Did it really give you relief or only surgery did? how would you rate the 3 most successful treatments that you have tried? 1) Surgery 2) Retigabine 3) Tegretol and would you care to give them numbers please? Your case is like a guideline for others you know, you have tried nearly EVERYTHING!
It is not easy to answer. My condition has changed for the worse as a result of the improper use of hearing aids. In any case, if you have a clear diagnosis of neurovascular conflict,you have many drugs choices available. Surgery should always be the last resort. Does not guarantee results, and the data in the literature are in conflict. In my case it worked gaving partial relief.
With regard to drugs: Tegretol gave relief. Other (Gabapentin, Lamictal, Topamax ... etc.etc) not.
When I got worse in 2013, I made several attempts pharmacological. The most valid but with the huge problem of physical and mental addiction was Clonazepam.
Trobalt was excellent with low doses 100x3. It has much higher success rate than Tegretol in tinnitus disease but we have not officially papers about it. Unfortunately, due to significant side effects, I could not continue and I'm trying another way Keppra but it is too early to talk about results.
Whatever you're taking, if it does not work, follow always made by a neurologist of confidence. Do not go it alone.
Among the other drugs that have given temporary relief, only to lose effectiveness mysteriously, there is Cinnarizine or even better Arlevert or Arlevertan...dependig by your country (Cinnarizine + dimenhydrinate). is successfully used for Meniere's disease. It acts as a calcium antagonist on CNS suppressing hyperactivity coming from the periphery (Labyrinth).
I can not give advice because I'm not a doctor, but I'm sure you have a good chance of being able to find relief. Tinnitus is a multifactorial problem. I doubt that we will have a single pill that will solve our problem.
In case of conflict neurovascular rest of the opinion that the Tegretol was the best. It is no coincidence, it is a drug of choice for the treatment / pain of trigeminal neuralgia (who result a problem related to vascular conflict between the facial nerve VII and bloodvessel. The trigeminal nerve is the seventh cranial nerve very close to VIII (where you have the problem). You could benefit from them. Talk with your neurologist. The Trobalt is completely different.
The last important thing: neurovascular compression not ever is cause of tinnitus. All can born with a NVC on evidence on MRI scans but not ever it cause tinnitus...then: Make an ABR exam. If the waves IPL I and III are altered the conlict could be real the cause of your tinnitus. Another thing: have you got some TIC or Hemifacial spasm or sudden and fluctuanting hearing loss? To predict better the results of eventual surgery make also a Stellate ganglion blocking on the side of tinnitus and other test with intravenous lidocaine! Complete this step. Is most important for you if you are going on surgery.
I hope to be helpful
Best regards