Neuromagnetic localization of N15, the initial cortical response to lip stimulus

The initial cortical response of the trigeminal somatosensory evoked magnet ic fields was measured for electrical stimulation of the lower lip in eleve n subjects. The stimulus frequency was 0.7 HI and stimulus intensity was ni ne times sensory threshold. The initial contralateral response was detected in 20 hemispheres at a latency of 14.6 +/- 1.3 ms and was named N15m. The equivalent current dipole of N15m was localized at the posterior bank of th e central sulcus with anterior-superior orientation, and inferior to the di pole of N20m for median nerve stimulation. NeuroReport 12:1-5 (C) 2001 Lipp incott Williams & Wilkins.