Different white matter lesion characteristics correlate with distinct grey matter abnormalities on magnetic resonance imaging in secondary progressive multiple sclerosis.

BackgroundAlthough MRI measures of grey matter abnormality correlate with clinical disability in multiple sclerosis, it is uncertain whether grey matter abnormality measured on MRI is entirely due to a primary grey matter process or whether it is partly related to disease in the white matter.MethodsTo explore potential mechanisms of grey matter damage we assessed the relationship of white matter T2 lesion volume, T1 lesion volume, and mean lesion magnetisation transfer ratio (MTR), with MRI measures of tissue atrophy and MTR in the grey matter in 117 subjects with secondary progressive multiple sclerosis.ResultsGrey matter fraction and mean grey matter MTR were strongly associated with lesion volumes and lesion MTR mean (r = ±0.63–0.72). In contrast, only weak to moderate correlations existed between white matter and lesion measures. In a stepwise regression model, T1 lesion volume was the only independent lesion correlate of grey matter fraction and accounted for 52% of the variance. Lesion MTR mean and ...