Slit Ventricle as a Neurosurgical Emergency: Case Report and Review of Literature

Superb microvascular ultrasound is a promising non-invasive diagnostic tool to assess a ventriculoperitoneal shunt system function: a feasibility study

The objective of this pilot study was to assess the reliability of superb microvascular ultrasound (SMI) for the measurement of the cerebrospinal fluid (CSF) flow within VPS systems as an indirect sign for shunt dysfunction. Asymptomatic hydrocephalus patients, with a VPS system implanted between 2017 and 2021, were prospectively enrolled in the study. Using SMI, the CSF flow within the proximal and distal catheters were analysed. Before and after pumping the shunt reservoir, intraabdominal free fluid, optical nerve sheath diameter (ONSD), and papilla diameter (PD) were evaluated and correlated with the amount of valve activation. Nineteen patients were included. A flow was detectable in 100% (N = 19) patients in the proximal and in 89.5% (N = 17) in the distal catheter. The distal catheter tip was detectable in 27.7% (N = 5) patients. Free intraabdominal fluid was initially detected in 21.4% (N = 4) patients and in 57.9% (N = 11) at the end of the examination (P = 0.049). ONSD was significantly lower after pump activation (4.4 ± 0.9 mm versus 4.1 ± 0.8 mm, P = 0.049). Both peak velocity and flow volume per second were higher in proximal compared to distal catheters (32.2 ± 45.2 versus 5.6 ± 3.7 cm/sec, P = 0.015; 16.6 ± 9.5 ml/sec versus 5.1 ± 4.0 ml/sec, P = 0.001, respectively). No correlation was found between the number of pump activations and the changes in ONSD (P = 0.975) or PD (P = 0.820). SMI appears to be a very promising non-invasive diagnostic tool to assess CSF flow within the VPS systems and therefore affirm their function. Furthermore, appearance of free intraperitoneal fluid followed by repeated compression of a shunt reservoir indicates an intact functioning shunt system.

Rare Complications of CSF Diversion: Paradoxical Neuroimaging Findings in a Double, Chiasmic Case Report

Two patients with CSF shunting systems exhibited symptoms of altered intracranial pressure. Initial neuroimaging led to misinterpretation, but integrating clinical history and follow-up imaging revealed the true diagnosis. In the first case, reduced ventricular size was mistaken for CSF overdrainage, while the actual problem was increased intracranial pressure, as seen in slit ventricle syndrome. In the second case, symptoms attributed to intracranial hypertension were due to CSF overdrainage causing tonsillar displacement and hydrocephalus. Adjusting the spinoperitoneal shunt pressure resolved symptoms and imaging abnormalities. These cases highlight the necessity of correlating clinical presentation with a deep understanding of CSF dynamics in shunt assessments.

Visual acuity loss and sixth nerve palsy as the only manifestations of slit ventricle syndrome

The case is presented of a girl diagnosed with obstructive hydrocephalus due to pilomyxoid astrocytoma, which required a ventriculoperitoneal shunt (VPS) at the age of 5 years and 10 months. Two months later, magnetic resonance imaging of the brain did not show ventriculomegaly or other signs of increased intracranial pressure. At the age of 6 years and 2 months, a rapid onset of bilateral visual acuity loss developed and she was diagnosed with slit ventricle syndrome. Despite valve revisions of the VPS, she developed an abrupt decline of visual acuity to hand motion at 10 cm. Fundus examination revealed bilateral optic atrophy. She did not report any other systemic symptoms suggesting increased intracranial pressure, such as headache, nausea, vomiting, lethargy, irritability, or altered levels of consciousness.

Slit ventricle syndrome: Historical considerations, diagnosis, pathophysiology, and treatment review

After the introduction of shunt treatment for the management of childhood hydrocephalus, a wide variety of complications related to this treatment modality have been recognized. The entity of slit ventricle syndrome (alternatively, symptomatic ventricular coaptation) is one of them, is frequently encountered in the pediatric population and its symptom complex resembles that of shunt failure. We conducted research on PubMed^®, MEDLINE^®, and Web of Science^®, using the keywords: “slit ventricles,” “slit ventricle syndrome,” “SVS” and “ventricular coaptation.” The aim of our review was to trace the advances made through the past decades, concerning our knowledge about the clinical characteristics, pathophysiology, and treatment options of this entity. The discrepancy among researchers about the offending etiology and the optimum treatment algorithm of this entity, as well as the necessity of an updated concept regarding shunt over drainage is analyzed. The multiple treatment modalities proposed and pathophysiologic mechanisms implicated for the treatment of slit ventricle syndrome illustrate the complexity of this entity. Consequently, the issue requires more detailed evaluation. In this review, we comment on all the main facets related to shunt over drainage and the resultant slit ventricle syndrome.

Shunt Overdrainage: Reappraisal of the Syndrome and Proposal for an Integrative Model

Although shunt overdrainage is a well-known complication in hydrocephalus management, the problem has been underestimated. Current literature suggests that the topic requires more examination. An insight into this condition is limited by a lack of universally agreed-upon diagnostic criteria, heterogeneity of published series, the multitude of different management options and misunderstanding of relationships among pathophysiological mechanisms involved. We carried out a review of the literature on clinical, radiological, intracranial pressure (ICP), pathophysiological and treatment concepts to finally propose an integrative model. Active prophylaxis and management are proposed according to this model based on determination of pathophysiological mechanisms and predisposing factors behind each individual case. As pathophysiology is progressively multifactorial, prevention of siphoning with gravitational valves or antisiphon devices is mandatory to avoid or minimize further complications. Shunt optimization or transferal and neuroendoscopy may be recommended when ventricular collapse and cerebrospinal fluid isolation appear. Cranial expansion may be useful in congenital or acquired craniocerebral disproportion and shunting the subarachnoid space in communicating venous hydrocephalus and idiopathic intracranial hypertension.

Visual acuity loss and sixth nerve palsy as the only manifestations of slit ventricle syndrome

The case is presented of a girl diagnosed with obstructive hydrocephalus due to pilomyxoid astrocytoma, which required a ventriculoperitoneal shunt (VPS) at the age of 5 years and 10 months. Two months later, magnetic resonance imaging of the brain did not show ventriculomegaly or other signs of increased intracranial pressure. At the age of 6 years and 2 months, a rapid onset of bilateral visual acuity loss developed and she was diagnosed with slit ventricle syndrome. Despite valve revisions of the VPS, she developed an abrupt decline of visual acuity to hand motion at 10cm. Fundus examination revealed bilateral optic atrophy. She did not report any other systemic symptoms suggesting increased intracranial pressure, such as headache, nausea, vomiting, lethargy, irritability, or altered levels of consciousness.

Management of Hydrocephalus in Children: Anatomic Imaging Appearances of CSF Shunts and Their Complications

OBJECTIVE. This article addresses the management of hydrocephalus and the CSF shunts used to treat this entity. CONCLUSION. CSF shunts have a high failure rate. Imaging plays a pivotal role in assessing CSF shunt failure and determining the need for surgical revision. An in-depth knowledge of CSF shunt components, their failure modes, and the corresponding findings on anatomic imaging studies is necessary to ensure timely diagnosis and prevent permanent neurologic damage.