The Effects of Cathodal tDCS on Muscle Strength in Healthy Adults

Healthy Participants Clinical Trial

Official title:

The Effects of Cathodal tDCS on Muscle Strength in Healthy Adults

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04672122
• Other study ID #: MU-CIRB2020/314.0210
• Status: Completed
• Phase: N/A
• Start date: November 16, 2020
• Est. completion date: March 31, 2022

Study information

• Verified date: June 2022
• Source: Mahidol University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

To investigate the effects of different intensity of cathodal tDCS on muscle strength in healthy adults.

Description:

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that can modulate cortical excitability. In 2000, Nitsche and Paulus reported the polarity-dependent effect of tDCS in humans, i.e., anodal tDCS facilitates cortical excitability while cathodal tDCS decreases it. (Nitsche & Paulus, 2000). TDCS studies have been replicated by many researchers and reported similar effects of tDCS in humans when using anodal and cathodal tDCS with an intensity of 1 mA. The linear effect of tDCS also has been reported by various studies, i.e., when increase intensity, the polarity-dependent effect of tDCS also enhances. However, conflicting results of cathodal tDCS efficacy have been reported.

Cortical excitability has been used to represent the efficacy of tDCS on neuroplasticity. The linear effect of cathodal tDCS on cortical excitability have been reported by researchers when using intensities at 1, 2, and 3 mA stimulated at the primary motor cortex in healthy participants (Batsikadze et al., 2013; Jamil et al., 2017; Kuo et al., 2013; Mosayebi Samani et al., 2019; Nitsche et al., 2003). Nevertheless, some studies showed the non-linear effects of cathodal tDCS (i.e., when increases intensity, cathodal tDCS enhances the cortical excitability) when using intensities at 1.5 and 2 mA in healthy participants (Batsikadze et al., 2013; Jamil et al., 2017; Mosayebi Samani et al., 2019). Hence, cathodal tDCS efficacy on cortical excitability is still controversy.

Muscle performance is an outcome that represents clinical change induced by tDCS. Previous studies reported the tendency of cathodal tDCS efficacy in decreasing muscle performance of both upper and lower extremities in healthy participants (Cogiamanian et al., 2007; Tanaka et al., 2009). However, previous studies used a single intensity of tDCS in each study. Hence, there was no direct comparison between different intensities of cathodal tDCS on muscle performance in healthy participants.

In our study, we aim to investigate the effect of different intensities of cathodal tDCS on muscle strength in healthy participants.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 48
• Est. completion date: March 31, 2022
• Est. primary completion date: March 31, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 60 Years

Eligibility

Inclusion Criteria:

1. Male and female healthy adults

2. Age range between 18 - 60 years old

3. Right-handed dominant identified by the Edinburg Handedness Inventory

4. No recent muscle injuries of both limbs for a past 6-months

Exclusion Criteria:

1. Consumed caffeine within 24 hours prior the experiment

2. History of neurological symptoms i.e. seizures, weakness, loss of sensation or unclear history of pass illness

3. Presence of metal implantation, intracranial shunt, cochlear implantation or cardiac pacemakers

4. Presence of opened wound or infectious wound around scalp

5. Presence of pain in evaluating muscle groups

6. History of surgery in evaluating limbs

Related Conditions & MeSH terms

• Healthy Participants

Intervention

Device:
• Transcranial direct current stimulation
Cathodal tDCS will be applied for 20 mins.

Locations

Country	Name	City	State
Thailand	Faculty of Physical Therapy, Mahidol University	Salaya	Nakhon Pathom

Sponsors (1)

Lead Sponsor	Collaborator
Mahidol University

Country where clinical trial is conducted

Thailand, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change from baseline muscle strength after tDCS	Muscle strength will be measured in Newton by using a hand-held dynamometer.	Baseline (Pretest) and 40 minutes ( posttest)