Isolated third and fourth ventricles associated with neurosarcoidosis successfully treated by neuroendoscopy--case report.

A 48-year-old woman presented with a unique case of isolated third and fourth ventricles associated with neurosarcoidosis, manifesting as upward gaze palsy. She had a past history of surgery for intracranial sarcoid granuloma 10 years previously and placement of a ventriculoperitoneal shunt 3 years later. Magnetic resonance imaging revealed isolated third and fourth ventricles. Endoscopic plasty of the right foramen of Monro, fenestration of the septum pellucidum, and revision of the ventriculoperitoneal shunt were performed. Postoperatively the size of the third and fourth ventricles was reduced, and the upward gaze palsy resolved. Endoscopic treatment is less invasive and effective for the treatment of multiple septum formation in the ventricular system.