Congenital constriction of the foramen of Monro

Adult idiopathic bilateral occlusion of foramen of Monro: Systematic review with illustrative case

BACKGROUND

Adult idiopathic occlusion of foramen of Monro (AIOFM) is a rare condition that results in hydrocephalus, and bilateral presentation is even rarer. Here we report a case of idiopathic bilateral stenosis of the foramen of Monro in an adult patient and performed a systematic literature review on the current treatment options and outcomes.

METHODS

We performed a systematic review of SCOPUS, Science Direct, and PubMed databases in accordance with PRISMA guidelines. Data on demographics, clinical presentation, imaging findings, type of AIOFM, treatment, and outcomes were collected.

RESULTS

A total of 22 cases of bilateral AIOFM were identified in the literature, including ours. The median age was 38.5 years (range: 20-53), with no sex predilection. The most common presenting symptoms were headache (n=16, 73%) and vomiting (n=10, 45%). There were 9 cases of Type 1 AIOFM (stenosis) and 13 cases of Type 2 (membrane occlusion). Majority of patients underwent surgical treatment, mostly endoscopic unilateral foraminoplasty and septostomy (59%), followed by ventriculoperitoneal shunt insertion (31%). One patient underwent medical management only to alleviate her presenting symptoms (seizures). The overall outcome was good for majority of patients at a median follow-up of 6 months.

CONCLUSION

Bilateral AIOFM is a rare condition that may easily be missed, so neurosurgeons should be cognizant of this disease entity. Identification of the type of AIOFM may guide surgical decision-making. Treatment options include neuroendoscopic procedures such as septostomy and foraminoplasty, and ventriculoperitoneal shunt insertion.

Late-onset occlusion of the Monro foramina after endoscopic third ventriculostomy in adults: Case discussion and review of the literature

Background:

Few cases of adult idiopathic occlusion of the foramen of Monro (AIOFM) are described in the literature. The diagnosis of AIOFM after an endoscopic procedure is even more infrequent.

Case Description:

We described the case of a 50-year-old woman who developed bilateral membranous occlusion of both Monro foramina 20 years after an endoscopic third ventriculostomy (ETV) for triventricular hydrocephalus due to an aqueductal stenosis. The patient underwent an endoscopic treatment (left foraminoplasty and septostomy) to check the patency of the stoma on the floor of the third ventricle. After the endoscopic procedure, the symptoms improved and the postoperative magnetic resonance imaging (MRI) demonstrated the resolution of the biventricular hydrocephalus.

Conclusion:

Bilateral occlusion of both FM with consequent bilateral lateral ventricles enlargement is an extremely rare condition, especially if we consider the cases of biventricular hydrocephalus after endoscopic procedures. In our opinion, an endoscopic approach should be attempted as first choice procedure, avoiding any intraventricular stent or shunt placement.

Neuroendoscopic Management of Coexisting Congenital Agenesis of Bilateral Foramen of Monro with Aqueductal Stenosis and Chiari Malformation: Case Report and Review of the Literature

BACKGROUND

Bilateral occlusion of the foramen of Monro with aqueductal stenosis is a rare entity. Only 1 previous case has been reported in the literature.

CASE DESCRIPTION

We present a 25-year-old female who presented with chronic headache of 7 years duration. Neurologic examination revealed only papilledema. Imaging showed symmetrical dilation of both lateral ventricles with mild dilation of the third ventricle and a normal fourth ventricle, suggesting occlusion of both foramina of Monro with membranous web formation in the upper part of the aqueduct. There was tonsillar herniation without syrinx. She underwent neuroendoscopic foraminoplasty, septostomy, and third ventriculostomy. The patient experienced total relief of headache and showed reduced volume of both lateral ventricles at follow-up.

CONCLUSIONS

Bilateral occlusion of foramen of Monro with aqueductal stenosis and tonsillar herniation is rare cause of obstructive hydrocephalus, and can be managed effectively with neuroendoscopic procedure.

Endoscopic Strategy in Surgical Treatment of Adult Idiopathic Bilateral Occlusion of the Foramen of Monro and Review of the Literature

BACKGROUND

Endoscopic approach has been used increasingly for the surgical treatment of adult idiopathic bilateral occlusion of the foramen of Monro (AIOFM). The aim of this study is to assess and compare the results of this strategy with other surgical methods of treating AIOFM.

METHODS

A retrospective study was performed to identify patients with AIOFM treated in our department from 2012 to 2017. We also performed a search of the literature to detect any case of AIOFM reported from 1980 to 2017 to provide a comprehensive assessment of the treatment of this condition. AIOFM was classified as 4 groups, including bilateral true stenosis of the foramen of Monro (FM), bilateral membrane occlusion of the FM, unilateral true FM stenosis with septum deviation, and unilateral membrane occlusion of the FM with septum deviation all assessed and discussed separately.

