Membranous obstruction of the fourth ventricle outlet. A case report.

We report the case of a 15-year-old girl with amenorrhea and a several-week history of headache. After the diagnosis of membranous obstruction of the foramen of Magendie suggested by MRI, suboccipital craniotomy for removal of the membrane was carried out. The patient made an excellent postoperative recovery, and postoperative phase-contrast MRI demonstrated patent cerebrospinal fluid (CSF) pathways at the level of the foramina of Magendie and Luschka. We believe that this case is of interest because of the unequivocal evidence on MRI studies of the occlusion of the foramen of Magendie preoperatively, and because of the dramatic postoperative MRI findings demonstrating the effectiveness of the surgical procedure both in terms of ventricular size and CSF flow characterization. Copyright 2001 S. Karger AG, Basel