Transcutaneous spinal stimulation in people with and without spinal cord injury: Effect of electrode placement and trains of stimulation on threshold intensity
Abstract Transcutaneous spinal cord stimulation (TSS) is purported to improve motor function in people after spinal cord injury (SCI). However, several methodology aspects are yet to be explored. We investigated whether stimulation configuration affected the intensity needed to elicit spinally evoke...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-06-01
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| Series: | Physiological Reports |
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| Online Access: | https://doi.org/10.14814/phy2.15692 |
| _version_ | 1797397177490735104 |
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| author | Harrison T. Finn Elizabeth A. Bye Thomas G. Elphick Claire L. Boswell‐Ruys Simon C. Gandevia Jane E. Butler Martin E. Héroux |
| author_facet | Harrison T. Finn Elizabeth A. Bye Thomas G. Elphick Claire L. Boswell‐Ruys Simon C. Gandevia Jane E. Butler Martin E. Héroux |
| author_sort | Harrison T. Finn |
| collection | DOAJ |
| description | Abstract Transcutaneous spinal cord stimulation (TSS) is purported to improve motor function in people after spinal cord injury (SCI). However, several methodology aspects are yet to be explored. We investigated whether stimulation configuration affected the intensity needed to elicit spinally evoked motor responses (sEMR) in four lower limb muscles bilaterally. Also, since stimulation intensity for therapeutic TSS (i.e., trains of stimulation, typically delivered at 15–50 Hz) is sometimes based on the single‐pulse threshold intensity, we compared these two stimulation types. In non‐SCI participants (n = 9) and participants with a SCI (n = 9), three different electrode configurations (cathode–anode); L1‐midline (below the umbilicus), T11‐midline and L1‐ASIS (anterior superior iliac spine; non‐SCI only) were compared for the sEMR threshold intensity using single pulses or trains of stimulation which were recorded in the vastus medialis, medial hamstring, tibialis anterior, medial gastrocnemius muscles. In non‐SCI participants, the L1‐midline configuration showed lower sEMR thresholds compared to T11‐midline (p = 0.002) and L1‐ASIS (p < 0.001). There was no difference between T11‐midline and L1‐midline for participants with SCI (p = 0.245). Spinally evoked motor response thresholds were ~13% lower during trains of stimulation compared to single pulses in non‐SCI participants (p < 0.001), but not in participants with SCI (p = 0.101). With trains of stimulation, threshold intensities were slightly lower and the incidence of sEMR was considerably lower. Overall, stimulation threshold intensities were generally lower with the L1‐midline electrode configuration and is therefore preferred. While single‐pulse threshold intensities may overestimate threshold intensities for therapeutic TSS, tolerance to trains of stimulation will be the limiting factor in most cases. |
| first_indexed | 2024-03-09T01:06:12Z |
| format | Article |
| id | doaj.art-f2fdfbbc8056442b824b7382dcc4048b |
| institution | Directory Open Access Journal |
| issn | 2051-817X |
| language | English |
| last_indexed | 2024-03-09T01:06:12Z |
| publishDate | 2023-06-01 |
| publisher | Wiley |
| record_format | Article |
| series | Physiological Reports |
| spelling | doaj.art-f2fdfbbc8056442b824b7382dcc4048b2023-12-11T09:37:12ZengWileyPhysiological Reports2051-817X2023-06-011111n/an/a10.14814/phy2.15692Transcutaneous spinal stimulation in people with and without spinal cord injury: Effect of electrode placement and trains of stimulation on threshold intensityHarrison T. Finn0Elizabeth A. Bye1Thomas G. Elphick2Claire L. Boswell‐Ruys3Simon C. Gandevia4Jane E. Butler5Martin E. Héroux6Neuroscience Research Australia Randwick New South Wales AustraliaNeuroscience Research Australia Randwick New South Wales AustraliaNeuroscience Research Australia Randwick New South Wales AustraliaNeuroscience Research Australia Randwick New South Wales AustraliaNeuroscience Research Australia Randwick New South Wales AustraliaNeuroscience Research Australia Randwick New South Wales AustraliaNeuroscience Research Australia Randwick New South Wales AustraliaAbstract Transcutaneous spinal cord stimulation (TSS) is purported to improve motor function in people after spinal cord injury (SCI). However, several methodology aspects are yet to be explored. We investigated whether stimulation configuration affected the intensity needed to elicit spinally evoked motor responses (sEMR) in four lower limb muscles bilaterally. Also, since stimulation intensity for therapeutic TSS (i.e., trains of stimulation, typically delivered at 15–50 Hz) is sometimes based on the single‐pulse threshold intensity, we compared these two stimulation types. In non‐SCI participants (n = 9) and participants with a SCI (n = 9), three different electrode configurations (cathode–anode); L1‐midline (below the umbilicus), T11‐midline and L1‐ASIS (anterior superior iliac spine; non‐SCI only) were compared for the sEMR threshold intensity using single pulses or trains of stimulation which were recorded in the vastus medialis, medial hamstring, tibialis anterior, medial gastrocnemius muscles. In non‐SCI participants, the L1‐midline configuration showed lower sEMR thresholds compared to T11‐midline (p = 0.002) and L1‐ASIS (p < 0.001). There was no difference between T11‐midline and L1‐midline for participants with SCI (p = 0.245). Spinally evoked motor response thresholds were ~13% lower during trains of stimulation compared to single pulses in non‐SCI participants (p < 0.001), but not in participants with SCI (p = 0.101). With trains of stimulation, threshold intensities were slightly lower and the incidence of sEMR was considerably lower. Overall, stimulation threshold intensities were generally lower with the L1‐midline electrode configuration and is therefore preferred. While single‐pulse threshold intensities may overestimate threshold intensities for therapeutic TSS, tolerance to trains of stimulation will be the limiting factor in most cases.https://doi.org/10.14814/phy2.15692spinal cord injurytranscutaneous spinal stimulation |
| spellingShingle | Harrison T. Finn Elizabeth A. Bye Thomas G. Elphick Claire L. Boswell‐Ruys Simon C. Gandevia Jane E. Butler Martin E. Héroux Transcutaneous spinal stimulation in people with and without spinal cord injury: Effect of electrode placement and trains of stimulation on threshold intensity Physiological Reports spinal cord injury transcutaneous spinal stimulation |
| title | Transcutaneous spinal stimulation in people with and without spinal cord injury: Effect of electrode placement and trains of stimulation on threshold intensity |
| title_full | Transcutaneous spinal stimulation in people with and without spinal cord injury: Effect of electrode placement and trains of stimulation on threshold intensity |
| title_fullStr | Transcutaneous spinal stimulation in people with and without spinal cord injury: Effect of electrode placement and trains of stimulation on threshold intensity |
| title_full_unstemmed | Transcutaneous spinal stimulation in people with and without spinal cord injury: Effect of electrode placement and trains of stimulation on threshold intensity |
| title_short | Transcutaneous spinal stimulation in people with and without spinal cord injury: Effect of electrode placement and trains of stimulation on threshold intensity |
| title_sort | transcutaneous spinal stimulation in people with and without spinal cord injury effect of electrode placement and trains of stimulation on threshold intensity |
| topic | spinal cord injury transcutaneous spinal stimulation |
| url | https://doi.org/10.14814/phy2.15692 |
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