MedicalResearch.com Interview with:
Netta Levin MD PhD
Hadassah Hebrew University Medical Center
MedicalResearch.com: What is the background for this study?
Response: Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system, manifesting with episodes of local inflammatory processes, called relapses. The most useful surrogate laboratory test for MS is magnetic resonance imaging (MRI), in which dissemination of demyelinating lesions in space and time are the hallmark of the disease. However, there is a discrepancy between the lesion load – the number, size, and location of the lesions – and the clinical state of the patients, reflected in their disability. This discrepancy is known as the “clinico-radiological paradox” and suggests that something other than the well-known mechanisms of demyelination, remyelination, and axonal loss may tip the scale of recovery from an acute episode. Global effects of the local damage and compensatory mechanisms were suggested as an explanation to this paradox.
In this study, we compared the visual system of patients with clinically isolated syndrome optic neuritis (ON) to patients with clinically isolated episodes in other functional systems, exploring changes, both anatomical and functional, caused to the system following the demyelinating episode. Optic neuritis was deemed a good in vivo model for studying the pathophysiology of tissue damage and repair in MS due to its characteristic clinical manifestation and to the visual pathways’ amenability to investigation using various techniques. To assess anatomical wiring ,i.e the white matter fibers themselves , we used diffusion tensor imaging (DTI). To assess functional networking as reflected by signal synchronization between distinct brain regions, we used resting state fMRI.