We present an MRI-based anatomic analysis of a series of seven @entity1 brains with the semilobar form of @entity10146 . The analysis defines a set of common descriptors for a @entity7944 which is uniform for the set of seven brains. The core of the @entity154 is a rostro-caudally aligned midline gray matter 'seam' that extends from the @entity4519 -suprachiasmatic junctional region to abut the posterior aspect of the callosal commissure. The seam forms the ventricular roof throughout its extent. Rostrally it is formed by the conjoined heads of caudate/accumbens nuclei. It continues caudally as a gray matter bridge in the fundus of the interhemispheric fissure, where it bridges right and left neocortex. Fornix, septal nuclei and septal limb of the choroid plexus are absent, and the @entity4519 ventricles communicate with the diencephalic via open septal limbs of the choroid fissures. By contrast, the temporal limb of hippocampal formation and the choroid plexus are normal and the temporal limb of the choroid fissure is closed. This topological @entity154 of conjoined left and right cortical and nuclear gray matter into a midline seam and absent septal structures is thus confined to the region of the midline @entity4519 hemisphere evagination. Total @entity4519 growth is strongly correlated with the length of this topologically abnormal midline @entity4519 segment. The set of findings is consistent with graded failure of induction of rostral to caudal specification in the midline rostral @entity4519 zone.

Semilobar XXXX with midline 'seam': a topologic and morphogenetic model based upon MRI analysis.

@entity1 :: ('9606', 'Species') :: ['human'] @entity154 :: ('MESH:D000013', 'Disease') :: ['anomaly'] @entity7944 :: ('MESH:C536309', 'Disease') :: ['pattern of topological anomaly'] @entity10146 :: ('MESH:D016142', 'Disease') :: ['holoprosencephaly'] @entity4519 :: ('MESH:C536954', 'Disease') :: ['telencephalic']
@entity10146 :: (MESH:D016142,Disease) :: ['holoprosencephaly']
