Functional MRI of human primary somatosensory and motor cortex during median nerve stimulation

• Published in: Clinical neurophysiology Vol. 110; no. 1; pp. 47 - 52
• Main Authors: Spiegel, J, Tintera, J, Gawehn, J, Stoeter, P, Treede, R.-D
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 1999; Elsevier Science
• Subjects: Adult; Biological and medical sciences; Brain Mapping; Electric Stimulation; Functional magnetic resonance imaging; Fundamental and applied biological sciences. Psychology; Human brain mapping; Humans; Magnetic Resonance Imaging; Median Nerve - physiology; Median nerve stimulation; Middle Aged; Motor cortex; Motor Cortex - physiology; Somatosensory cortex; Somatosensory Cortex - anatomy & histology; Somatosensory Cortex - physiology; Somatosensory evoked potential; Somesthesis and somesthetic pathways (proprioception, exteroception, nociception); interoception; electrolocation. Sensory receptors; Vertebrates: nervous system and sense organs; Functional magnetic resonance imaging; Somatosensory cortex; Median nerve stimulation; Human brain mapping; Somatosensory evoked potential; Motor cortex; Human; Motor pathway; Somesthetic pathway; Electrical stimulus; Central nervous system; Median nerve; Nuclear magnetic resonance imaging; Brain (vertebrata)
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/S0168-5597(98)00043-4

Objectives: Somatosensory evoked potential (SEP) studies suggested that some early cortical SEP components may be generated in the primary motor cortex (M1) rather than the primary somatosensory cortex (S1). Methods: We now used functional magnetic resonance imaging (fMRI) to study activation of S1 and M1 by electrical median nerve stimulation in healthy volunteers. Results: The hand areas of both S1 and M1 showed significant activation (correlation coefficients >0.45) in 7 of 9 subjects (activated volume S1>M1). For comparison, a sequential finger opposition task significantly activated S1 in 7 and M1 in all 9 subjects (activated volume M1>S1). Conclusions: These data show that the electrical stimuli used for SEP recording lead to a functional activation of S1 as well as M1.