Differentiation of Motor Cortical Representation of Hand Muscles by Navigated Mapping of Optimal TMS Current Directions in Healthy Subjects

• DOI: 10.1097/wnp.0b013e31829dda6b
• Publication Date: 2013-08-03T09:59:47Z
• Authors: Shahid Bashir; Jennifer M. Perez; Jared C. Horvath; Alvaro Pascual-Leone
• Keywords: Central sulcus; Neuronavigation; Brain mapping

Summary: The precision of navigated transcranial magnetic stimulation (TMS) to map the human primary motor cortex may be effected by direction TMS-induced current in brain as determined orientation coil. In this study, authors investigated effect directionality on output mapping using stimulation. goal study was determine optimal coil (and, thus, induced current) activate hand musculature representations relative each subject's unique neuroanatomical landmarks. studied maps for first dorsal interosseous, abductor pollicis brevis, and digiti minimi muscles 10 normal volunteers. Monopolar pulses were delivered through a figure-of-eight–shaped TMS coil, evoked potentials recorded electromyography. At targeted region, systematically rotated induction largest potentials. These directions expressed an angle central sulcus. Consistency assessed repeating entire procedure two different occasions across subjects. demonstrate that systematic optimization guided MRI-based neuronavigation improves resolution cortical with TMS.