Immediate Effects of Transcutaneous Spinal Cord Stimulation on Motor Function in Chronic, Sensorimotor Incomplete Spinal Cord Injury
Deficient ankle control after incomplete spinal cord injury (iSCI) often accentuates walking impairments. Transcutaneous electrical spinal cord stimulation (tSCS) has been shown to augment locomotor activity after iSCI, presumably due to modulation of spinal excitability. However, the effects of pos...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-11-01
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| Series: | Journal of Clinical Medicine |
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| Online Access: | https://www.mdpi.com/2077-0383/9/11/3541 |
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| author | Christian Meyer Ursula S. Hofstoetter Michèle Hubli Roushanak H. Hassani Carmen Rinaldo Armin Curt Marc Bolliger |
| author_facet | Christian Meyer Ursula S. Hofstoetter Michèle Hubli Roushanak H. Hassani Carmen Rinaldo Armin Curt Marc Bolliger |
| author_sort | Christian Meyer |
| collection | DOAJ |
| description | Deficient ankle control after incomplete spinal cord injury (iSCI) often accentuates walking impairments. Transcutaneous electrical spinal cord stimulation (tSCS) has been shown to augment locomotor activity after iSCI, presumably due to modulation of spinal excitability. However, the effects of possible excitability modulations induced by tSCS on ankle control have not yet been assessed. This study investigated the immediate (i.e., without training) effects during single-sessions of tonic tSCS on ankle control, spinal excitability, and locomotion in ten individuals with chronic, sensorimotor iSCI (American Spinal Injury Association Impairment Scale D). Participants performed rhythmic ankle movements (dorsi- and plantar flexion) at a given rate, and irregular ankle movements following a predetermined trajectory with and without tonic tSCS at 15 Hz, 30 Hz, and 50 Hz. In a subgroup of eight participants, the effects of tSCS on assisted over-ground walking were studied. Furthermore, the activity of a polysynaptic spinal reflex, associated with spinal locomotor networks, was investigated to study the effect of the stimulation on the dedicated spinal circuitry associated with locomotor function. Tonic tSCS at 30 Hz immediately improved maximum dorsiflexion by +4.6° ± 0.9° in the more affected lower limb during the rhythmic ankle movement task, resulting in an increase of +2.9° ± 0.9° in active range of motion. Coordination of ankle movements, assessed by the ability to perform rhythmic ankle movements at a given target rate and to perform irregular movements according to a trajectory, was unchanged during stimulation. tSCS at 30 Hz modulated spinal reflex activity, reflected by a significant suppression of pathological activity specific to SCI in the assessed polysynaptic spinal reflex. During walking, there was no statistical group effect of tSCS. In the subgroup of eight assessed participants, the three with the lowest as well as the one with the highest walking function scores showed positive stimulation effects, including increased maximum walking speed, or more continuous and faster stepping at a self-selected speed. Future studies need to investigate if multiple applications and individual optimization of the stimulation parameters can increase the effects of tSCS, and if the technique can improve the outcome of locomotor rehabilitation after iSCI. |
| first_indexed | 2024-03-10T15:07:44Z |
| format | Article |
| id | doaj.art-1ddfea87025347aeb36809d3c3ad445b |
| institution | Directory Open Access Journal |
| issn | 2077-0383 |
| language | English |
| last_indexed | 2024-03-10T15:07:44Z |
| publishDate | 2020-11-01 |
