Interhemispheric inhibition and mirror movements

Background: Interhemispheric inhibition (IHI) is thought to be important for the suppression of mirror movements (MM) during unimanual movements. In a previous study, we supported this view by showing that IHI correlates inversely with MM: the stronger IHI from the voluntarily active to the mirror motor cortex (M1), the less the amount of MM (Hübers & Ziemann 2004, Klin Neuro 35:155). In order to substantiate this role of IHI further, we applied focal repetitive transcranial magnetic stimulation (rTMS) to M1 to alter IHI and evaluate the consequences on MM. Methods: RTMS (1Hz, 900 pulses, 120% of resting motor t…