Table 3.
Measurements of motor cortex parameters using transcranial magnetic stimulation (n = 47)
|
Cortical excitability measures |
|
|
||
|---|---|---|---|---|
| |
Before QST evoked pain |
After QST evoked pain |
||
| Mean±SD | Median (Q25, Q75) | Mean±SD | Median (Q25, Q75) | |
| Motor Threshold (MT) |
42.65 (7.39) |
41 (37.5, 46) |
---- |
----- |
| Motor evoked potential (mV) |
1.74 (0.71) |
1.53 (1.27, 2.20) |
2.13 (0.93) |
1.93 (1.58, 2.58) |
| Intracortical Facilitation (ratio: ICF/test stimulus) |
1.16 (0.42) |
1.11 (1, 1.23) |
1.25 (0.59) |
1.15 (0.92, 1.44) |
| Short Interval Intracortical Inhibition (ratio: SICI/test stimulus) |
0.32 (0.14) |
0.28 (0.22, 0.35) |
0.34 (0.19) |
0.29 (0.21, 0.43) |
| Cortical Silent Period (CSP) | 65.42 (19.64) | 66.25 (47.9, 79.31) | 66.16 (20.16) | 68.30 (50.59, 81.71) |
(Motor evoked potential: MEP); Interquartile interval (Q); Intra-cortical inhibition (ICI) expresses the relationship between the amplitude of wave and motor evoked potentials (relative amplitude, express in%), at inter-stimuli intervals (ISIs) of 2 ms with paired-pulse. The first is a sub-threshold stimulus [80% of the rest motor threshold (rMT)] followed by the second one which is a suprathreshold stimulus (130% rMT).(B)Cortical silent period (CSP) expressed in milliseconds (ms);(C)Motor-evoked potentials (MEP) expressed in mV, evoked by a stimulus of 130% the intensity of the rMT, and should have peak-to-peak MEP amplitude of at least 1 mV.