Thirteen cases of the Dandy-Walker syndrome were seen over a period of 12 years. In this study their preoperative evaluation, surgical treatment and outcome is reviewed. The incidence of hydrocephalus in the series was 77%. Eight of the patients had associated central nervous system anomalies, and the need to identify these abnormalities is stressed. Because the two conditions require different surgical management, during the diagnostic work-up it is crucial to differentiate between the Dandy-Walker syndrome and extra axial cerebrospinal fluid (CSF) filled cysts, and to establish the patency of the aqueduct. The reliability of different diagnostic methods is discussed and the value of metrizamide computed tomographic ventriculography is emphasized. Unsatisfactory results following membrane excision in early cases, and observations of CSF dynamic disturbances confirm the futility of the direct approach for the management of the Dandy-Walker syndrome. The aqueduct was invariably patent and allowed either primary cyst or ventricular shunting, although simultaneous double shunting using a 'Y' connector may need to be carried out later. The mortality rate for the series was 18%. At follow-up 54.5% of the children were judged to have normal IQs.

In the period 1976-1987, the number of intracranial arachnoid cysts treated at our institute was 60: sylvian, 29; midline supratentorial, 13; subtentorial, 18. The diagnosis was mainly made by means of the results of a combination of CT, dynamic cisternography, and ventriculography. Based on an analysis of the preoperative investigations and operative results, an attempt was made to determine the appropriate treatment more precisely in cysts at different locations. The direct microsurgical approach with membrane excision was mainly used in combination with a preliminary VA shunt to treat hydrocephalus. The direct approach was supplemented with secondary cavity shunting in 5 cases. In more than half of the patients we used membrane excision alone (mainly children with sylvian cysts). In suprasellar cysts we consider the subfrontal approach to be more appropriate than the transventricular one. We restricted the use of primary cyst shunting as an alternative treatment to only 3 infants, with huge cysts. The follow-up reveals that 82.7% of the cases were favorable affected to varying degrees.

A retrospective study was performed in 100 children, who were operated on between 1954 and 1984 for cerebellar astrocytoma. Twenty-nine patients died during the 1st month after the operation. Of the patients who survived, 24 lived up to 5 years, 17 up to 10 years, and 30 lived 20 or more years. In 22 cases, tumor recurrence was the reason for reoperation. Radiation therapy was used in 25 cases with histological malignancy and/or after partial removal of the tumor. The analysis in 6 cases with brainstem involvement allowed us to conclude that in such cases the prognosis is poor with regard to survival. Although total removal of cerebral astrocytomas appears to be the most effective form of treatment, we are of the opinion that even subtotal excision may be compatible with long-term survival. This suggests that many of these tumors may show benign biological behavior.

During a 20-year period (1964-1983), the authors managed 60 children with intracranial ependymomas. In 37 patients the tumors were located in the posterior cranial fossa, and in the remaining 23 they were supratentorial. The histological examination in 26 children revealed ependymoblastomas. The average duration of the clinical evolution was 4 months and 5 days in the supratentorial neoplasms and 3 months and 6 days in the subtentorial. Besides the intracranial hypertension, present in about 80% of the patients, specific localizing signs were seen in 70% of the children with subtentorial and in 40% of those with supratentorial tumors. Because of the growth pattern in posterior fossa ependymomas and despite the prevalence of histologically benign neoplasms, radical resection was accomplished in only 21.6% of the cases, as compared with 30.4% in supratentorial tumors. The postoperative mortality remains high: 29.7% in subtentorial tumors and 17.4% in supratentorial. The 1-year survival rate in subtentorial neoplasms was 70.3%, the 3-year survival 29.7%, and the 5-year survival 16.2%. The corresponding figures for supratentorial ependymomas more favorable: 82.6%, 43.5%, and 26.1%, respectively. The most important factors for improving the outcome at the present time appear to be as radical a resection as possible, supplemented with postoperative radiotherapy and chemotherapy.