Changes in the retinal veins in acute optic neuritis

Pediatric Central Retinal Vein Occlusion Secondary to Concurrent Mechanisms of Optic Neuritis and Antiphospholipid Syndrome

Purpose: To report a pediatric case of optic neuritis with subsequent development of central retinal vein occlusion (CRVO). Methods: A case and its findings were analyzed. Results: A 16-year-old boy presented with painful vision loss in the left eye, an afferent pupillary defect, and optic disc edema. Magnetic resonance imaging showed optic nerve enhancement and contrast-enhancing cerebral white-matter lesions, consistent with optic neuritis and demyelinating disease. He received intravenous methylprednisolone followed by a prednisone taper. At the 3-week follow-up, the visual acuity (VA) in the left eye had worsened and fundoscopic examination showed a new CRVO. A hypercoagulable workup showed antiphospholipid syndrome, which was treated with warfarin. He received intravitreal antivascular endothelial growth factor treatment with subsequent improvement in VA and resolution of the macular edema. Conclusions: This case describes an unusual mechanism for CRVO via a combination of optic disc edema from optic neuritis and hypercoagulability from antiphospholipid syndrome. It is important to recognize this complication of optic disc edema and the necessary workup for a pediatric CRVO.

Venous endothelial injury in central nervous system diseases

The role of the venous system in the pathogenesis of inflammatory neurological/neurodegenerative diseases remains largely unknown and underinvestigated. Aside from cerebral venous infarcts, thromboembolic events, and cerebrovascular bleeding, several inflammatory central nervous system (CNS) diseases, such as multiple sclerosis (MS), acute disseminated encephalomyelitis (ADEM), and optic neuritis, appear to be associated with venous vascular dysfunction, and the neuropathologic hallmark of these diseases is a perivenous, rather than arterial, lesion. Such findings raise fundamental questions about the nature of these diseases, such as the reasons why their pathognomonic lesions do not develop around the arteries and what exactly are the roles of cerebral venous inflammation in their pathogenesis. Apart from this inflammatory-based view, a new hypothesis with more focus on the hemodynamic features of the cerebral and extracerebral venous system suggests that MS pathophysiology might be associated with the venous system that drains the CNS. Such a hypothesis, if proven correct, opens new therapeutic windows in MS and other neuroinflammatory diseases. Here, we present a comprehensive review of the pathophysiology of MS, ADEM, pseudotumor cerebri, and optic neuritis, with an emphasis on the roles of venous vascular system programming and dysfunction in their pathogenesis. We consider the fundamental differences between arterial and venous endothelium, their dissimilar responses to inflammation, and the potential theoretical contributions of venous insufficiency in the pathogenesis of neurovascular diseases.

CCSVI is associated with multiple sclerosis

OBJECTIVES

To analyze all the arguments against chronic cerebrospinal venous insufficiency (CCSVI) as a medical entity, and its association with multiple sclerosis (MS) and to revise all the findings suggesting a possible connection between these two entities.

METHODS

We revised the methodology and results of all fourteen published studies on prevalence of CCSVI in MS patients. Furthermore, we take into consideration other work dealing with possible causes and explanations of venous, as well as vascular dysfunctions linked with MS.

RESULTS

Studies of prevalence show a great variability in prevalence of CCSVI in MS patients. However, a recent meta-analysis assessed an over 13 times increased prevalence in MS. Global hypoperfusion of the brain, and reduced cerebral spinal fluid dynamics in MS was shown to be related to CCSVI. Post-mortem studies show a higher prevalence of intraluminal defects in the main extracranial vein in MS patients in respect to controls.

DISCUSSION

Taking into account the current epidemiological data, the autoptic findings, and the relationship between CCSVI and both hypoperfusion and cerebrospinal fluid flow, CCSVI can be inserted in the list of multiple factors involved in MS pathogenesis. Our careful data analysis may conclude that great variability in prevalence of CCSVI in MS patients can be a result of different methodologies used in venous ultrasound assessment. Finally, it has been proven that CCSVI share the three main risk factors with MS. On the other hand, smoking is the most important risk factor for endothelial cell damage, vitamin D has a protective role and Epstein-Barr virus passes the blood-brain barrier by invading the endothelial cells, therefore, epidemiologically, linking the imbalance of these three factors to MS through autoimmunity.