So many diagnosis,Frustrated...Confused plz help !!

Sir,
I wad dxd PPMS in 2003,Aquiductal Stenosis in 2003,Non-compressive myelopathy in 2004,Demyelination & ?Prograssive MS in 2006 and now After all blood,nerve,thyroid test and MRI of dorsal spine and brain the doctors are also confused to give a correct diagnosis.I had have three relapses in 2003,2006 & 2009.but as per the doctors no new lesson found in the MRI excepting the demyelination found in the first MRI in 2003,the symptoms are also more or less the same like * Lack of balance *Walking Difficulties *Bladder,Bowel Dysfunction etc.The severity of the symptoms increases with each relapse.I had have two episode of vertigo in 1994 and 1996,once with vomiting and  the other without.
plz let me know what are the area like "VESTIBULAR PATHOLOGY" i should look into to arrive at the correct diagnosis and treatment there of.

with best regards,