Gee...Next Monday sounds like a rather full day for you. To plan on doing anything on the following day might be pushing it. The MRIs will take at least an hour to do and you will have to lay flat on your back and not move during them. Then to follow that with the spinal and more laying flat right after for another while (depending on the technique used and how you are doing), might prove to be taxing.
I would be pretty stiff if I did all of that in one day; but that is just how my MS afffects the body.

There really is no way of telling ahead of time what you will be experiencing on Tuesday, or if you will need to be laying down for the whole day, but as laying down for around 24 hours after the spinal is recommended, that could mean that you may still be wanting to lay down on Tuesday morning.

Maybe you should call whomever is wanting to do the disability test and explain the situation to them. They might want to reschedule your Tuesday test because if you have any reaction to the proceedures done on Monday, it could affect the results of the disability test.
Mind you, that might not be a bad thing if you are being assesed for disability insurance.

The symptoms after the spinal vary from person to person; and a lot depends on the proceedure and the expertise of the practitioner who does it.
In the best case, there may only be a little tenderness at the puncture site. At the other end of the scale, there can be a headache, site tenderness and an increase in your usual MS symptoms (spasms, fatigue etc).

Try to get plenty of rest on Sunday and maybe spend some time doing something that you really enjoy doing so that your mind will be at ease as well.
I try to spend part of the day before a day of being in the hands of the medical system visiting with a friend, out in nature and/or in my garden. It gives me somewhere to rest my mind during the next day, instead of on what's being done.

I'm reallly wishing that your day on Monday goes smoothly and comes off without a hitch.
Holding you in that thought. ((((())))

With love, Erika