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The modulatory effect of electrical stimulation on the excitability of the corticospinal tract varies according to the type of muscle contraction being performed.

Saito K, Sugawara K, Miyaguchi S, Matsumoto T, Kirimoto H, Tamaki H, Onishi H - Front Hum Neurosci (2014)

Bottom Line: Afferent input caused by electrical stimulation of a peripheral nerve increases corticospinal excitability during voluntary contractions, indicating that proprioceptive sensory input arriving at the cortex plays a fundamental role in modulating corticospinal excitability.A single pulse of electrical stimulation did not affect MEP amplitudes in any condition.These results show that the type of contraction should be considered when using electrical stimulation for rehabilitation in patients with central nervous system lesions.

View Article: PubMed Central - PubMed

Affiliation: Department of Physical Therapy, Niigata University of Health and Welfare Niigata, Japan ; Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan.

ABSTRACT
Afferent input caused by electrical stimulation of a peripheral nerve increases corticospinal excitability during voluntary contractions, indicating that proprioceptive sensory input arriving at the cortex plays a fundamental role in modulating corticospinal excitability. The purpose of this study was to investigate whether the effect of electrical stimulation on the corticospinal excitability varies according to the type of muscle contraction being performed. Motor-evoked potentials (MEPs) were elicited by transcranial magnetic stimulation (TMS) during a shortening contraction, an isometric contraction, or no contraction of the first dorsal interosseous (FDI) muscle. In some trials, electrical stimulation of the ulnar nerve was performed at 110% of the sensory threshold or 110% of the motor threshold prior to TMS. Electrical stimulation involved either a train of 50 pulses at 10 Hz or a single pulse. Shortening contraction with the train of electrical stimuli significantly increased MEP amplitudes, and the increase was dependent on the type of stimulation. Isometric contraction with the train of electrical stimuli and electrical stimulation without voluntary contraction did not affect MEP amplitudes. A single pulse of electrical stimulation did not affect MEP amplitudes in any condition. Thus, electrical-stimulation-induced modulation of corticospinal excitability varied according to the type of muscle contraction performed and the type of stimulation. These results show that the type of contraction should be considered when using electrical stimulation for rehabilitation in patients with central nervous system lesions.

No MeSH data available.


Related in: MedlinePlus

The effect of electrical stimulation without voluntary contraction on the excitability of the corticospinal tract. (A) Typical averaged motor-evoked potential (MEP) waveforms recorded in the FDI muscle. (B) The changes in the group mean MEP control ratio (n = 8) induced by the following experimental tasks: electrical stimulation (ES; above motor threshold, MT) without voluntary contraction (vol), ES (above sensory threshold, ST) without vol, single electrical pulse (MT) without vol, and single electrical pulse (ST) without vol, and a control trial using the resting motor threshold as the TMS intensity. The MEP amplitude was significantly higher after a train of electrical stimulation above sensory threshold than after single pulse above sensory threshold (p = 0.018) and at rest (p = 0.006).
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Figure 5: The effect of electrical stimulation without voluntary contraction on the excitability of the corticospinal tract. (A) Typical averaged motor-evoked potential (MEP) waveforms recorded in the FDI muscle. (B) The changes in the group mean MEP control ratio (n = 8) induced by the following experimental tasks: electrical stimulation (ES; above motor threshold, MT) without voluntary contraction (vol), ES (above sensory threshold, ST) without vol, single electrical pulse (MT) without vol, and single electrical pulse (ST) without vol, and a control trial using the resting motor threshold as the TMS intensity. The MEP amplitude was significantly higher after a train of electrical stimulation above sensory threshold than after single pulse above sensory threshold (p = 0.018) and at rest (p = 0.006).

Mentions: Figure 5A shows a typical MEP in the FDI from one participant during a train of electrical stimulation of the ulnar nerve without voluntary contraction, and Figure 5B shows the pooled data (n = 14). A one-way repeated-measures ANOVA revealed that there was a significant effect of the stimulation condition on the MEP control ratio [F(4.52) = 4.201, p = 0.005]. Post hoc analysis revealed that the MEP amplitude was significantly higher after a train of electrical stimulation above sensory threshold than that after a single pulse above sensory threshold (p = 0.018) and that at rest (p = 0.006).


