Dilatation of the bridging cerebral veins in multiple sclerosis correlates with fatigue and suggests an increase in pressure

Pediatric interventional neuroradiology: "How I do it" vol. II-Embolization

Pediatric arteriovenous shunts can be challenging to embolize and the consequences of excess venous penetration disastrous. Moreover, the congenital nature of most shunts necessitates neonatal intervention whenever (medically refractory) heart failure occurs. Here, we describe current endovascular treatment strategies based on personal experience and literature review. While disparate, arteriovenous malformation, dural arteriovenous fistula (AVF), pial AVF, and vein of Galen aneurysmal malformation share unifying features such as high output heart failure and venous hypertension. This tutorial is divided into passages on Goals, Access, and Treatment which respect differences among pediatric arteriovenous shunts while maintaining a narrative economy.

Differential Analysis of Venous Sinus Diameters: Unveiling Vascular Alterations in Patients with Multiple Sclerosis

BACKGROUND

Alterations in the cerebral venous system have been increasingly recognized as a significant component of the pathophysiology of multiple sclerosis (MS). This study aimed to explore the relationship between venous sinus diameter and MS to understand potential vascular alterations in MS patients compared with controls. We sought to determine whether these alterations were correlated with disease characteristics such as duration, lesion type, and disability score.

METHODS

This study included 79 MS patients diagnosed according to the 2017 McDonald criteria and 67 healthy individuals. Magnetic resonance imaging (MRI) scans via a 1.5 Tesla system provided measurements of the superior sagittal sinus, right and left transverse sinus, sinus rectus, and venous structures. Statistical analysis was conducted via SPSS, employing independent sample t tests, ANOVA, chi-square tests, and Pearson correlation analysis, with the significance level set at p < 0.05.

RESULTS

This study revealed significant differences in venous sinus diameter between MS patients and controls, with MS patients exhibiting larger diameters. Specifically, patients with brainstem and spinal lesions had larger diameters in certain sinus regions. No significant correlations were found between venous sinus diameter and demographic factors, expanded disability status scale scores, or lesion counts. However, a significant increase in perivenular lesions was noted in patients with longer disease durations.

CONCLUSIONS

The findings indicate notable vascular alterations in MS patients, particularly in venous sinus diameters, suggesting a potential vascular component in MS pathology. The lack of correlation with conventional clinical and MRI metrics highlights the complexity of MS pathology. These insights underscore the need for further research, particularly longitudinal studies, to elucidate the role of venous changes in MS progression and their potential as therapeutic targets.

A perspective on the evidence for glymphatic obstruction in spaceflight associated neuro-ocular syndrome and fatigue

Spaceflight associated neuro-ocular syndrome (SANS) alters the vision of astronauts during long-duration spaceflights. Previously, the current authors have discussed the similarities and differences between SANS and idiopathic intracranial hypertension to try to elucidate a possible pathophysiology. Recently, a theory has been advanced that SANS may occur secondary to failure of the glymphatic system caused by venous dilatation within the brain and optic nerves. There is recent evidence to suggest glymphatic obstruction occurs in childhood hydrocephalus, multiple sclerosis and syringomyelia due to venous outflow dilatation similar to that proposed in SANS. The purpose of the current paper is to discuss the similarities and differences between the known CSF and venous pathophysiology in SANS with these other terrestrial diseases, to see if they can shed any further light on the underlying cause of this microgravity-induced disease.

The dilated veins surrounding the cord in multiple sclerosis suggest elevated pressure and obstruction of the glymphatic system

Recently, Clarke et al. published a study using spinal cord susceptibility weighted imaging in multiple sclerosis patients at 7T. They discovered dilated intradural extramedullary veins surrounding the cord. The purpose of this commentary is to point out some recent research by our group, which suggests this dilatation also occurs in the bridging cortical veins surrounding the brain. The dilatation indicates a focal elevation in the venous pressure secondary to impedance mismatching. Due to the shared outflow geometry, dilatation of the outflow veins will obstruct the glymphatic pathway of the spinal cord altering the immune response.

Syringomyelia Is Associated with a Reduction in Spinal Canal Compliance, Venous Outflow Dilatation and Glymphatic Fluid Obstruction

The cause of the cystic dilatation of the cord found in syringomyelia has been a source of conjecture for a considerable time. Recent studies have shown that there is a reduction in craniospinal compliance in both childhood hydrocephalus and multiple sclerosis which leads to venous outflow dilatation. Both diseases are associated with glymphatic outflow obstruction. Venous dilatation will narrow the perivenous glymphatic outflow pathway and lead to an increase in glymphatic outflow resistance. Syringomyelia has been shown to be associated with reduced spinal canal compliance. This paper discusses the possibility that venous dilatation and obstructed glymphatic outflow within the cord may be behind the cystic dilatation found within syringomyelia.