derencephaly

[ dĕr′ĕn-sĕfə-lē ]

n.

A malformation in which the skull bones are underdeveloped and the cervical vertebrae are bifurcated, with a rudimentary brain usually resting in the cleft.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.