RESULTS

We found four patients with AIOFM surgically treated with endoscopic procedures in our department between the years of 2012 to 2017 with an excellent outcome. Fourteen studies were also detected during our review of the literature, most of which involved treatment with neuroendoscopy and excellent outcomes. We found that neuroendoscopy could be the first-line strategy to treat all 4 types of AIOFM.

CONCLUSIONS

Endoscopic strategy is associated with excellent outcomes and fewer risks in treatment of all types of AIOFM; it is also less invasive compared with ventriculoperitoneal shunt insertion.

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.

Enlarged thalamostriate vein causing unilateral Monro foramen obstruction. Case report

Causes of unilateral hydrocephalus resulting from an obstruction at the Monro foramen include foraminal atresia, tumors, gliosis, contralateral shunting, and infectious and inflammatory conditions. However, few reports in the literature cite vascular lesions as the cause of the obstruction. To their knowledge, the authors present the first report of unilateral hydrocephalus occurring due to an abnormally enlarged thalamostriate vein independent of an arteriovenous malformation or developmental venous angioma. The condition was treated successfully by endoscopic septum pellucidum fenestration. A 28-year-old man was referred for evaluation due to a 10-year history of chronic headaches that worsened in severity over the past year. A CT scan of the head revealed unilateral right ventricular dilation. Cranial MR imaging with and without contrast administration showed a dilated right thalamostriate-internal vein complex without any evidence of associated arteriovenous malformation or venous angioma. Endoscopic exploration of the right lateral ventricle showed an enlarged subependymal thalamostriate vein obstructing the Monro foramen. An endoscopic fenestration of the septum pellucidum was performed, resulting in alleviation of the patient's symptoms. Abnormally enlarged venous structures may cause obstructive unilateral hydrocephalus and can be a rare cause of chronic, intermittent headaches in adults. Endoscopic fenestration of the septum pellucidum is an effective treatment.

Neuroendoscopic treatment of idiopathic occlusion of the foramen of Monro in adults--two case reports

Two adults presented with hydrocephalus due to idiopathic obstruction of the bilateral foramina of Monro, manifesting as clinical signs of chronically elevated intracranial pressure. No inflammation was present. The primary surgical treatment was neuroendoscopic reconstruction of the right foramen of Monro. A 37-year-old man had a spontaneous perforation of the septum pellucidum. The patient required a ventriculoperitoneal shunt, although postoperative ventriculography proved free passage of cerebrospinal fluid from the lateral ventricle into the third ventricle. A 62-year-old man underwent additional septostomy and third ventriculostomy, and the neuroendoscopic intervention relieved the presenting symptoms without additional treatment. The biopsy specimens showed no evidence of malignancy in either case. Neuroendoscopic intervention is an alternative treatment in the management of hydrocephalus due to idiopathic obstruction of the foramen of Monor. The procedure is less invasive than open microsurgical reconstruction and can even avoid ventriculoperitoneal or ventriculoatrial shunting.

Neuroendoscopic procedures: anesthetic considerations for a growing trend: a review

The recent trend in neurosurgery is shifting toward further reduction in invasiveness to minimize trauma to the brain. Endoscopy holds the promise of shortened hospital stay with improved postoperative outcome. An important minimally invasive technique is neuroendoscopy. The ventricular system and subarachnoid space of the brain provide suitable conditions for the use of an endoscope. The currently available literature focuses only on recent advances in neuroendoscopy from the surgical perspective. To date, there is paucity of anesthetic literature emphasizing the implications for this growing trend. The surgical technique, instrumentation, anesthetic requirements, potential pitfalls and complications of this technique must be completely understood to ensure a successful outcome. The purpose of this review is to provide knowledge of indications, instrumentation, and anesthetic considerations in anticipation of complications steming from this procedure.

Unilateral hydrocephalus resulting from occlusion of foramen of Monro: a new procedure in the treatment: stereotactic fenestration of the septum pellucidum

Obstruction at the foramen of Monro resulting in unilateral hydrocephalus is an uncommon entity that may be caused by a wide range of lesions including tumors, vascular malformations, and inflammatory conditions. A case of unilateral hydrocephalus secondary to congenital atresia of the foramen of Monro treated with stereotactic fenestration of the septum pellucidum is presented.

Adult "congenital" bilateral occlusion of the foramina of Monro

Bilateral occlusion of the foramina of Monro was detected and treated in a hydrocephalic adult who developed rapid striking recent memory loss. She was treated by midline windowing of the third ventricle into the dilated lateral ventricles at a location 2 cm posterior to the occluded foramina of Monro. No inflammation was present. A biopsy specimen showed no evidence of malignancy. A reservoir was placed for long-term measurement of intraventricular pressure. Ten-year follow-up with pressure measurements, serial computed tomography scans, and magnetic resonance imaging showed no evidence of tumor.