Child s Nervous System | 2019
Suprapineal ventricular diverticula secondary to hydrocephalus shunt malfunction
Abstract
Dear Editor: A 15-year-old girl presented to the emergency room with a 4-week history of progressive headache and blurred vision. She was operated on in another institution 4 years previously for a cerebellar medulloblastoma (suboccipital tumor resection) with supratentorial hydrocephalus (permanent ventriculoperitoneal shunt placement). On physical examination, she was consciousness, afebrile, and had papilledema on the fundoscopic exam with severe upgaze palsy. The shunt reservoir could not be depressed percutaneously. Cranial m ag n e t i c r e s o n a n c e im a g i n g (MR I ) s h owe d triventricular hydrocephalus with suprapineal cyst in connection with the posterior border of the third ventricle causing midbrain tegmental compression (Fig. 1a– c). She had no evidence of spinal metastasis on spinal MRI. At this stage, the preoperative diagnosis was an obstructive hydrocephalus by shunt malfunction. She underwent intraventricular shunt revision following which she was relieved immediately of all her symptoms. Follow-up imaging at 1 month revealed resolution of most abnormalities especially a complete disappearance of the suprapineal cyst (Fig. 1d–f). Therefore, the final diagnosis of this cystic lesion was a secondary third ventricular diverticulum. At the most recent 2-year follow-up, the patient remains well. A MRI of the head was performed to confirm that the ventricular size remained stable. Ventricular diverticula is an unusual cystic subpial collection of cerebrospinal fluid resulting from rupture of the ependymal lining of the ventricular system in cases of severe, long-standing hydrocephalus [1, 2]. The third ventricle represents the point of origin of about one-third of ventricular diverticula [1]. The weakest areas of the third ventricle are the infundibular, the lamina terminalis, and suprapineal recesses. An expansion diverticulum of the suprapineal recess usually causes a midbrain compression with most severe deformation of the periaqueductal region and subsequent ocular signs (especially the typical Parinaud syndrome as seen in our case) [3]. Because of their rarity, ventricular diverticula could be overlooked or misdiagnosed as other cystic lesions (especially growth tumor) [2]. The typical treatment is ventriculoperitoneal shunting, and it is not necessary to remove ventricular diverticula itself [4]. For Osuka et al., endoscopic observation of the cyst may be very useful for accurate diagnosis and safe treatment [5].