Table 1 Anatomic classification of HPE -Different levels of severity [1] [6]
From: Holoprosencephaly
ALOBAR (complete) | Small single forebrain ventricle No interhemispheric division Absence of olfactory bulbs and tracts Absence of corpus callosum Non separation of deep gray nuclei |
SEMI-LOBAR | Rudimentary cerebral lobes Incomplete interhemispheric division Absence or hypoplasia of olfactory bulbs and tracts Absence of corpus callosum Varying non separation of deep gray nuclei |
LOBAR | Fully-developed cerebral lobes Distinct interhemispheric division Midline continuous frontal neocortex Absent, hypoplasic or normal corpus callosum Separation of deep gray nuclei |
MIHF | Failure of separation of the posterior frontal and parietal lobes Callosal genu and splenium normally formed Absence of corpus callosum Hypothalamus and lentiform nuclei normally separated Heterotopic gray matter |