Stenogyria

Stenogyria (stenos=narrow) refers to the packing of small gyri with shallow sulci and preservation of the general sulcal pattern. It is the most common cortical malformation described in Chiari II and is seen predominantly in the posterior and medial portion of the hemispheres.

On histological evaluation, stenogyric brain demonstrates normal cortical organization (in contrast to polymicrogyria). There is typically thinning of the underlying white matter.

References

Miller E, Widjaja E, Blaser S, Dennis M, Raybaud C. The old and the new: supratentorial MR findings in Chiari II malformation. Childs Nerv Syst. 2008 May;24(5):563-75.