Holoprosencephaly

Abstract

One hundred human embryos, five foetuses and seven infants with holoprosencephaly were studied. In the embryos, diagnostic criteria consisted of: 1) disturbed diverticulation of the rostral neural canal; and 2) presence of median facial anomaly. Developmental stages of the holoprosencephalic embryos ranged from the Carnegie stage 14 to 23. For the diagnosis of holoprosencephaly in foetuses characteristic facial anomalies had to be relied on. In infants, facial anomalies were present in only three out of seven patients. The necessity to use proper diagnostic aids was emphasized. In angiograms, peculiar azygos anterior cerebral artery is diagnostic of alobar and semilobar holoprosencephaly while dysgenesis of the deep venous system is helpful for the diagnosis of lobar holoprosencephaly. Air ventriculography and CAT scan revealed broader interventricular communication, presence of the dorsal sack and/or absence of the interhemispheric fissure. The types of holoprosencephaly were diagnosed as alobar in four, semilobar in one and lobar in two cases. Apparent hydrocephalus was not found in the malformed embryos. It was present in two out of five holoprosencephalic foetuses, and six out of seven newborn patients. The hydrocephalic process seems to begin in the foetal period in most cases. From the review of 89 reported cases, hydrocephalus does not seem common in the alobar and the semilobar type, but it seems almost always present in lobar holoprosencephaly. The prognosis of lobar holoprosencephaly does not seem so desperate if hydrocephalus is successfully treated. The importance of holoprosencephaly, especially its lobar type, in neurosurgical practice was emphasized.