Effect of Cortical Magnetic Stimulation on cognition and upper extremity reaction time

Cortical Magnetic Stimulation (CMS) is a painless, noninvasive tool useful for mapping cortical organization in a clinical environment. A recent report warned of temporary impairment of cognitive function coupled with a reduction in reaction time after CMS, while previous assessment of cognitive function before and after CMS revealed no effects at all. We have designed a study to determine if clinical mapping investigations employing CMS have any effect on short term attention, concentration, memory, or upper extremity motor reaction time, and if any observed effects are due to the presence of cortical stimulation. Data presented show no significant changes in cognitive function or reaction time after CMS but a trend toward reduced reaction times is noted.