I have tinnitus -- high-pitched ringing/hissing in my ears. Hearing tests have shown I have high frequency hearing loss. I'm also being treated for TMJ problems by a neuromuscular dentist. My ENT doctor at UCLA has me trying 20mg of Namenda per day. It's a drug that's normally used to treat Alzheimer's disease. It works by reducing the amount of glutamate being produced by the brain, thereby softening or eliminating the ringing in my ears. I've been on the Namenda for about 5 weeks. I can't really tell if it's working or not. Most days, the ringing is still very loud, but some days it's softer. Still ringing 24/7, though. Anybody here have any luck with Namenda (memantine)?