Changes in corticospinal excitability with short-duration high-frequency electrical muscle stimulation: a transcranial magnetic stimulation study

Abstract

[Purpose] Afferent input caused by electrical stimulation of a peripheral nerve or a muscle modulates corticospinal excitability. However, a long duration of stimulation is required to induce these effects. The purpose of this study was to investigate the effect of short-duration high-frequency electrical muscle stimulation (EMS) on corticospinal excitability through the measurement of motor evoked potentials (MEP) in young healthy subjects. [Subjects] Eleven healthy right-handed subjects participated in this study. [Methods] EMS was applied to the abductor pollicis brevis (APB) muscle at 100 Hz with a pulse width of 100 μs for 120 s. The intensity of stimulation was just below the motor threshold. Transcranial magnetic stimulation was applied over the motor cortex, and MEP were recorded from the APB before, and immediately, 10, and 20 min after EMS. [Results] In the APB muscle, the MEP amplitude significantly decreased after EMS, and this effect lasted for 20 min. [Conclusion] The excitability of the corticospinal tract decreased after short-duration high-frequency EMS, and the effect lasted for 20 min. These results suggest that even short duration EMS can change the excitability of the corticospinal tract.

Effect of high-frequency repetitive transcranial magnetic stimulation on motor cortical excitability and sensory nerve conduction velocity in subacute-stage incomplete spinal cord injury patients

“…Ragert et al 12 ) reported that 5 Hz rTMS induced sustained increases of somatosensory cortex excitability, and Pleger et al 13 ) found that rTMS of the somatosensory cortex improved tactile discrimination and enhanced somatosensory cortex activation and that changes in primary motor cortex were negatively correlated with gains in discrimination ability. These results support the notion that rTMS augments sensory recovery in subacute -stage patients when they are treated within 6 months of SCI 14 , 15 ) . The present study has some limitations.…”

Insights About the Neuroplasticity State on the Effect of Intramuscular Electrical Stimulation in Pain and Disability Associated With Chronic Myofascial Pain Syndrome (MPS): A Double-Blind, Randomized, Sham-Controlled Trial

“…Both indicate a reduction in the excitability of the motor cortex, as well as lower facilitation of the transmission at corticospinal neurons. These results showed that electrical stimulation of peripheral nerves could modulate cells of cortical networks ( Miyata and Usuda, 2015 ). The MEP amplitude reflects the ratios of glutamine/glutamate and GABA/glutamate in the corresponding primary motor cortex.…”

High-Frequency External Muscle Stimulation Reduces Depressive Symptoms in Older Male Veterans: A Pilot Study

“…Besides peripheral mechanisms, a portion of EMS effects may arise from central mechanisms, whereby spinal motoneurons are recruited through the evoked sensory volley. 50 Several studies using TMS have suggested that EMS can induce changes in corticospinal excitability 51 -53 and interhemispheric inhibition. 54 Finally, other factors of EMS possibly affecting depression include mitochondrial function and release of antioxidant enzymes.…”