Drugs are not working for cerebral vaculitis - what else can we try?

A very close friend of mine was taken ill over Christmas 2007 and is still in hospital.  He was diagnosed with ADEM after around 4 weeks and given steroids which improved his condition initially but then he started to deteriorate again.  He was then diagnosed with cerebral vaculitis one month later and given steroids and low dose immuno suppressant chemotherapy to try to prevent the immune system damaging the brain.  An MRI showed lots of mini strokes in the brain which explained the confusion and memory loss and he also had a biopsy taken.  After a slow and steady recovery, in May he was discharged from hospital and continued recovery at home which was progressing really well, until a sudden deterioration at the end of May and he is still in hospital, very confused and not up to visitors so I have not seen him for a couple of months.  The medics have tried every treatment they can think of but nothing is working.  They are now looking for a special licence in order to try an experimental drug.

Prior to hospitalisation, my friend held down a high pressured job and had high stress levels as well as spending a lot of time away from home as a result of business travel all over the world.  In November he'd been sent home from work having had dizzy spells, high blood pressure and feeling faint and confused and went to see his doctor but returned to work as normal soon afterwards.

Does anyone know anything which may be useful in trying to find a treatment that might help?