Revesz et al. A comparison of the pathology of primary and secondary progressive multiple sclerosis. Brain. 1994 Aug;117 ( Pt 4):759-65.
The course and disease pattern of PPMS differ from those of the more common SPMS form.
The observation by MRI that the frequency of enhancement with gadolinium (intravenous contrast material), a marker for blood-brain barrier leakage, is significantly less in the PPMS form, has led to the hypothesis that inflammation is less intense in this group.
To test this, the investigators studied postmortem material from 9 cases judged from a retrospective analysis of case notes to show clear clinical evidence of either PPMS or SPMS disease. 578 lesions were analysed. There was significantly more inflammation in SPMS (as judged by the frequency of perivascular (around blood vessels) cuffing and cellularity (number of cells) in the brain tissue) than in PPMS disease. These observations have implications for therapeutic strategies in progressive MS.
“I am aware that this is an old study. However, it demonstrates that there may be a quantitative difference in the amount of inflammation between PPMS and SPMS, but not a qualitative difference. This means that under the microscope both types are similar. In addition, to this there is a large amount of other data suggesting that PPMS is not different to SPMS.”
“Did you know that it not uncommon in siblings pairs with MS for one to have relapse-onset disease and the other to have PPMS? The figure from the UK sibling study is in fact 23% (please see article and table below). This indicates to me that relapse onset and PPMS are likely to be the same disease.”
|(33.7+27) / (84+68.3+33.7+39.3+27+9.7) x 100 = 23%|