[A case of holoprosencephaly with parietal encephalocele].

Holoprosencephaly, as described by DeMyer, is a cerebral malformation in which the embryonic prosencephalon fails to divide into cerebral hemispheres. According to the degree of division in the prosencephalon, he classified holoprosencephaly into three types; alobar, semilobar and lobar type. We have experienced a case of holoprosencephaly with parietal encephalocele. The patient was admitted to our hospital 4 hours after birth because of parietal encephalocele. A radical operation was carried out and encephalocele was diagnosed histologically. After discharge from our hospital, his psychosomatic development was remarkably delayed. On Oct. 20, 1985, he was re-admitted for further examination. CT-scan and cerebral angiography showed characteristic findings. The classification of holoprosencephaly and dorsal cyst malformation is discussed. On encephalocele with holoprosencephaly, it is said that there may be an extra-calvarial extension of the dorsal sac or ventricular system. But, Hutchinson stated in his experience that first, a closure disorder of the neural tube caused encephalocele. And later a disorder of diverticularization produced the holoprosencephalic abnormality. He suggested that there were two independent disorders of organogenesis which might rarely occur in the same patient. We also reported a similar case of holoprosencephaly with parietal encephalocele which has some controversial problems.