Holoprosencephaly Variant

The middle interhemispheric variant of holoprosencephaly.

BACKGROUND AND PURPOSE The middle interhemispheric variant of holoprosencephaly (MIH) is a rare malformation in which the cerebral hemispheres fail to divide in the posterior frontal and parietal regions. We herein describe the structural abnormalities of the brain in a large group of patients with MIH, compare these features with those of classic holoprosencephaly (HPE), and propose a developm...

Prenatal MR findings of the middle interhemispheric variant of holoprosencephaly.

We report a case of the middle interhemispheric variant of holoprosencephaly (MIH) with noncleavage of the posterior portion of the frontal lobes and the parietal regions in a fetus at 22 weeks' gestation. To our knowledge, this is the first case of the rare MIH variant to be diagnosed in utero by use of ultrafast MR imaging and one of the few such reports to document gross and microscopic path...

Middle interhemispheric variant of holoprosencephaly associated with diffuse polymicrogyria.

An 11-month-old boy was discovered to have a cleft palate, club foot, hypospadias, and myoclonic seizures. No in utero exposure to teratogens was identified. Brain MR imaging revealed a middle interhemispheric fusion variant of holoprosencephaly, diffuse polymicrogyria, and a hypoplastic brain stem; this was a distinctly unusual association of findings. We hypothesize that an unknown genetic fa...

Holoprosencephaly

Holoprosencephaly

Holoprosencephaly (HPE) is a complex brain malformation resulting from incomplete cleavage of the prosencephalon, occurring between the 18th and the 28th day of gestation and affecting both the forebrain and the face. It is estimated to occur in 1/16,000 live births and 1/250 conceptuses. Three ranges of increasing severity are described: lobar, semi-lobar and alobar HPE. Another milder subtype...