My husband had one monster exacerbation...his first "attack" in 2/07. He had pins and needles, trouble walking, bad pain, fatigue and spasms. It took about six weeks before getting diagnosed, since at first he thought it was a pinched nerve. After dx and steroids, he was left with fatigue, pain and spasms, but the pins and needles were gone and he could walk again.
No new MS symptoms since then, but the remaining symptoms are not the same every day. Some days the spasms are bad, some days the pain, and the fatigue is a constant. I don't think this is an "exacerbation" but is just from the damage done during his initial flare.
Some people recover completely after a flare, some are left with damage and continuing symptoms. I think the red flag is a new symptom...that usually signals an exacerbation.
hope this helps-
Husband dx RRMS 3/07
dx dual jugular vein stenosis (CCSVI) 4/09