There are two mechanisms by which rTMS can decrease cortical and corticospinal excitability (Chen et al., 1997; Maeda et al., 2000; Muellbacher et al., 2000; Fierro et al., 2001; Touge et al., 2001; Fitzgerald et al., 2002; Romero et al., 2002; Tsuji and Rothwell, 2002) while increasing rCBF (synaptic activity).