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| spelling | doaj.art-1ddfea87025347aeb36809d3c3ad445b2023-11-20T19:34:23ZengMDPI AGJournal of Clinical Medicine2077-03832020-11-01911354110.3390/jcm9113541Immediate Effects of Transcutaneous Spinal Cord Stimulation on Motor Function in Chronic, Sensorimotor Incomplete Spinal Cord InjuryChristian Meyer0Ursula S. Hofstoetter1Michèle Hubli2Roushanak H. Hassani3Carmen Rinaldo4Armin Curt5Marc Bolliger6Spinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, SwitzerlandCenter for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, AustriaSpinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, SwitzerlandSpinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, SwitzerlandSpinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, SwitzerlandSpinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, SwitzerlandSpinal Cord Injury Center, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, SwitzerlandDeficient ankle control after incomplete spinal cord injury (iSCI) often accentuates walking impairments. Transcutaneous electrical spinal cord stimulation (tSCS) has been shown to augment locomotor activity after iSCI, presumably due to modulation of spinal excitability. However, the effects of possible excitability modulations induced by tSCS on ankle control have not yet been assessed. This study investigated the immediate (i.e., without training) effects during single-sessions of tonic tSCS on ankle control, spinal excitability, and locomotion in ten individuals with chronic, sensorimotor iSCI (American Spinal Injury Association Impairment Scale D). Participants performed rhythmic ankle movements (dorsi- and plantar flexion) at a given rate, and irregular ankle movements following a predetermined trajectory with and without tonic tSCS at 15 Hz, 30 Hz, and 50 Hz. In a subgroup of eight participants, the effects of tSCS on assisted over-ground walking were studied. Furthermore, the activity of a polysynaptic spinal reflex, associated with spinal locomotor networks, was investigated to study the effect of the stimulation on the dedicated spinal circuitry associated with locomotor function. Tonic tSCS at 30 Hz immediately improved maximum dorsiflexion by +4.6° ± 0.9° in the more affected lower limb during the rhythmic ankle movement task, resulting in an increase of +2.9° ± 0.9° in active range of motion. Coordination of ankle movements, assessed by the ability to perform rhythmic ankle movements at a given target rate and to perform irregular movements according to a trajectory, was unchanged during stimulation. tSCS at 30 Hz modulated spinal reflex activity, reflected by a significant suppression of pathological activity specific to SCI in the assessed polysynaptic spinal reflex. During walking, there was no statistical group effect of tSCS. In the subgroup of eight assessed participants, the three with the lowest as well as the one with the highest walking function scores showed positive stimulation effects, including increased maximum walking speed, or more continuous and faster stepping at a self-selected speed. Future studies need to investigate if multiple applications and individual optimization of the stimulation parameters can increase the effects of tSCS, and if the technique can improve the outcome of locomotor rehabilitation after iSCI.https://www.mdpi.com/2077-0383/9/11/3541humannon-invasivespinal cord injuryspinal cord stimulationspinal reflexesvoluntary ankle control |
| spellingShingle | Christian Meyer Ursula S. Hofstoetter Michèle Hubli Roushanak H. Hassani Carmen Rinaldo Armin Curt Marc Bolliger Immediate Effects of Transcutaneous Spinal Cord Stimulation on Motor Function in Chronic, Sensorimotor Incomplete Spinal Cord Injury Journal of Clinical Medicine human non-invasive spinal cord injury spinal cord stimulation spinal reflexes voluntary ankle control |
| title | Immediate Effects of Transcutaneous Spinal Cord Stimulation on Motor Function in Chronic, Sensorimotor Incomplete Spinal Cord Injury |
| title_full | Immediate Effects of Transcutaneous Spinal Cord Stimulation on Motor Function in Chronic, Sensorimotor Incomplete Spinal Cord Injury |
| title_fullStr | Immediate Effects of Transcutaneous Spinal Cord Stimulation on Motor Function in Chronic, Sensorimotor Incomplete Spinal Cord Injury |
| title_full_unstemmed | Immediate Effects of Transcutaneous Spinal Cord Stimulation on Motor Function in Chronic, Sensorimotor Incomplete Spinal Cord Injury |
| title_short | Immediate Effects of Transcutaneous Spinal Cord Stimulation on Motor Function in Chronic, Sensorimotor Incomplete Spinal Cord Injury |
| title_sort | immediate effects of transcutaneous spinal cord stimulation on motor function in chronic sensorimotor incomplete spinal cord injury |
| topic | human non-invasive spinal cord injury spinal cord stimulation spinal reflexes voluntary ankle control |
| url | https://www.mdpi.com/2077-0383/9/11/3541 |
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