Mapping direct corticofugal motor and premotor projections with nTMS

Introduction: The human motor system has for many years been subject to extensive studies. Its function and properties became a matter of intensive debate after Penfield first disclosed several motor areas with direct cortical stimulation (Penfield, 1952). Ablation studies in animals and lesion studies in humans then provided a better, yet incomplete, understanding of the function of the respective areas (Freund, 1985). Especially imaging studies have highlighted the importance of non-primary motor areas (NPMA) in motor learning and recovery from cortical or subcortical lesions of the motor system (Chen, Cohen H…