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

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.

Septostomy and Monroplasty in Isolated Lateral Ventricle After Removal of a Third Ventricle Colloid Cyst: 2-Dimensional Operative Video

Isolated unilateral hydrocephalus (IUH) is a condition caused by unilateral obstruction of the foramen of Monro.1 Etiopathogenic causes include tumors, congenital lesions, infective ventriculitis, intraventricular haemorrhage, and iatrogenic causes such as the presence of contralateral shunts.2,3 Neuroendoscopic management is considered the "gold-standard" treatment in IUH.4 Even if endoscopic septostomy and foraminoplasty in IUH are well-known procedures,5,6 IUH after an interhemispheric transcallosal transchoroidal approach for removal of a III ventricle colloid cyst is a complication barely described in literature. Video 1 describes this rare complication and the neuroendoscopic treatment adopted, including the operative room setup, patient's positioning, instrumentation needed, and a series of intraoperative tips for the performance of septostomy and Monroplasty via a single, precoronal burr hole. The scalp entry point and endoscope trajectory, homolateral to the dilated ventricle, were planned on the neuronavigation system. The avascular septal zone away from the septal veins and body of the fornix was reached, and the ostomy was performed. At the end of the procedure, Monroplasty was performed, too. The procedure was effective in solving the hydrocephalus and patient's clinical picture. No surgical complications occurred. Imaging demonstrated an evident and progressive reduction of enlarged lateral ventricle. In authors' opinion, the single burr-hole approach, ipsilateral to the enlarged ventricle, provides an optimal identification the intraventricular anatomy and allows Monroplasty to be performed, if deemed feasible during surgery. The patient consented to the procedure. The participants and any identifiable individuals consented to publication of their images.

Neurococcidiomycosis in children with hydrocephalus: assessment of functional outcome, quality of life and survival in relation to neuroimaging findings

PURPOSE

Coccidioidal meningitis (CM) is an uncommon disease frequently misdiagnosed. Neuroimaging and mortality are not considered in detail in previous pediatric CM series. Our objective is to evaluate outcome of pediatric neurococcidiomycosis in relation to neuroimaging findings.

METHODS

We performed a prospective, observational, cross-sectional study in children with hydrocephalus and CM treated at Specialties Hospital in Torreon, Mexico (between 2015 and 2020). The outcome was evaluated by Hydrocephalus Outcome Questionnaire (HOQ) and the modified Rankin Scale (mRS). Follow-up was established at the first shunt surgery and survival since CM diagnosis confirmation. Neuroimaging was analyzed in relation to clinical data, outcome and survival. Kaplan-Meier analysis was performed with IBM-SPSS-25.

RESULTS

Ten pediatric cases with CM and hydrocephalus were reported. Aged 6-228 months, 60% were female. Mean number of surgeries was 4.3 SD ± 3 (range 1-15). Asymmetric hydrocephalus was the most common neuroimaging finding (70%), followed by cerebral vasculitis (20%) and isolated fourth ventricle (IFV) (20%). The mean HOQ overall score was 0.338 SD ± 0.35. A minimum follow-up of 18 months was reported. Mean survival was 13.9 SD ± 6.15 months (range 3-24). Poor survival was correlated with asymmetric hydrocephalus (p = 0.335), cerebral vasculitis (p = 0.176), IFV (p < 0.001), bacterial superinfection (p = 0.017), lower mRS scores at hospital discharge (p = 0.017) and during follow-up (p = 0.004). The mortality rate was 20%.

CONCLUSIONS

We report the largest series in Latin America of pediatric CM and hydrocephalus. Asymmetric hydrocephalus, IFV and cerebral vasculitis are complications that increase mortality and must be early diagnosed for a timely surgical and medical treatment. HOQ and mRS could be alternative scales to evaluate outcome in these patients. After a long follow-up (18 months), survival remained poor after diagnosis confirmation in our series.

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.

Neuroendoscopic fenestration of the septum pellucidum for monoventricular hydrocephalus

OBJECTIVES

Monoventricular hydrocephalus (MH) is a rare condition in which the site of obstruction is located around one of the interventricular foramen. In this paper, the authors offer their experiences in the neuroendoscopic management of this uncommon type of hydrocephalus.

PATIENTS AND METHODS

The authors retrospectively reviewed 12 neuroendoscopic procedures performed between July 2003 and June 2011 with MH. Clinical and radiological charts were reviewed and analysed.

RESULTS

The operative course is a simple and successful procedure, and the postoperative complaints are mild. The postoperative radiological findings showed maintenance of ventricular enlargement in four cases and a significant decrease in enlargement in eight patients. However, upon shifting of the septum pellucidum, the periventricular transudation disappeared in all patients.

CONCLUSIONS

Fenestration of the septum pellucidum by neuroendoscope is the best treatment for patients with monoventricular hydrocephalus. The approach for fenestration of the septum pellucidum is based on the experience of the neurosurgeon and the preoperative planning.

