OBJECTIVES: Muscle vibration (MV) to a forearm muscle augments motor-evoked potentials (MEPs) following transcranial magnetic stimulation (TMS) and the underlying mechanism involves cortical structures. Although MV-induced cortical activation is bilateral, the effects of MV on MEPs in contralateral muscles have not been investigated. METHODS: Low-amplitude MV (80 Hz, amplitude 0.5 mm, duration 4 s), subthreshold for the tonic vibration reflex, was applied to the right extensor carpi radialis muscle (ECR). MEPs were elicited (0.5, 3 and 5 s after MV onset) in the left and right ECR and flexor carpi radialis muscle (FCR) by TMS (120% of threshold at rest) to the left and right hemisphere, respectively. RESULTS: During MV of right ECR the left ECR revealed a slight non-significant augmentation of MEPs. In contrast, the left FCR showed a gradual depression of MEPs with ongoing MV and at 3 s the reduction of MEPs was significant. The time course of MEP changes in left FCR correlated with the facilitation of the vibrated right ECR. Post-vibration MEPs at 1 s after the offset of MV were still significantly decreased. CONCLUSIONS: The study demonstrates crossed effects of MV on motor cortex excitability, suggesting transcallosal MEP modulation.
OBJECTIVES: Muscle vibration (MV) to a forearm muscle augments motor-evoked potentials (MEPs) following transcranial magnetic stimulation (TMS) and the underlying mechanism involves cortical structures. Although MV-induced cortical activation is bilateral, the effects of MV on MEPs in contralateral muscles have not been investigated. METHODS: Low-amplitude MV (80 Hz, amplitude 0.5 mm, duration 4 s), subthreshold for the tonic vibration reflex, was applied to the right extensor carpi radialis muscle (ECR). MEPs were elicited (0.5, 3 and 5 s after MV onset) in the left and right ECR and flexor carpi radialis muscle (FCR) by TMS (120% of threshold at rest) to the left and right hemisphere, respectively. RESULTS: During MV of right ECR the left ECR revealed a slight non-significant augmentation of MEPs. In contrast, the left FCR showed a gradual depression of MEPs with ongoing MV and at 3 s the reduction of MEPs was significant. The time course of MEP changes in left FCR correlated with the facilitation of the vibrated right ECR. Post-vibration MEPs at 1 s after the offset of MV were still significantly decreased. CONCLUSIONS: The study demonstrates crossed effects of MV on motor cortex excitability, suggesting transcallosal MEP modulation.
Authors: Thomas Lapole; John Temesi; Philippe Gimenez; Pierrick J Arnal; Guillaume Y Millet; Michel Petitjean Journal: Exp Brain Res Date: 2014-11-05 Impact factor: 1.972
Authors: Fernando Martínez; Jacobo A Rubio; Domingo J Ramos; Paula Esteban; Susana Mendizábal; Fernando Jiménez Journal: Int J Sports Phys Ther Date: 2013-02
Authors: John G Milton; Toru Ohira; Juan Luis Cabrera; Ryan M Fraiser; Janelle B Gyorffy; Ferrin K Ruiz; Meredith A Strauss; Elizabeth C Balch; Pedro J Marin; Jeffrey L Alexander Journal: PLoS One Date: 2009-10-20 Impact factor: 3.240