What you are describing seems to be recurrent episodes of nausea which was random in nature initially, but now mostly nocturnal. You also indicate an acid reflux problem.
What is notably missing in your account is any mention of tinnitus or a 'typical' vertigo. Thus, to attribute this symptom to the inner ear may be difficult (but not impossible).
Benign Paroxysmal Positional Vertigo (BPPV) is one condition which needs special mention.This is more common with advancing age. Mostly idiopathic. Nocturnal vertigo and nausea are known to occur due to changes in body position such as, turning in the bed. Can occur sometimes following head trauma, ear trauma, inner ear surgery and other conditions.Believed to be due to abnormal collection of "otoconia"- debris which migrate into the semicircular canals.
Acid reflux is certainly capable of causing nocturnal nausea as well as the 'gagging' that you are referring to.
Apart from this, there are certain less common conditions also merit consideration.
- Certain migraine variants [nocturnal migraine- migraine aura without headache
- Temporal lobe epilepsy (TLE) and complex partial seizures (CPS) occurring exclusively or predominantly nocturnally (can present as nausea or vomiting, without obvious 'fits').
I am not aware if you have already consulted a gastroenterologist for your reflux symptoms, which need to be investigated first. As your doctor had suggested, you may need a CT or MRI of the brain. Your doctor is certainly in a better position to guide you.
MB BS, MS, FRCS(Edinburgh)