Thanks medchick.
That's worrying though as he has been in bed 2 weeks now and, if anything, the symptoms are getting worse.
According to eMedicine
"Most patients recover from severe vertigo and imbalance within 1 week. A minority have recurrent, less severe attacks."
For any other questions you may have... here is the article I read http://www.emedicine.com/emerg/TOPIC637.HTM
Although it contains a **** load of medical jargon, it should answer most anything!