If your epilepsy has been under control for over 10 years, I would see no reason for any seizures to increase, since apparently you have already had relapses of your MS.
I frankly do not understand why your doctor wants to do an LP and put you through that, when it's already confirmed that you do have MS. The results of the LP would not change the course of treatment.
As you know, epilepsy can remain quiet or crop up for what seems like no apparent reason. If your seizures are well-controlled now, I do not believe that they will increse due to relapses. My sister-in-law had epilepsy all of her life and did seem to have an increase in her seizures when she was under great periods of stress. If you course does not run that way, I wouldn't worry about a sudden incease.
This is a concern that you should speak to your doctor about.
And welcome to the MS Forum. You've come to a great place for friendship and understanding of this wasky disease. I am sorry that MS has brought you here.
Much Friendship and Best Wishes,
Heather
Welcome to the forum!
Good luck w/your LP on Thursday. Like Heather says, not sure why they want an LP to confirm. People are dx'd without it too.
Hope all goes well. Let us know how you make out,
-Shelly