Bilateral perisylvian polymicrogyria

MRI of a patient, age 27 years, with pseudobulbar palsy, mental delay, and chronic seizures. Sagittal (A) and transverse axial (B) T1-weighted and transverse axial (C) and coronal (D) T2-weighted MRIs show coarse polymicrogyria (p) centered in both shallow sylvian fissures and extending to the occipital poles. Polymicrogyria cortex is slightly thick, with an irregular "bumpy" outer and inner surface.

Bilateral perisylvian polymicrogyria is the most common polymicrogyria syndrome and is mainly sporadic; it may be caused by in utero infection (most commonly CMV) or ischemia.