Hydrocephalus and its various subtypes

Mr．　President！　Colleagues and Guests！

　I am greatly impressed with Dr．　Pudenz'　excellent　presentation of his own invention, the ventriculo—atrial shunt．　Since I am asked by President Mitsuno　to discuss his paper, I would like to add our small　experiences of the procedure and would then refer　to the subtypes of infantile hydrocephalus, namely，　hydroencephalodysplasia and Chiari-Arnold syndrome．