I'm interested in this question myself. I noted the other day that I had always read that O-bands are permanent, so I wondered if that was truly the case. No one answered at that time.
So, I just tried a quick Google query and came up with this Wikipedia quote, which gives a convincing argument
against using Wikipedia as a single information source...
From Wikipedia:
"Oligoclonal bands are an important indicator in the diagnosis of multiple sclerosis. Approximately 79%-90% of all patients with multiple sclerosis have permanently observable oligoclonal bands.
The presence of one band (a monoclonal band) is not considered serious and may simply be normal. More bands may reflect the presence of a disease. The bands tend to disappear from the cerebrospinal fluid as a person recovers from the neurological disease."
Anyone else want to answer this question for us?

Wonder if the bands are only
permanent as long as MS is
permanent? Until now, MS actually HAS been permanent.