Journal article
Simultaneous Recording of Motor Evoked Potentials in Hand, Wrist and Arm Muscles to Assess Corticospinal Divergence
Brain topography, Vol.34(4), pp.415-429
07/2021
DOI: 10.1007/s10548-021-00845-1
PMCID: PMC8858648
PMID: 33945041
Abstract
The purpose of this study was to further develop methods to assess corticospinal divergence and muscle coupling using transcranial magnetic stimulation (TMS). Ten healthy right-handed adults participated (7 females, age 34.0 ± 12.9 years). Monophasic single pulses were delivered to 14 sites over the right primary motor cortex at 40, 60, 80 and 100% of maximum stimulator output (MSO), using MRI-based neuronavigation. Motor evoked potentials (MEPs) were recorded simultaneously from 9 muscles of the contralateral hand, wrist and arm. For each intensity, corticospinal divergence was quantified by the average number of muscles that responded to TMS per cortical site, coactivation across muscle pairs as reflected by overlap of cortical representations, and correlation of MEP amplitudes across muscle pairs. TMS to each muscle's most responsive site elicited submaximal MEPs in most other muscles. The number of responsive muscles per cortical site and the extent of coactivation increased with increasing intensity (ANOVA, p < 0.001). In contrast, correlations of MEP amplitudes did not differ across the 60, 80 and 100% MSO intensities (ANOVA, p = 0.34), but did differ across muscle pairs (ANOVA, p < 0.001). Post hoc analysis identified 4 sets of muscle pairs (Tukey homogenous subsets, p < 0.05). Correlations were highest for pairs involving two hand muscles and lowest for pairs that included an upper arm muscle. Correlation of MEP amplitudes may quantify varying levels of muscle coupling. In future studies, this approach may be a biomarker to reveal altered coupling induced by neural injury, neural repair and/or motor learning.
Details
- Title: Subtitle
- Simultaneous Recording of Motor Evoked Potentials in Hand, Wrist and Arm Muscles to Assess Corticospinal Divergence
- Creators
- Stacey L DeJong - Roy J. and Lucille A. Carver College of MedicineJayden A Bisson - Roy J. and Lucille A. Carver College of MedicineWarren G Darling - University of IowaRichard K Shields - Roy J. and Lucille A. Carver College of Medicine
- Resource Type
- Journal article
- Publication Details
- Brain topography, Vol.34(4), pp.415-429
- DOI
- 10.1007/s10548-021-00845-1
- PMID
- 33945041
- PMCID
- PMC8858648
- NLM abbreviation
- Brain Topogr
- ISSN
- 0896-0267
- eISSN
- 1573-6792
- Grant note
- K12 HD055931 / NICHD NIH HHS S10 OD025025 / NIH HHS
- Language
- English
- Date published
- 07/2021
- Academic Unit
- Orthopedics and Rehabilitation; Physical Therapy and Rehabilitation Science; Health, Sport, and Human Physiology
- Record Identifier
- 9984259641802771
Metrics
10 Record Views