Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to examine you and obtain a history, I can not tell you what the exact cause of your symptoms is. However I will try to provide you with some useful information.
I am not sure what you mean by the term dizziness. When some people use the term dizziness, they often mean vertigo, or room-spinning. Others mean a light-headed, whoozy feeling.
If by dizziness you mean vertigo (room-spinning), the causes could be either the inner ear or the brain. Inner ear causes of vertigo most commonly include benign positional vertigo (BPPV), which is due to small particle in the inner ear that moves out of place, and can be repositioned with simple head maneuvers. The symptoms often include vertigo that occurs with turning of the head, often while turning over in bed, which it sounds like is the case in you. Another cause, if your symptoms are associated with tinnitus (ear ringing), which it sounds like you have, and hearing loss is called Meniere’s disease and can be treated with medications and sometimes surgery. And so on, several other causes from inner ear problems exist. It sounds like your ENT did not feel these were potential causes to your symptoms, so these may not be the cause, but in general these are causes of vertigo. If you did not have a hearing test, this may be worth doing, as in most cases of Meniere's disease, hearing tests will be abnormal, pointing to the diagnosis.
Vertigo can also be due to problems in the brain. A normal MRI of the brain, which it sounds like you have had, excludes multiple sclerosis and tumors as a cause. Thyroid problems can also lead to vertigo.
Your symptoms may be consistent with a variant of migraine called basilar migraine, and your vision symptoms could potentially be opthalmic migraine as suggested by your physicians. Basilar migraine is basically marked by several hours of vertigo associated with nausea, light-sensitivity, and sometimes other symptoms. Headache may or may not be present. The treatment is different from that used to treat other migraine types; the treatment in this case is a type of medication called calcium channel blocker, such as verapamil, which is actually used to treat blood pressure but works in type of basilar migraine as well. As you mention above, these types of migraine would be expected to be episodic rather than daily as in your case.
If by dizziness you mean light-headedness, causes could include low blood pressure such as due to dehydration or autonomic dysfunction, cardiac problems, thyroid problems, and several other non-neurologic causes. Anemia can cause light-headedness as well.
To my knowledge, pseudotumor does not run in families. However, it can cause symptoms of vertigo and ear ringing with vision symptoms. Your eye doctor would have most likely been able to pick up any swelling of the optic nerve (papilledema) which occurs with pseudotumor.
Continued follow-up with your neurologist is recommended. If it is thought that your symptoms could be migrainous, treatment with migraine medications may help you. If on re-evaluation they are thought to be from the inner ear, then techniques to treat BPPV are available, there are also treatment for Meniere's, and also vestibular rehabilitation may be beneficial to you.
Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.
Thank you so much for your response! I am happy with the visual migraine diagnosis from my doctors, but can a visual migraine be every day and pretty much all day? Is this what is knows as persistent visual migraine? Thank you for your response, it is very helpful!