title: Increased somatosensory neuromagnetic fields ipsilateral to lesions in neurosurgical patients.
abstract: This study is aimed to determine whether the presence of a tumor in close proximity to the somatosensory cortex of the post-central gyrus affects the response evoked from such an area by painless tactile stimulation, recorded by MEG. The main finding of this study is that somatosensory evoked field strengths from cortex ipsilateral to and abutting an intracranial tumor are significantly elevated compared with either contralateral control fields, or with somatosensory evoked fields elicited from cortex ipsilateral to, but distant from tumors (typically involving language areas, such as inferior frontal lobe). Biophysical and biochemical explanations implicate hyperactivity of cortical neurons close to the tumor, suggesting a possible role of MEG as a measure of tumor infiltration.
authors.affiliation: Box 0628, Biomagnetic Imaging Laboratory, Department of Radiology, University of California, San Francisco 94143, USA.
authors.forename: Timothy P L
authors.initials: TP
authors.lastname: Roberts
authors.forename: Quy
authors.initials: Q
authors.lastname: Tran
authors.forename: Paul
authors.initials: P
authors.lastname: Ferrari
authors.forename: Mitchel S
authors.initials: MS
authors.lastname: Berger
mesh_terms: D001932:Brain Neoplasms / Q000503:physiopathology / Q000601:surgery; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005625:Frontal Lobe / Q000502:physiology / Q000503:physiopathology; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods* / Q000706:statistics & numerical data; D011300:Preoperative Care / Q000379:methods; D013003:Somatosensory Cortex / Q000473:pathology / Q000502:physiology / Q000503:physiopathology* / Q000601:surgery*