I would concurr with everyone as to seeing a qualified physician first and rule out any major conditions. If you are a member of DAN, they may be able to point you in the right direction.
Having said that, I would like to offer a different perspective as a pain therapist since I have treated a few clients (divers and surfers) with similar conditions. All the cases boiled down to stress placed around the shoulder and/or cervical areas through overuse (keeping the neck in certain position for extended periods, excessive force on the mouthpiece, etc) or mechanical load (equipment putting excessive compression at the base of the trapezius, excessively tight mask, whiplash from falls, etc).
The structures I addressed included splenius capitis, splenius cervicis, Trapezius I and II, Subclavius, Rectus Capitis, Cervical Multifidi, Masseters, Stylohyoids, Digastrics, Levator Scapulae, Scalenes, Suboccipitals, and Sternocleidomastoids.
Travell and Simon have documented all the effects the aforementioned structures have on the vestibular system producing effects such as vertigo, tinitus, ear ache, visual disturbances, among others. Their works can be found on "Myofascial Pain and Dysfunction"
The divers and surfers I treated were beginners and their bodies still getting acquainted with the mechanical demands of their activities, and anxiety exacerbated their discomfort.
Please do not take my advice as a diagnosis or course of action, only your physician can do that. I am simply offering a different perspective should your physician rule out any significant conditions and the diagnosis seems elusive (as was the case with my clients)
Wishing your wife the best and a prompt recovery.
