This multi centre, retrospective study, looked at the relevance of brain lesion location and frequency in predicting 1-year conversion to MS. They used lesion probability maps (LPM) to assess, in a large population of people (1,165) with clinically isolated syndrome (CIS), differences at baseline in brain lesion distribution and frequency between CIS patients with different types of clinical onset and between patients who converted or did not convert to clinically definite MS (CDMS) within 1 year.
At 1 year, CDMS developed in 26% of patients. The converting group, had a greater baseline lesion load compared with the non-converting group, but showed less widespread lesion distribution. Those that converted had the highest lesion frequency in projection, association and commissural tracts of the white matter, in particular those traversed by fibres involved in motor function and close to the corpus callosum.
Therefore, the involvement of specific white matter tracts, in particular those traversed by fibers involved in motor function and near the corpus callosum, seems to be associated with a higher risk of conversion to MS in the short term.
Authors: Giorgio A, Battaglini M, Rocca MA
Source: Neurology. 2012 Dec 5. [Epub ahead of print]
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