Been a bit busy, otherwise, would have replied earlier, sorry...
I have only ever had IV Solumedrol, never oral - in my country, the docs reckon that oral doesn't do much good for ms inflammation, and I haven't had another condition that required oral steroids.
But your question pertained to iv...I can't really exactly remember how long it took me to definitely better the first time I had a course, but I think that first bad relapse that they treated with ivsm lasted a good 6 weeks, with residual symptoms still present today. Subsequently, I have had several courses (1000mg per day, for 5 days), and my recovery usually starts about 2 weeks after steroids - but the recovery is not always complete - I am usually left with something new to deal with! I am lucky thou - the first 6 years or so of my ms, I always recovered completely, never had 'serious' deficit, and didn't require interferons. Only the last 3 years or so have been a little tougher.
Last point - my Oncologist (long story) has warned my that we have a lifetime limit for ivsm at such high doses due to cardio-toxicity: you may have up to 60 doses of 1000mg (not courses) over your lifetime, then there can be problems. She knows this as she deals with steroids a stack - brain tumours, side effect treatment etc with chemo - she usually uses Decadron, but has used most of the steroids. I only mention this as I have not heard it discussed on the boards and it might be important to someone.
Ivsm is a bit of a burden - I become a seething bitch who disolves into tears on a whim for at least a week or two after my steroids, plus my face goes bright red, I get hot flushes, sweating, palpitations, insomnia...! But 'no pain, no gain' - the side effects are transitory and hopefully the reduction in inflammation can only benefit us. So it is a trade off to me.
Hope all goes well and that you see some real gain soon.
I am a real animal lover - got 2 cats and 4 dogs...Plus 2 kids!