The purpose of this report is to analyze the long-term outcome in hydrocephalic children treated by shunt placement and in particular their psycho-intellectual development. In the case of shunt placement postoperative mortality is virtually nil, and the overall mortality rate after 10 years of follow-up has been reduced to less than 5%. Morbidity, in contrast, is far from satisfactory. This study was conducted in 129 consecutive children with nontumorous hydrocephalus who underwent a first shunt insertion before the age of 2 years between 1979 and 1982 and who were followed up for at least 10 years. The final neurological examination revealed a motor deficit in 60%, visual or auditory deficits in 25%, and epilepsy in 30%. The final IQs were above 90 in 32% of the children, between 70 and 90 in 28%, between 50 and 70 in 19%, and lower than 50 in 21%. Integration into the normal school system was possible for 60% of the children, but half of them were 1-2 years behind their age group or having difficulties; 31% were attending special classes or were in institutions; and 9% were considered ineducable. The presence of behavioral disorders was a determinant factor for scholastic and social integration. Such disorders were frequent, and were characterized as severe in 30%. A relationship between final outcome and etiology, initial ventricular size, and epilepsy was observed. These results are used as the basis of a discussion on how morbidity might be improved.

The purpose of this study was to determine the respective parts played by cerebral hemisphere irradiation, posterior fossa irradiation, and surgery in the poor late functional results often observed in children treated for medulloblastoma. To do this we compared the intellectual outcome in a series of 59 children operated on for medulloblastoma, who had received whole-brain irradiation, to that observed in a series of 37 children operated on for ependymoma of the posterior fossa, who had received radiotherapy only on the posterior fossa. Only patients who had survived for more than 2 years without recurrence were included. At the assessment 1 year after treatment, intellectual outcome was somewhat better in the ependymoma group, but the difference was not statistically significant. At the long-term follow-ups at 5 and 10 years the results remained stable in the children treated for ependymoma, around 60% having an IQ above 90, whereas the intellectual level of the children treated for medulloblastoma was seen to have deteriorated progressively: 20% had an IQ above 90 5 years after treatment and only 10% at the 10-year follow-up. This progressive degradation is most likely due to the irradiation of the cerebral hemispheres, as this prophylactic irradiation constituted the only difference between the two groups. Moreover, irradiation to the posterior fossa did not seem to affect intellectual functions, since in the group of children with ependymomas the proportion of IQs above 90 was high and remained stable over the years. Surgery was certainly responsible for some poor results. The percentage of IQs above 90 observed 1-2 years after treatment was between 70 and 80 when no postoperative complications occurred, and only between 20-40% in the presence of postoperative complications. Postoperative aggravation was in most cases related to a brain-stem lesion. These results encourage the reduction, when possible, of irradiation to the cerebral hemispheres and underline the importance of the quality of surgery.

Dentate nuclei lesions are major risk factors of motor and cognitive impairments in both cerebellar BT and MT.