title: Post-apoplectic reorganization of cortical areas processing passive movement and tactile stimulation--a neuromagnetic case study.
abstract: Magnetoencephalography (MEG) was used in a patient with right centro-parietal stroke to investigate the cortical processing of tactile pneumatic stimulation and passive movement of the impaired left and unaffected right-hand index finger. Source localization of somatosensory evoked magnetic fields (SEF) recorded 2 weeks after infarction demonstrated a spatial displacement of the contralateral SI generators in the affected hemisphere. The distance between SI sources activated by either stimulation technique was noticeably enlarged in comparison to the left hemisphere and to previous data from 12 healthy subjects. Follow-up MEG after 6 months revealed a closer spatial arrangement of the two modality-specific SEF generators and a diminution of the interhemispheric asymmetry of proprioception-related SI sources. The topographical alterations were accompanied by clear clinical improvement of both joint position sense and tactile sensation. The occurrence of ipsilateral SI activity following passive movement of only the impaired index finger might suggest a disinhibition of subthreshold, transcallosal excitatory pathways.
authors.affiliation: Division of Neuroradiology, Department of Neurosurgery; University of Erlangen-Nuernberg, Schwabachanlage 6, 91054 Erlangen, Germany. katrin.druschky@neuro.imed.uni-erlangen.de
authors.forename: Katrin
authors.initials: K
authors.lastname: Druschky
authors.forename: Martin
authors.initials: M
authors.lastname: Kaltenhäuser
authors.forename: Cornelia
authors.initials: C
authors.lastname: Hummel
authors.forename: Achim
authors.initials: A
authors.lastname: Druschky
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Huk
authors.forename: Bernhard
authors.initials: B
authors.lastname: Neundörfer
authors.forename: Hermann
authors.initials: H
authors.lastname: Stefan
mesh_terms: D002545:Brain Ischemia / Q000503:physiopathology*; D005073:Evoked Potentials, Somatosensory; D005385:Fingers; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D020521:Stroke / Q000503:physiopathology*; D014110:Touch / Q000502:physiology*