I think you have the real story. New active lesions show up on an MRI with contrast as white. Old lesions show up at gray or black. Old lesions can cause symptoms.
In MS, when there is a flare, old lesions can activate again and cause worsening symptoms. During a flare, a new lesion can develop. This would cause new symptoms.
Diagnosed with MS July 2006
I have no lesions on my soul and so I live with no limits.