Areas MT/V5 and their transcallosal connectivity in cortical dysplasia by fMRI.
A patient with unilateral focal cortical dysplasia with a significant impairment of visual motion perception within the contralateral hemifield was examined with fMRI. During hemifield visual motion stimulation primary visual cortex areas were activated contralaterally and deactivated ipsilaterally to the stimulated hemifield. Transcallosal visuo-visual interaction was further evident as bilateral activation in temporo-occipital areas that best correspond to the motion sensitive areas MT/V5. MT/V5 was displaced anteriorly, superiorly, and medially within the dysplastic hemisphere and separated into two distinct activation clusters. During visual motion stimulation the parieto-insular vestibular cortex showed signal decreases that agree with the concept of inhibitory visuo-vestibular interaction. Thus, fMRI is a suitable tool for detecting preserved function and transcallosal connections in patients with focal cortical dysplasia.
Department of Neurology, Ludwig-Maximilians University Munich, Klinikum Grosshadern, Marchioninistr. 15, D-81377 Munich, Germany. Eva.Riedel@nro.med.uni-muenchen.de
Eva
E
Riedel
Thomas
T
Stephan
Esther
E
Marx
Angela
A
Deutschländer
Roland
R
Brüning
Thomas
T
Brandt
D000328:Adult; D001927:Brain Diseases / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009039:Motion Perception / Q000502:physiology*; D017120:Nystagmus, Optokinetic / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D012640:Seizures / Q000209:etiology; D013997:Time Factors; D014793:Visual Cortex / Q000098:blood supply / Q000503:physiopathology*
D010100:Oxygen