Localization of sensorimotor cortex by using functional magnetic resonance imaging: comparison between finger tapping and palm scratching in normal volunteer.

The purpose of this study was to compare the location and intensity of activation of the sensorimotor cortex between finger tapping and palm scratching paradigms in normal volunteers and to consider using passive task instead of motor task in patients who are unable to perform motor task. Multishot echo-planar T2*-weighted imaging sequences at the level of the sensorimotor cortex were performed in axial plane during finger tapping and palm scratching paradigms in 13 normal volunteers. The authors found that the location of activation was slightly posterior only in bilateral passive task compared to bilateral motor task but there was no statistical significance. However, this observation was not seen in unilateral tasks. The intensity of activation of both motor and passive tasks was comparable. The authors conclude that in normal volunteers passive task (palm scratching) can be used instead of motor task (finger tapping) to localize the location of the sensorimotor cortex.