title: Reproducibility and stability of neuromagnetic source imaging in primary somatosensory cortex.
abstract: The present study investigated the test-retest reliability of magnetoencephalography (MEG) source localization of somatosensory evoked fields (SEFs) over an extended time period. Five healthy subjects were stimulated pneumatically at the first and fifth digit in two sessions spaced several months apart. At each location 400 stimuli were presented. The validation of the results was performed by overlay of the dipole localizations into the individual anatomic structure of the subjects' cortex by the use of magnetic resonance images (MRIs). The source localizations of the SEF component were found to be highly reproducible. The mean standard deviation of the dipole locations of the first digit was 1.55 mm in the x-, 1.55 mm in the y- and 3.49 mm in the z-direction. The mean standard deviation of the fifth digit was 3.69 mm in the x-, 4.27 mm in the y- and 6.60 mm in the z-direction. These results support the use of MEG recordings combined with MRI as an adequate method to define the organization of the human primary somatosensory cortex and provide a useful approach to the rapid detection of neuroplasticity.
authors.affiliation: Human Cortical Physiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA. schaefem@ninds.nih.gov
authors.forename: Michael
authors.initials: M
authors.lastname: Schaefer
authors.forename: Nina
authors.initials: N
authors.lastname: Nöennig
authors.forename: Anke
authors.initials: A
authors.lastname: Karl
authors.forename: Hans-Jochen
authors.initials: HJ
authors.lastname: Heinze
authors.forename: Michael
authors.initials: M
authors.lastname: Rotte
mesh_terms: D000328:Adult; D000344:Afferent Pathways / Q000502:physiology; D001931:Brain Mapping / Q000379:methods*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015225:Magnetoencephalography / Q000379:methods*; D009473:Neuronal Plasticity / Q000502:physiology; D010812:Physical Stimulation; D015203:Reproducibility of Results; D013003:Somatosensory Cortex / Q000033:anatomy & histology / Q000502:physiology*; D014110:Touch / Q000502:physiology