Resting-State Activity Changes Induced by tDCS in MS Patients and Healthy Controls: A Simultaneous tDCS rs-fMRI Study
Year: 2025
Type: article
Study design: Clinical Trial
Abstract: Transcranial direct current stimulation (tDCS) is a safe, well-tolerated method of non-invasively eliciting cortical neuromodulation. It has gained recent interest, especially for its positive clinical outcomes in neurodegenerative diseases such as multiple sclerosis (MS). However, its simultaneous (during tDCS) and cumulative effects (following repeated tDCS sessions) on the regional brain activity during rest need further investigation, especially in MS. This study aims to elucidate tDCS' underpinnings, alongside its therapeutic impact in MS patients, using concurrent tDCS-MRI methods. In total, 20 MS patients (age = 48 ± 12 years; 8 males) and 28 healthy controls (HCs; age = 36 ± 15 years; 12 males) were recruited. They participated in a tDCS-MRI session, during which resting-state functional MRI (rs-fMRI) was used to measure the levels of the fractional amplitude of low-frequency fluctuations (fALFFs), which is an index of regional neuronal activity, before and during left anodal dorsolateral prefrontal cortex (DLPFC) tDCS (2.0 mA for 15 min). MS patients were then asked to return for an identical tDCS-MRI visit (follow-up) after 20 identical at-home tDCS sessions. Simultaneous tDCS-induced changes in fALFF are seen across cortical and subcortical areas in both HC and MS patients, with some regions showing increased and others decreased brain activity. In HCs, fALFF increased in the right pre- and post-central gyrus whilst it decreased in subcortical regions. Conversely, MS patients initially displayed increases in more posterior cortical regions but decreases in the superior and temporal cortical regions. At follow-up, MS patients showed reversed patterns, emphasizing significant cumulative effects of tDCS treatment upon brain excitation. Such long-lasting changes are further supported by greater pre-tDCS fALFFs measured at follow-up compared to baseline, especially around the cuneus. The results were significant after correcting for multiple comparisons (p-FDR < 0.05). Our study shows that tDCS has both simultaneous and cumulative effects on neuronal activity measured with rs-fMRI, especially involving major brain areas distant from the site of stimulation, and it is responsible for fatigue and cognitive and motor skills.
Source: Bioengineering
Language: English
Subfield: Neurology
Field: Neuroscience
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,258
Awards: A PILOT TRIAL OF REMOTELY SUPERVISED TRANSCRANIAL DIRECT CURRENT STIMULATION (RS-TDCS) TO ENHANCE MOTOR LEARNING IN PROGRESSIVE MULTIPLE SCLEROSIS (M, kHz frequency Spinal Cord Stimulation: Novel Temperature-Based Mechanisms of Action, G2040153736, G2728840789, "Bridges to the Baccalaureate Research Training Program at LaGuardia Community College", Non-Invasive Vagal Nerve Stimulation in Patients with Opioid Use Disorders, G3058810741, G3088859791, G3904296419, G4119534169, G5162087599, G5850682332, G6344043434, G6418790712, G697162804, G7383942181, G7459171603, AN EASILY IMPLEMENTED WEARABLE REMOTE DATA CAPTURE SOLUTION FOR HOME-BASED GAIT ASSESSMENT IN MULTIPLE SCLEROSIS, Effects of direct-current stimulation on synaptic plasticity, G8420876188, G9000006972, G9000064632, G9000083130, G9000171398
OpenAlex ID: W4411456255