This study compared white matter signal abnormality characteristics and the prevalence of radiologically isolated syndrome (RIS) in healthy subjects selected randomly from the population with the healthy relatives of people with MS. It included 82 non-familial healthy control subjects and 68 healthy relatives with MS (if they had ≥1 relative affected with MS).
The presence of RIS was evaluated according to the Okuda criteria and Swanton criteria. The researchers found a significantly higher total volume of white matter signal abnormality in healthy relatives of people with MS compared with the non-familial healthy control subjects. 8.8% of the healthy relatives of people with MS and 4.9% of non-familial healthy control subjects showed ≥9 white matter signal abnormalities. 2.9% of subjects in the healthy relatives of patients with MS group and 2.4% of non-familial healthy control subjects fulfilled RIS according to the Okuda criteria, whereas 10.3% and 3.7% of subjects fulfilled RIS according to the Swanton criteria. Smoking was associated with the presence of white matter signal abnormality and obesity was associated with ≥9 white matter signal abnormalities in the healthy relatives of patients with MS and to fulfillment of radiologically isolated syndrome according to the Swanton criteria. In the future, longitudinal studies are needed to see if asymptomatic healthy controls fulfilling the RIS-Swanton criteria have an increased risk of developing MS.
Authors: Gabelic T, Ramasamy DP
Source: AJNR Am J Neuroradiol. 2013 Jul 25. [Epub ahead of print]
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