Investigating Neurometabolite Changes in Response to Median Nerve Stimulation
ABSTRACT Background Rhythmic median nerve stimulation (MNS) at 10 Hz has been shown to cause a substantial reduction in tic frequency in individuals with Tourette syndrome. The mechanism of action is currently unknown but is hypothesized to involve entrainment of oscillations within the sensorimotor...
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Wiley
2025-01-01
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| Series: | Brain and Behavior |
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| Online Access: | https://doi.org/10.1002/brb3.70250 |
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| author | Mairi S. Houlgreave Katherine Dyke Adam Berrington Stephen R. Jackson |
| author_facet | Mairi S. Houlgreave Katherine Dyke Adam Berrington Stephen R. Jackson |
| author_sort | Mairi S. Houlgreave |
| collection | DOAJ |
| description | ABSTRACT Background Rhythmic median nerve stimulation (MNS) at 10 Hz has been shown to cause a substantial reduction in tic frequency in individuals with Tourette syndrome. The mechanism of action is currently unknown but is hypothesized to involve entrainment of oscillations within the sensorimotor cortex. Objective We used functional magnetic resonance spectroscopy (fMRS) to explore the dynamic effects of MNS on neurometabolite concentrations. Methods Here, we investigated the effects of rhythmic and arrhythmic 10 Hz MNS on glutamate (Glu) and GABA concentrations in the contralateral sensorimotor cortex in 15 healthy controls, using a blocked fMRS design. We used a Mescher–Garwood‐semi‐localized by adiabatic selective refocusing (MEGA‐sLASER) sequence at 7 T. Results Our results show no difference in the difference‐from‐baseline measures between the two stimulation conditions. Looking at the effect of MNS over both conditions there is a trend for an initial increase in Glu/tCr (total creatine) followed by a decrease over time, whereas GABA/tCr decreased during each stimulation block. Conclusions These results suggest that despite entrainment of oscillations during rhythmic MNS, there are no significant differences in the tonic neuromodulatory effects of rhythmic and arrhythmic stimulation. The reduction in Glu over the course of stimulation may reflect a decrease in the glutamatergic firing due to adaptation. This may make it less likely that an involuntary movement is generated during continuous stimulation. |
| format | Article |
| id | doaj-art-88b5ddee38244f05999358e7ae0c8f22 |
| institution | Kabale University |
| issn | 2162-3279 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Wiley |
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| series | Brain and Behavior |
| spelling | doaj-art-88b5ddee38244f05999358e7ae0c8f222025-01-29T13:36:39ZengWileyBrain and Behavior2162-32792025-01-01151n/an/a10.1002/brb3.70250Investigating Neurometabolite Changes in Response to Median Nerve StimulationMairi S. Houlgreave0Katherine Dyke1Adam Berrington2Stephen R. Jackson3School of Psychology University of Nottingham University Park Nottingham UKSchool of Psychology University of Nottingham University Park Nottingham UKSir Peter Mansfield Imaging Centre, School of Physics and Astronomy University of Nottingham University Park Nottingham UKSchool of Psychology University of Nottingham University Park Nottingham UKABSTRACT Background Rhythmic median nerve stimulation (MNS) at 10 Hz has been shown to cause a substantial reduction in tic frequency in individuals with Tourette syndrome. The mechanism of action is currently unknown but is hypothesized to involve entrainment of oscillations within the sensorimotor cortex. Objective We used functional magnetic resonance spectroscopy (fMRS) to explore the dynamic effects of MNS on neurometabolite concentrations. Methods Here, we investigated the effects of rhythmic and arrhythmic 10 Hz MNS on glutamate (Glu) and GABA concentrations in the contralateral sensorimotor cortex in 15 healthy controls, using a blocked fMRS design. We used a Mescher–Garwood‐semi‐localized by adiabatic selective refocusing (MEGA‐sLASER) sequence at 7 T. Results Our results show no difference in the difference‐from‐baseline measures between the two stimulation conditions. Looking at the effect of MNS over both conditions there is a trend for an initial increase in Glu/tCr (total creatine) followed by a decrease over time, whereas GABA/tCr decreased during each stimulation block. Conclusions These results suggest that despite entrainment of oscillations during rhythmic MNS, there are no significant differences in the tonic neuromodulatory effects of rhythmic and arrhythmic stimulation. The reduction in Glu over the course of stimulation may reflect a decrease in the glutamatergic firing due to adaptation. This may make it less likely that an involuntary movement is generated during continuous stimulation.https://doi.org/10.1002/brb3.70250GABAglutamatemagnetic resonance spectroscopymedian nerve stimulationsensorimotor cortex |
| spellingShingle | Mairi S. Houlgreave Katherine Dyke Adam Berrington Stephen R. Jackson Investigating Neurometabolite Changes in Response to Median Nerve Stimulation Brain and Behavior GABA glutamate magnetic resonance spectroscopy median nerve stimulation sensorimotor cortex |
| title | Investigating Neurometabolite Changes in Response to Median Nerve Stimulation |
| title_full | Investigating Neurometabolite Changes in Response to Median Nerve Stimulation |
| title_fullStr | Investigating Neurometabolite Changes in Response to Median Nerve Stimulation |
| title_full_unstemmed | Investigating Neurometabolite Changes in Response to Median Nerve Stimulation |
| title_short | Investigating Neurometabolite Changes in Response to Median Nerve Stimulation |
| title_sort | investigating neurometabolite changes in response to median nerve stimulation |
| topic | GABA glutamate magnetic resonance spectroscopy median nerve stimulation sensorimotor cortex |
| url | https://doi.org/10.1002/brb3.70250 |
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