ANOMALOUS CEREBRAL-DOMINANCE - NEUROBEHAVIORAL STUDIES AND 3-DIMENSIONAL MAGNETIC-RESONANCE-IMAGING

Numerous cases of atypical cerebral lateralization have appeared in th e literature, yet these are heterogeneous and often fail to illuminate causal mechanisms. We evaluated neurobehavioral and neuroanatomical a symmetries in a 32-year-old woman with insulin-dependent diabetes mell itus, nonspecific immune dysfunction, and premature birth who develope d Broca's aphasia, Gerstmann's syndrome, hemispatial neglect, and rece ptive paralinguistic impairments following a right frontoparietal infa rction. She performed five out of seven tasks with her right hand, inc luding writing. Using three-dimensional reconstructions of magnetic re sonance images, we quantified the sizes of the left and fight planum t emporale (PT) and found her fight PT to be larger than her left, a pat tern associated with left-handedness. The presence of this structural asymmetry, which is known to develop prenatally, suggests that the fac tors responsible for this individual's anomalous neurobehavioral profi le were present in the prenatal environment.