[Cystic abnormalities of the brain: stereotaxic diagnosis and therapy]

We present the stereotactic treatment and evaluation of 33 patients with congenital cysts of the brain (6 cavum septi pellucidi/cavum vergae cysts, 5 suprasellar cysts, 3 intraventricular cysts, 4 cysts of the interhemispheric fissure, 4 cysts of the cerebral convexity, 5 supracollicular cysts, 3 cysts in the cisterna ambiens, 2 temporomedial cysts and 1 cyst in the pontomesencephalic junction). The patients were seen during an 8-year period (1984-1992) and had a mean follow-up time of 27 months. In 23 patients with cysts in or near the cerebral midline or at the cerebral convexity, a stereotactic ventriculocystostomy resulted in clinical improvement with diminished cyst size. Another 8 patients with relatively small cysts profited from stereotactic aspiration of the cyst contents. Three complications (bleeding, aseptic meningitis, catheter infection) remained without sequelae. The stereotactic procedure is the treatment of choice for these lesions because of the low operative risk, its minimal invasiveness and the possibility of distinguishing primary congenital cysts from other pseudocystic lesions. In well-chosen cases the carefully planned stereotactic internal derivation of the cysts in the ventricular system led to a long-lasting beneficial effect. Open craniotomy or shunting procedures can be avoided for most cases of congenital intracranial cysts.