Active Motor Threshold With tACS	81.4

1 hour After

Group	Value	95% CI
Active Motor Threshold With tACS	108.75

Sponsor's own description

Previous studies have looked at the potential of using transcranial direct current stimulation (tDCS) to prime the brain in order to lower the resting motor threshold. The resting motor threshold (RMT) is the intensity at which repeated transcranial magnetic stimulation (rTMS) is applied for treatments. The RMT is the lowest intensity at which the participant's muscle responds with the motor evoked potential peak-to-peak amplitude greater than 50μV for 5 of 10 trials when the hand is relaxed. The active motor threshold (AMT) is the lowest intensity that produces MEP with peak-to-peak amplitude greater than 100 μV for 5 of 10 trials while the participant maintains 10-30% of maximal voluntary contraction. The RMT and AMT is different for each person and the high intensity TMS pulses can be difficult for some of the patients in the current Alzheimer's rTMS treatment study to tolerate. Therefore, if the treatment can still be applied with lower intensities, it would be more tolerable for some people. The limited research on both tDCS and transcranial alternating current stimulation (tACS) in priming the brain for TMS are not enough to determine if they are effective in priming the brain. The studies that include tDCS have small sample size and inconclusive results. The studies with tACS are using very high frequencies of 140 Hz to 250 Hz. The objective of this research study is to determine if priming the brain with tACS at 40 Hz or tRNS for 10 minutes is able to reduce the resting and active motor threshold. Therefore, for people with higher RMT and AMT, priming with tACS or tRNS could be used to lower intensities while stimulating the brain for treatments.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.