Table 2. Stimulator output was adjusted at the start of each experiment to elicit unconditioned MEPs of 1mV in the left and right FDI with the muscle at rest but 500ms prior to a low-level unimanual contraction of the right FDI.
Unconditioned test MEPs of 1mV were elicited in the right FDI by applying single monophasic magnetic stimuli to the left motor cortex (M1) using a Bistim module (Test Pulse). Conditioning MEPs of 1mV were elicited in the left FDI by applying single biphasic magnetic stimuli to the right M1 to activate the interhemispheric inhibitory pathway using a Rapid2 stimulator (Conditioning Pulse). Stimulator intensities and elicited MEPs were matched across days however the stimulator output required to elicit 1mV conditioning stimuli on the Fatigue+No stim day was slightly elevated indicating reduced excitability of the ipsilateral M1 at baseline. Data are presented as mean±sd.
| Test Pulse (Left M1) | Conditioning Pulse (Right M1) | |||
|---|---|---|---|---|
| Day | Stimulator Output (%MSO, Bistim) | MEP Amplitude (mV) | Stimulator Output (%MSO, Rapid2) | MEP Amplitude (mV) |
| Fatigue+Stim | 45.7±6.6 | 1.2±0.6 | 63.7±6.2 | 0.97±0.4 |
| Fatigue+No Stim | 47.7±6.3 | 1.17±0.5 | 67.4±6.9* | 1.1±0.8 |
| No Fatigue+Stim | 45.8±5.5 | 0.97±0.35 | 65.2±8.3 | 1.05±0.4 |
| No Fatigue+ No Stim | 45.1±7.0 | 1.28±0.45 | 64.3±7.5 | 1.17±0.75 |
* indicates a significance (Fishers LSD post hoc, p<0.05).