My Husband Has Some Weird Symptoms That We Cannot Trace

my husband has some weird symptoms that we cannot trace to anything. He feels dizzy, has ear ringing, burred vision and sometimes feels like he is having an out of body experience. He is very sensitive to motion and sound. We've seen our family doctor, and ENT and he is now scheduled to see a neurologist. The ENT does not believe it is benign positional vertigo or vestibular neuritis. These symptoms started in summer 2013, and he has had 4 bouts of it since then. It takes about 2-3 months for the symptoms to subside completely.. My husband says that the symptoms are getting worse each time.