My doctor prescribed Lithium to me.I found this series of schematics:
Lithium's Mechanism of Action: An Illustrated Review
Lithium also might help hydrops:
Effects of Lithium on Endolymph Homeostasis and Experimentally Induced Endolymphatic Hydrops
Which does make it seem like it might be helpful but I'm not sure if a) they understand all the effects of lithium yet and if b) the neurotransmitters in the cochlea itself are affected to any great degree (I can't find any information anywhere on that).
I would absolutely ask your neurologist specifically about this, though.
I really need to try something that works for my brain.