What the Mayo study doesn't mention
The study, at least the stuff I have looked at, does not mention the symptoms and lesion location of the patients so may give the impression that everyone with a low EDSS after 5 years or 10 years will have 90% chance of having benign MS.
But if you fall in to one of the below categories and don't have a particularly good neurologist and you only read the Mayo study then the chances are you may indeed believe you don't need any treatment. And this may not be correct.
1. They don't mention spinal lesion (s).
Spinal cord lesions are RARELY associated with benign MS. Even if you haven't had an attack in 5 years if you have spinal cord lesions the chances are it is not benign MS.
Demyelinating lesions in cervical spinal cord and disability in multiple sclerosis patients (2004 Jan-Feb)
http://www.ncbi.nlm.nih.gov/entrez/quer ... s=15049165
'Patients without demyelinating lesions in cervical cord had EDSS from 1 to 3 and the duration of their disease was longer than 10 years (benign MS). CONCLUSIONS: The duration of the disease depends on the presence and character of demyelinating lesions in cervical cord to a large extent. That dependence was not noticed in a primary progressive form. In benign MS there were no lesions in cervical cord.'
2. The only exception to this is appears to be, possibly. with acute posterior cord lesions, presenting as a cordonal posterior syndrome (that means sensory type stuff, sometimes brachial pain and ataxia, not weakness, bladder or other motor problems) and then it seems only to apply to women. Sorry guys.
Acute posterior cord lesions in multiple sclerosis. An MRI study of the clinical course in 20 cases (Dec 2000)
http://www.ncbi.nlm.nih.gov/entrez/quer ... s=11139729
'This study confirms the contribution of serial spinal cord MR studies to understanding the natural history and pathophysiology of medullary forms of MS presenting as a cordonal posterior syndrome. It also shows a good relationship between the clinical manifestations and course of this form of MS and the localization and variable morphology of plaques. Finally, our results suggest the predictive benign course for this medullary form of MS that seems to be almost exclusively restricted to the female gender.'
3. And finally, people with a high lesion load declared benign may still progress to SSPM at a later stage.
Brain and spinal cord MR in benign multiple sclerosis: a follow-up study.
http://www.ncbi.nlm.nih.gov/entrez/quer ... ds=8981313
'This study suggests that patients with benign MS have two different patterns of disease evolution, one characterized by very low clinical and MR activities, the other in which the lack of disabling symptomatology might be related to factors like site, size and nature of lesions. It also indicates that in patients with benign MS and high MR lesion loads the risk of developing a secondary progressive form of the disease is still present even after many years after onset. '
Felly (the voice of doom)