The modulatory effect of electrical stimulation on the excitability of the corticospinal tract varies according to the type of muscle contraction being performed.

Saito K, Sugawara K, Miyaguchi S, Matsumoto T, Kirimoto H, Tamaki H, Onishi H - Front Hum Neurosci (2014)

The effect of electrical stimulation without voluntary contraction on the excitability of the corticospinal tract. (A) Typical averaged motor-evoked potential (MEP) waveforms recorded in the FDI muscle. (B) The changes in the group mean MEP control ratio (n = 8) induced by the following experimental tasks: electrical stimulation (ES; above motor threshold, MT) without voluntary contraction (vol), ES (above sensory threshold, ST) without vol, single electrical pulse (MT) without vol, and single electrical pulse (ST) without vol, and a control trial using the resting motor threshold as the TMS intensity. The MEP amplitude was significantly higher after a train of electrical stimulation above sensory threshold than after single pulse above sensory threshold (p = 0.018) and at rest (p = 0.006).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4199265&req=5

Figure 5: The effect of electrical stimulation without voluntary contraction on the excitability of the corticospinal tract. (A) Typical averaged motor-evoked potential (MEP) waveforms recorded in the FDI muscle. (B) The changes in the group mean MEP control ratio (n = 8) induced by the following experimental tasks: electrical stimulation (ES; above motor threshold, MT) without voluntary contraction (vol), ES (above sensory threshold, ST) without vol, single electrical pulse (MT) without vol, and single electrical pulse (ST) without vol, and a control trial using the resting motor threshold as the TMS intensity. The MEP amplitude was significantly higher after a train of electrical stimulation above sensory threshold than after single pulse above sensory threshold (p = 0.018) and at rest (p = 0.006).
Mentions: Figure 5A shows a typical MEP in the FDI from one participant during a train of electrical stimulation of the ulnar nerve without voluntary contraction, and Figure 5B shows the pooled data (n = 14). A one-way repeated-measures ANOVA revealed that there was a significant effect of the stimulation condition on the MEP control ratio [F(4.52) = 4.201, p = 0.005]. Post hoc analysis revealed that the MEP amplitude was significantly higher after a train of electrical stimulation above sensory threshold than that after a single pulse above sensory threshold (p = 0.018) and that at rest (p = 0.006).

Bottom Line: Afferent input caused by electrical stimulation of a peripheral nerve increases corticospinal excitability during voluntary contractions, indicating that proprioceptive sensory input arriving at the cortex plays a fundamental role in modulating corticospinal excitability.A single pulse of electrical stimulation did not affect MEP amplitudes in any condition.These results show that the type of contraction should be considered when using electrical stimulation for rehabilitation in patients with central nervous system lesions.

View Article: PubMed Central - PubMed

Affiliation: Department of Physical Therapy, Niigata University of Health and Welfare Niigata, Japan ; Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan.

ABSTRACT
Afferent input caused by electrical stimulation of a peripheral nerve increases corticospinal excitability during voluntary contractions, indicating that proprioceptive sensory input arriving at the cortex plays a fundamental role in modulating corticospinal excitability. The purpose of this study was to investigate whether the effect of electrical stimulation on the corticospinal excitability varies according to the type of muscle contraction being performed. Motor-evoked potentials (MEPs) were elicited by transcranial magnetic stimulation (TMS) during a shortening contraction, an isometric contraction, or no contraction of the first dorsal interosseous (FDI) muscle. In some trials, electrical stimulation of the ulnar nerve was performed at 110% of the sensory threshold or 110% of the motor threshold prior to TMS. Electrical stimulation involved either a train of 50 pulses at 10 Hz or a single pulse. Shortening contraction with the train of electrical stimuli significantly increased MEP amplitudes, and the increase was dependent on the type of stimulation. Isometric contraction with the train of electrical stimuli and electrical stimulation without voluntary contraction did not affect MEP amplitudes. A single pulse of electrical stimulation did not affect MEP amplitudes in any condition. Thus, electrical-stimulation-induced modulation of corticospinal excitability varied according to the type of muscle contraction performed and the type of stimulation. These results show that the type of contraction should be considered when using electrical stimulation for rehabilitation in patients with central nervous system lesions.

No MeSH data available.


Related in: MedlinePlus