NAWM damage correlates to disability

[frodo]

Maybe lesions are not so important as we have always supposed.

Despite they are invisible to normal MRI, it seems that damage in the "Normal Appearing White Matter areas" (NAWM) correlates to disability, while number and amount of lesions do not (this is sometimes called the clinical-radiological paradox)

New modalities of MRI and PET now allow to see those NAWM areas.

Restriction spectrum imaging of white matter and its relation to neurological disability in multiple sclerosis

http://journals.sagepub.com/doi/abs/10. ... 8518765671

Results:

All tested RSI-derived parameters differed between WML and NAWM (p < 0.001 for all pairwise comparisons). The sADC in WML showed largest difference across disability subgroups (analysis of variance (ANOVA): F = 5.1, η2 = 0.12, p = 0.008). ND in NAWM showed strongest correlation with disability (ϱ = –0.39, p < 0.001).

Conclusion:

The strongest correlation with EDSS of ND obtained in NAWM indicates that processes outside lesions are important for disability in MS. Our study suggests that RSI-derived parameters may help understand the “clinico-radiological paradox” and improve disease monitoring in MS.