Information on strokes

My father has just suffered a stroke and he has slurred speech and lost some mobility in his left side.
Some people have said to me that the symptoms on the left side imply a right-brain stroke and that this is not as severe as a a left-brain stroke. Is this true? What is the difference? Are symptoms likely to be permanent or do the effects of a stroke normally diminish with time?

Until those with medical knowledge get here: here’s a couple of links.

Doctor’s Guide

BBCNews-Health

My mother had a series of strokes over the last years of her life. There were always some lasting effects, from the debility of her left leg to her difficulty with spelling out simple words (however, she could speed read with th’ best of 'em). I’d say the effects and their duration would depend on the severity of the stroke and the location of the damage to the brain.

Some effects can be lessened with therapy. Don’t give up.

Somnambulist, I don’t have any information on strokes, but I’m here to wish you and your father well, and to hope that he will be able to recover as much as possible.

I don’t know if it’s normal, but my roommate’s grandfather suffered a stroke, was almost paralysed in one side of his body, but has now almost totally regained mobility. So it happens, at least.