Visual field plasticity in a female with right occipital cortical dysplasia

Brain plasticity refers to its ability to recover after damage. Visual fiel d plasticity is not well recognized. We report a 12-year-old female who fir st presented with recurrent seizures and was subsequently found to have a l arge, right occipital cortical dysplasia on magnetic resonance imaging. Her visual field by Goldmann perimetry was totally normal. Visual-evoked poten tial studies revealed the left hemifield P100 response was detected maximal ly at the right temporal and parietal regions. A weak but reproducible righ t hemifield P100 response was located at the right medial skull base. Funct ional magnetic resonance imaging with flashlight stimulation revealed cereb ral activity mainly at the right posterior temporal and parietal lobes and left occipital lobe. These studies suggested that the left hemifield functi on was located at the right posterior temporal and parietal lobes. The left occipital lobe may also have been reorganized, with a P100 vector pointing out from its inferiomedial base. We reviewed other related reported cases. We believe that visual-evoked potential studies and visual functional magn etic resonance imaging should be performed more liberally for recognition o f visual field plasticity. (C) 2000 by Elsevier Science Inc. All rights res erved.