An ENT (ear, nose and throat) specialist should assess and direct treatment, if any, or at least try.

Sometimes manipulations (ENT showed my dad what to do - lay down on back and bring knee to chest, hold with opposite hand and turn head. forget which way - he had positional vertigo - dizziness onset by turning head. )

Some Rx medications may help vertigo.

In severe cases, or a desire to eliminate the dizziness, oto specialists offer infusion therapy-(laser pinholes into eardrum? and you lay on your side till the meds have dripped into the ear. about 2 hours, usually X3 days of treatment. Shea Ear Clinic, Memphis, TN offers this)

May be a candidate for vestibular rehabilitation. That entails exercises for corridination and balance, movement without dizziness, focusing on a main focal point, exercises that you can do yourself. May help some. He would need a physician's order for physical therapy for vestibular rehabiliation.

Maybe dietary changes - low sodium and no cola-caffeine drinks. probably water for that too.

I would think time would also be his friend to healing and overcoming vertigo. The body is amazing sometimes that way.

Hope he gets better.