Figure 3.

Intracortical Excitability. Mean values at the principal time points are shown for 3 measures of intracortical excitability: (A) SICI, (B) ICF, and (C) LICI. The value shown in each case represents the percentage change of the response to a TS in the presence of a CS: thus 100% would denote no inhibition or facilitation (shown as a dotted line). None of these values were significantly different from the healthy control group at individual time points (unpaired t-tests, values corrected for multiple comparisons). No parameter showed a significant time × hemisphere interaction. A mean value across all time points was thus calculated in each patient (and each parameter and hemisphere). This mean value is significantly raised compared with the normal group in the AH for SICI and LICI (unpaired t-tests: * P < 0.05). This suggests that these forms of intracortical inhibition are weak in the AH (i.e., increased excitability to paired pulse stimuli). The values for SICI and LICI also appear raised in the UH but are not significantly different from the healthy control group.