Paraesthesia elicited by repetitive magnetic stimulation of the postcentral gyrus.

Repetitive transcranial magnetic stimulation of short duration (0.3 or 0.6 s, 20 Hz) evoked paraesthesia similar to that caused by repetitive electrical stimulation. Since the points eliciting the paraesthesia were approximately 2 cm posterior from those eliciting motor responses, the paraesthesia stemmed from direct excitation of the post-central gyrus. The paraesthesia showed somatotopical representation: the point eliciting the paraesthesia in the leg was separated from the point eliciting the paraesthesia in the hand 2.9 cm medially in one subject, and 1 cm posteriorly and 1 cm medially in the other subject. Repetitive transcranial magnetic stimulation provides a painless, noninvasive method for mapping cortical sensory representation in humans.