Date Presented 04/03/2025
This study examines the effect of high-definition transcranial direct current stimulation on upper extremity function in the chronic stroke population to aid in the development of individually tailored intervention plans for clients with varying degrees of motor impairment.
Primary Author and Speaker: Bethany Marshall
Contributing Authors: Joohwan Sung, Beni Endharto Mulyana, Mahmood Rajabtabar, Rita Huan-Ting Peng, Luka Bryant, Carly Skadden, Renee Daniels, Sanjiv Jain, Yuan Yang
PURPOSE: This study explores the use of high-definition transcranial direct current stimulation (HD-tDCS) to reduce motor deficits post-stroke. In theory, tDCS modulates the excitability of motor pathways associated with abnormal muscle tone and reduced AROM. Existing clinical works use tDCS with sponge electrodes which stimulate large areas of the brain, whereas HD-tDCS can precisely target specific brain regions.
DESIGN: A randomized, double-blind, sham-controlled cross-over study was conducted on chronic stroke survivors with Fugl-Meyer Upper-Extremity (FM-UE) scores between 8 and 48 during screening. All participants received one of four types of stimulation in a randomized order with a two-week washout period between sessions. Stimulation types were 1) cathodal HD-tDCS at the contralesional dorsal premotor cortex (cPMd), 2) anodal HD-tDCS at the ipsilesional primary motor cortex (iM1), 3) bilateral stimulation (cathodal cPMd and anodal iM1), or 4) sham stimulation.
METHOD: Pre and post session data was collected from 9 participants using the FM-UE and Modified Ashworth Scale (MAS) as outcome measures. Data was analyzed at the individual level due to small sample size.
RESULTS: Six out of nine participants with initial FM-UE scores between 22-37 had increases in FM-UE scores after at least one active HD-tDCS session as compared to sham stimulation, though the best stimulation type varied between participants. Among them, muscle tone was reduced in 4 participants as indicated by a decrease in MAS score(s).
CONCLUSION: Chronic stroke clients with moderate motor impairment may benefit from HD-tDCS to improve the use of their affected UE. Future research includes refining dosages for long-term reduction in impairment, exploring the use of HD-tDCS with (sub)acute stroke populations, and combining HD-tDCS with OT intervention. One day, OTPs may use HD-tDCS as a PAM to promote increased functional gains. This work is supported by American Heart Association (932980).
References
Peng, R. H., He, D., James, S. A., Williamson, J. N., Skadden, C., Jain, S., Hassaneen, W., Miranpuri, A., Kaur, A., Sarol, J. N., & Yang, Y. (2024). Determining the effects of targeted high-definition transcranial direct current stimulation on reducing post-stroke upper limb motor impairments-a randomized cross-over study. Trials, 25(1), 34. https://doi.org/10.1186/s13063-023-07886-w
Williamson, J. N., James, S. A., He, D., Li, S., Sidorov, E. V., & Yang, Y. (2023). High-definition transcranial direct current stimulation for upper extremity rehabilitation in moderate-to-severe ischemic stroke: a pilot study. Frontiers in Human Neuroscience, 17, 1286238. https://doi.org/10.3389/fnhum.2023.1286238
