The infundibulum of the hypophysis in hydrocephalus

This study describes the normal gross anatomy of the infundibulum and compares it with those in untreated and treated hydrocephalus. The infundibular length is 2-8 mm long (mean 5 mm) and shows little or no increase in length after birth. In treated hydrocephalic brains it has a mean length of 4 mm and in the untreated cases a mean length of 2.4 mm. The normal anterior angle is 65 degrees-120 degrees (mean 90 degrees). The treated cases range between 40 degrees to 130 degrees (mean 81 degrees) whereas the range of the untreated cases is even wider at 0 degrees to 160 degrees (mean 88 degrees). There is no correlation in the hydrocephalic groups between the angle and the length, angle and cortical thickness or length and cortical thickness. The changes observed appear to depend on the stage and severity of the hydrocephalus the caudal and cranial displacement of the brain stem. In only two of the fifty hydrocephalic brains examined did the infundibulum have a "normal" length, thickness and angle. Histological and cytochemical examination of the hypothalamus, infundibulum and hypophysis is needed to correlate the clinical findings of frequent endocrine abnormalities with histological ones.