Unilateral hydrocephalus due to idiopathic anomaly of foramen of Monro, treated successfully with endoscopic technique. Report of three cases

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.

Prenatal diagnosis and postnatal management of congenital unilateral hydrocephalus for stenosis of the foramen of Monro

Congenital hydrocephalus and ventriculomegaly can be diagnosed reliably with prenatal ultrasound and Magnetic Resonance Imaging (MRI). Unilateral hydrocephalus is uncommon, and the prognosis depends on etiology and postnatal management. Here, we present a case of a 32-years-old woman with prenatal diagnosis of unilateral hydrocephalus associated with stenosis of the foramen of Monro. Unilateral hydrocephalus is an uncommon feature that can be detected prenatally on ultrasound and MRI. In case of isolated stenosis of the foramen of Monro prognosis is good.

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

INTRODUCTION

A wide spectrum of etiologies can obstruct foramen of Monro (FOM) and result in hydrocephalus. Congenital occlusion of FOM is a rare entity which may present either in childhood or in adulthood.

METHODS

Between 2007 and 2016, we screened all pediatric patients with hydrocephalus of either one or both lateral ventricles. Congenital occlusion of FOM was confirmed in the absence of masses occupying the FOM, prenatal or postnatal central nervous system (CNS) infections, intraventricular hemorrhage, previous cerebral intervention, or associated CNS anomalies affecting the flow of cerebrospinal fluid (CSF). We have performed a comprehensive literature review of the previously reported cases and provided a tentative embryological pathogenesis of FOM occlusion.

RESULTS

We introduce 10 new cases of congenital FOM obstruction. The mean age of the patients was 6.65 ± 10.51 months. Two patients underwent ventriculo-peritoneal (VP) shunting as the primary intervention, while endoscopic septostomy was performed in the others. The mean follow-up was 3.05 ± 2.16 years (1-8 years). Although the hydrocephalus was controlled, all patients remained hemiparetic with some degree of developmental and cognitive impairments. Previously, 38 similar cases were reported: 10 of them (26.3%) were adults. Overall, VP shunting was the treatment of choice in 44.7% of patients. While most adults fully recovered, 7.2% of pediatrics remained hemiparetic and 10.7% of them had cognitive and developmental delay.

CONCLUSION

Ten cases of congenital obstruction of the foramen of Monro have been managed through a period of 9-year study. Details of these patients in addition to 38 previously reported cases are presented in this study.

Hydrocephalus caused by unilateral foramen of Monro obstruction: A review on terminology

Background:

Hydrocephalus caused by unilateral foramen of Monro (FM) obstruction has been referred to in literature by many different terminologies. Precise terminology describing hydrocephalus confined to just one lateral ventricle has a very important prognostic value and determines whether or not the patient can be shunt free after an endoscopic procedure.

Methods:

Aiming to define the best term for unilateral FM obstruction, 19 terms were employed on PubMed database (http://www.ncbi.nlm.nih.gov/pubmed) as quoted phrases.

Results:

A total of 194 articles were found. Four patterns of hydrocephalus were discriminated as a result of our research term query and were divided by types for didactic purpose. Type A - partial dilation of the lateral ventricle; Type B - pure unilateral obstruction of the FM; Type C - previously shunted patients with secondary obstruction of the FM; and Type D - asymmetric lateral ventricles with patent FM.

Conclusion:

In unilateral FM obstruction hydrocephalus, an in-depth review on terminology application is critical to avoid mistakes that may compromise comparisons among different series. This terminology review suggests that Type B hydrocephalus, i.e., the hydrocephalus confined to just one lateral ventricle with no other sites of cerebrospinal fluid circulation blockage, are best described by the terms unilateral hydrocephalus (UH) and monoventricular hydrocephalus, the first being by far the most popular. Type A hydrocephalus is best represented in the literature by the terms uniloculated hydrocephalus and loculated ventricle; Type C hydrocephalus by the terms isolated lateral ventricle and isolated UH; and Type D hydrocephalus by the term asymmetric hydrocephalus.