Meniere's Disease Support Group
Meniere's disease is a balance disorder of the inner ear. The symptoms of Meniere's are variable; not all sufferers experience the same symptoms. However, "classic Meniere's" is considered to comprise the following four symptoms: Periodic episodes of rotary vertigo, hearing loss, tinnitus, and a sensation of fullness or pressure in one or both ears.
If it's not working he likely needs to try something else! Upper cervical care shouldn't last a long time you should only have to go a few times a year.
Also try finding someone who specializes in vertigo. GP's don't know what to do with it.