Idiopathic bilateral stenosis of the foramina of Monro treated using endoscopic foraminoplasty and septostomy

Hydrocephalus caused by stenosis of the foramen of Monro is rare. The authors describe a 28-year-old female patient with bilateral foraminal stenosis treated using endoscopic septostomy and unilateral foraminal balloon plasty (foraminoplasty). The patient's hydrocephalus and symptoms resolved postoperatively. Endoscopic strategies may be employed as first-line therapy in this condition.

Neuroendoscopic fenestration of the foramen of Monro without septostomy for unilateral hydrocephalus following neonatal intraventricular hemorrhage

PURPOSE

Unilateral hydrocephalus is a rare type of hydrocephalus caused by germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) in preterm infants. We present a case of posthemorrhagic unilateral hydrocephalus in a preterm infant that was successfully treated with neuroendoscopic fenestration of the foramen of Monro without septostomy.

CASE REPORT

Brain ultrasound of a female infant born at 26(+1) weeks gestation revealed delayed unilateral hydrocephalus in the frontal horn of the lateral ventricle after IVH. In this case, unilateral hydrocephalus appeared to be caused by chronic inflammatory changes, leading to membrane formation in the foramen of Monro. After neuroendoscopic foraminoplasty without septostomy, ventricular size decreased, and the patient's neurological status improved per the PREMIE-NEURO exam, a neurologic examination for preterm infants of gestational age 23-37 weeks.

CONCLUSIONS

This case demonstrates that simple repermeation of the foramen without fenestration of the septum pellucidum can successfully treat membrane-induced unilateral hydrocephalus. Also, because hydrocephalus can develop even after stabilization of GMH-IVH, close follow-up during the first year of life and beyond may reduce the likelihood of brain damage due to advanced hydrocephalus.

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 Septostomy for Isolated Lateral Ventricle

The clinical features and endoscopic findings were investigated in 20 patients with isolated lateral ventricle treated by neuroendoscopic septostomy to establish cerebrospinal fluid communication and open an isolated ventricular compartment. The endoscopic procedure was incomplete because of thickened septum pellucidum and insufficient working space in two adults with postmeningitic hydrocephalus. Two children underwent second septostomy. In all other cases, results were good and there were no complications related to endoscopic procedures. Endoscopic septostomy is less invasive and has few complications. Intraoperative navigation and the biportal approach may be required in difficult cases with multiple septum formation and severe postmeningitic hydrocephalus. Adequate stomal size is required in high-risk groups including children under 2 years of age.

[Endoscopic fenestration as a treatment for asymmetrical hydrocephalus due to obstruction of the foramen of Monro]

Unilateral dilatation of the lateral ventricle is a rare condition. The most common causes are tumors of the lateral ventricles or in the area of the third ventricle, acute or chronic inflammatory gliosis, cysticercosis or congenital atresia of the foramen of Monro. We report a case of asymmetrical dilatation of the lateral ventricle in an adult patient presenting with a raised intracranial pressure syndrome caused by narrowing of the foramen of Monro which was occluded by a thin membrane. The patient underwent successful endoscopic fenestration of the Foramen of Monro.

Unreported anatomical variation of septum pellucidum

During gross anatomy dissections of the brain, a developmental abnormality of the septum pellucidum was found in a 31-year-old male cadaver. Other parts of the central nervous system in this cadaver were normal in every aspect. Histological samples were taken from the neighboring areas of this abnormality, and they were examined under light microscope and scanning electron microscope. In this abnormality of the septum pellucidum, the two laminae of the septum pellucidum were fused together and there was a hole located 1 cm anterior to its apex. The maximum diameter of the hole was 0.5 cm in the sagittal plane and 0.6 cm in the vertical plane. In the light microscopic and scanning electron microscopic examinations, the free margin of this foramen was regular, and the surrounding tissue was intact and histologically unique to the septum pellucidum. Ependymal cells were present at the free margin of the foramen. Cavum vergae, cavum septum pellucidum, and agenesis of the septum pellucidum are described in the literature. These three abnormalities are seen in cadavers usually with histories of schizophrenia and other psychiatric or neurologic disorders. In a retrospective study, the cadaver with this abnormality had a history of schizophrenia and no history or signs of any kind of brain or head operation. As far as we could ascertain, the abnormality described here has not been reported previously.

Nonprogressive congenital unilateral ventriculomegaly

Congenital unilateral ventriculomegaly is a rare condition, usually caused by obstruction of the foramen of Monro. In the past, this condition required surgical intervention. We present a female newborn with nonprogressive unilateral ventriculomegaly which was initially detected by prenatal sonography. No surgical intervention was performed, and during the 9 months of follow-up, she had normal head growth and reached appropriate developmental milestones.