Adult “congenital” bilateral occlusion of the foramina of monro

Bilateral occlusion of the foramina of Monro was detected and treated in a hydrocephalic adult who developed rapid striking recent memory loss. She was treated by midline windowing of the third ventricle into the dilated lateral ventricles at a location 2 cm posterior to the occluded foramina of Monro. No inflammation was present. A biopsy specimen showed no evidence of malignancy. A reservoir was placed for long-term measurement of intraventricular pressure. Ten-year follow-up with pressure measurements, serial computed tomography scans, and magnetic resonance imaging showed no evidence of tumor.