Congenital obstruction of foramen of Monro: report of 10 patients and literature review

Case Report: Occlusion of the foramen of Monro treated with endoscopic septostomy and foraminotomy in a preterm neonate

Background

Hydrocephalus is a brain abnormality frequently encountered in neonates. There are several known etiologies of hydrocephalus, which can be classified as either congenital or acquired. Occlusion of the foramen of Monro (FOM) is a cause of hydrocephalus and can be either congenital or secondary to various disorders. Idiopathic obstruction of the FOM presenting as prenatal ventriculomegaly is extremely rare but has been reported.

Case presentation

We present the case of a preterm newborn with severe bilateral hydrocephalus due to FOM occlusion in the prenatal period. Although the neonate had normal head circumference and no clinical symptoms after birth, brain sonography revealed progressive ventriculomegaly. Further image revealed bilateral ventriculomegaly with normal-sized third and fourth ventricles. We suspected a complete obstruction of the right and a partial obstruction of the left of the FOM. The neonate underwent endoscopic septostomy and foraminotomy, resulting in improvement.

Conclusion

We report a case of preterm FOM occlusion in the youngest and smallest neonate to date. Endoscopic septostomy and foraminotomy were performed in order to avoid ventriculoperitoneal shunt-related complications, highlighting the viability of endoscopic procedures which should be the primary treatment in preterm neonates with FOM occlusion.

Idiopathic membranous occlusion of the foramen of Monro: an unusual cause of hydrocephalus and headache in adults

Occlusion of foramen of Monro is an uncommon clinical entity that usually presents in children. Common causes are obstructing mass, infectious etiologies or vascular malformation. Rarely, it may be an idiopathic stricture or membrane. We report a case of idiopathic membranous obstruction of the foramen of Monro in a 45-year-old male with no past medical or surgical history. He presented with new intermittent dull and burning bifrontal severe headache for 2 d, which was alleviated slightly by non-steroidal anti-inflammatory medication. Imaging showed marked dilation of the lateral ventricles with normal third and fourth ventricles. The patient was discharged initially with conservative medical management and close follows up; however, the headache continued to progress and neurosurgical intervention was offered. The patient underwent endoscopic exploration, fenestration of the septum pellucidum, and right ventriculoperitoneal shunt placement. Bilateral membranous obstruction of foramina of Monro and an auto-fenestrated cavum septum pellucidum were identified intraoperatively. The patient reported resolution of headache post-operatively without recurrence on 1-month follow up. This case is unusual in that the patient presented without any known neurologic history or prior intracranial infections. It became apparent at the time of surgery that chronic obstruction of the bilateral foramina with collapse of the third ventricle had developed, and the safest durable treatment for him was septostomy and cerebrospinal fluid (CSF) shunt placement.