TASK-RELATED ACTIVATIONS IN HETEROTOPIC BRAIN MALFORMATIONS - A PET STUDY

POSITRON emission tomography (PET) studies have shown normal or elevat ed levels of glucose metabolism in neuronal heterotopia, raising the i ssue of potential participation of heterotopic neurons in cognitive pr ocessing. We studied three patients with heterotopic malformations, us ing [O-15]water PET and experimental conditions selected according to the location of the malformations. Task performance was associated wit h blood flow increases of > 17% within the heterotopia in each patient . In two, these occurred in left frontal heterotopia during sentence g eneration. In the third patient, activations for facial and visuospati al discrimination and picture naming were found in a right posterior h eterotopion. Our findings may reflect participation of heterotopia in cognitive function and suggest that heterotopic neurons synapse with n eurons in other brain regions. NeuroReport 9: 2527-2533 (C) 1998 Rapid Science Ltd.