What is Progressive Multiple Sclerosis?
Some patients develop symptoms slowly and gradually, progressive over 6 to 12 months or more.
If this gradual worsening develops after an initial relapsing remitting disease course, it is referred to as secondary progressive Multiple Sclerosis.
Approximately 10% to 15% of all Multiple Sclerosis patients never experience a CIS or a relapse but rather have chronic progressive symptoms from the onset.
This is referred to as primary progressive Multiple Sclerosis.
The only distinction between these progressive forms is the presence (secondary progression) or absence (primary progression) of relapses prior to the appearance of the progressive symptoms.
There are otherwise no known pathophysiological differences between the two forms.