Anterior basal encephalocele of the neonatal and infantile period.
Diagnosis of occult basal encephalocele is not difficult if the peculiar clinical and radiological signs of this anomaly are borne in mind. Recent surgery for transsphenoidal encephalocele has had better results than realized. However, high surgical risks may still be encountered in transsphenoidal encephalocele of the early infantile period, because the pituitary-hypothalamic structures are usually incorporated in the herniated encephalocele of this age group. Surgical indications for and operative approaches to transsphenoidal encephalocele in the infantile period are discussed on the basis of the authors' failure in transcranial repair, which resulted in early postoperative death due to hypothalamic dysfunction. Reviewing the reported cases of anterior basal encephalocele, a high correlation between transsphenoidal encephalocele, particularly in the pediatric age group, and allied malformations of the face, eye, and brain was disclosed. This characteristic malformation complex may be explained by a common pathogenetic mechanism operating in the embryonal period at about the stage of the anterior neuropore closure and occurring in the ventral surface of the cephalic end of the neural tube. Three cases of transsphenoidal encephalocele diagnosed in the neonatal period with progressive obstruction in the nasopharyngeal airway are also reported. A characteristic malformation complex consisting of median cleft face syndrome, optic nerve dysplasia, and agenesis of the corpus callosum was associated in two cases; the other patient had an extremely rare combination of septooptic dysplasia. Two patients died pre- and postoperatively, respectively; the other patient did not undergo operation because of grave multiple anomalies.