Magnetic stimulation of the brain: starting or stopping.
A very brief magnetic pulse is able to stimulate cortical neurons through the intact scalp. It can elicit movement of a limb by activation of pyramidal cells either directly or via interneurons. When making a voluntary movement, a corresponding program of the task is thought to be compiled beforehand. In patients with ideomotor apraxia who can not perform a task, a lesion of the left hemisphere is frequently found. A magnetic cortical stimulus given directly before a movement is executed is known to delay the onset without altering the pattern. When it will become feasible to deliver a localized stimulus to one hemisphere, this will induce a temporary pause in that area and thus simulating a lesion in intact brain. In this way information can be gathered on the localization of voluntary action in intact brains.
van der Kamp
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Department of Neurology, University Hospital, Leiden, The Netherlands.
D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004574:Electromagnetic Fields; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D009046:Motor Neurons / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology; D009132:Muscles / Q000294:innervation*; D011712:Pyramidal Tracts / Q000502:physiology*