These and other studies have motivated research investigating the therapeutic potential of noninvasive brain stimulation techniques in stroke recovery. A number of proof-of-principle therapeutic trials have been completed, with the results suggesting that excitatory brain stimulation to the lesioned hemisphere, or inhibitory brain stimulation to the unaffected hemisphere, may have beneficial effects in promoting recovery after stroke (Murase et al., 2004; Hummel et al., 2005; Khedr et al., 2005; Fregni et al., 2005, 2006a; Takeuchi et al., 2005; Kirton et al., 2008; Nowak et al., 2009; Emara et al., 2010).
