The postmigrational development of polymicrogyria documented by magnetic resonance imaging from 31 weeks' postconceptional age

We report the case of a 27-week premature infant in whom magnetic resonance imaging (MRI) at 4 postnatal weeks (postconceptional age, 31 weeks), term, and 6 months of age documented the postnatal postmigrational evolution of bilateral perisylvian polymicrogyria. The polymicrogyria was readily detect ed by ultrafine 1.5-mm coronal slices on three-dimensional, Fourier-transfo rmed, spoiled gradient-recalled and T2-weighted MRI sequences. These MRI se quences provide the first in vivo documentation of the postmigrational evol ution of polymicrogyria. The likelihood that the polymicrogyria was related to an ischemic encephaloclastic mechanism is supported by the simultaneous occurrence of periventricular leukomalacia.