Steady-state activation in somatosensory cortex after changes in stimulus rate during median nerve stimulation

Manganotti, Paolo; Formaggio, Emanuela; Storti, Silvia Francesca; Avesani, Mirko; Acler, Michele; Sala, Francesco; Magon, Stefano; Zoccatelli, Giada; Pizzini, Francesca; Alessandrini, Franco; Fiaschi, Antonio; Beltramello, Alberto

doi:10.1016/j.mri.2009.05.009

« Previous Next »Magnetic Resonance Imaging
Volume 27, Issue 9 , Pages 1175-1186, November 2009

Steady-state activation in somatosensory cortex after changes in stimulus rate during median nerve stimulation

Paolo Manganotti
- Department of Neurological and Vision Sciences, Section of Neurological Rehabilitation, “Gianbattista Rossi” Hospital, University of Verona, 37134 Verona, Italy
- Corresponding author. Tel.: +39 045 8124768; fax: +39 045 8027276.
Emanuela Formaggio
- Department of Neurological and Vision Sciences, Section of Neurological Rehabilitation, “Gianbattista Rossi” Hospital, University of Verona, 37134 Verona, Italy
- Department of Information Engineering, University of Padova, 35131 Padova, Italy
Silvia Francesca Storti
- Department of Neurological and Vision Sciences, Section of Neurological Rehabilitation, “Gianbattista Rossi” Hospital, University of Verona, 37134 Verona, Italy
Mirko Avesani
- Department of Neurological and Vision Sciences, Section of Neurological Rehabilitation, “Gianbattista Rossi” Hospital, University of Verona, 37134 Verona, Italy
Michele Acler
- Department of Neurological and Vision Sciences, Section of Neurological Rehabilitation, “Gianbattista Rossi” Hospital, University of Verona, 37134 Verona, Italy
Francesco Sala
- Department of Neurological and Vision Sciences, Section of Neurological Rehabilitation, “Gianbattista Rossi” Hospital, University of Verona, 37134 Verona, Italy
Stefano Magon
- Department of Neurosurgery, Section of Neuroradiology, University of Verona, 37134 Verona, Italy
Giada Zoccatelli
- Department of Neurosurgery, Section of Neuroradiology, University of Verona, 37134 Verona, Italy
Francesca Pizzini
- Department of Neurosurgery, Section of Neuroradiology, University of Verona, 37134 Verona, Italy
Franco Alessandrini
- Department of Neurosurgery, Section of Neuroradiology, University of Verona, 37134 Verona, Italy
Antonio Fiaschi
- Department of Neurological and Vision Sciences, Section of Neurological Rehabilitation, “Gianbattista Rossi” Hospital, University of Verona, 37134 Verona, Italy
- IRCCS “San Camillo” Hospital, 30126 Venice, Italy
Alberto Beltramello
- Department of Neurosurgery, Section of Neuroradiology, University of Verona, 37134 Verona, Italy

Received 12 January 2009; received in revised form 10 February 2009; accepted 6 May 2009. published online 23 July 2009.

Abstract

Passive electrical stimulation activates various human somatosensory cortical systems including the contralateral primary somatosensory area (SI), bilateral secondary somatosensory area (SII) and bilateral insula. The effect of stimulation frequency on blood oxygenation level-dependent (BOLD) activity remains unclear. We acquired 3-T functional magnetic resonance imaging (fMRI) in eight healthy volunteers during electrical median nerve stimulation at frequencies of 1, 3 and 10 Hz. During stimulation BOLD signal changes showed activation in the contralateral SI, bilateral SII and bilateral insula. Results of fMRI analysis showed that these areas were progressively active with the increase of rate of stimulation. As a major finding, the contralateral SI showed an increase of peak of BOLD activation from 1 to 3 Hz but reached a plateau during 10-Hz stimulation. Our finding is of interest for basic research and for clinical applications in subjects unable to perform cognitive tasks in the fMRI scanner.

Keywords: fMRI, SEP, BOLD, 3T, Stimulation frequency