I have bouts of dizziness related to seasonal allergies. You might check your home for toxins and triggers. With hubby and I both of us are sensitive to dust. I have changed out all toxic cleaning materials in our home and we have two 'Austin Air' Air purifies one in our great room and a smaller one in the bedroom.
Doctor told me to position my head to shake loose possible 'crystals' in the ear but it seems like the ENT might have known about that- I think it is more of an alternative consideration. The Alt Doc I see just gently moved my head up and down and from side to side while I was lying down. He said I could keep trying that.
My last bout was cleared up when I had my ears cleaned out, but then surely your husbands ENT would have taken care of that.
MSG in food also affects my husband and I with dizziness- eating out can be a problem.
It really could be so many things! I feel for you. When it was at it's worst with me I was going crazy because it is so hard to function.
Oh, I just remembered the first time I had dizziness ENT Doc had me gave up cokes and diet drinks - I was immediately better and I have not had those for 12 years.I really don't think any carbonated drink is good. I mostly drink herbal tea and pure water now.
If I drink tons of water and juice veggies that are diuretic I sometimes throw my electrolytes off.
An Electrolytes formula my metabolic nutritionist gave me is
Na - (Cl + Co2) Reference Range: 9-18
ie Sodium minus (chloride plus Co2) should equal 9-18
When I was last dizzy my results for this formula was "7" he suggested I take 1/8 teaspoon of Celtic Sea Salt
in a small amount of water before my meals and that stop my dizziness.
Here are some ideals and some ranges:
Sodium (Na) Idea is 138 [135-146]
Potassium Ideal is 5 [3.5-5.3]
Chloride (Cl) [97-107]
Co2-bicarbonate level [23-26]
The fact that you sometimes get dizzy spells too makes me wonder if it is something in your meals together or in your home.
I hope some of my thoughts or others thoughts here help you-- keep seeking.
I Pray he is better soon-