Small AN with Big Symptoms
Debi had a small intracanalicular acoustic neuroma (AN) (9mm). She started to get dizzy and unbalanced with tinnitus and fullness in right ear in late September 1997. First step to the family doctor. He referred her to an ENT. It was now late October, hearing test normal. ENT suggests maybe its Meniere's Syndrome, try taking some lypoflavinoids and call us if anything gets worse.
Early November, hearing in right ear starts to rapidly diminish. Hearing test shows a drop in speech reception threshold (SRT) and speech discrimination score (SDS). A low dose of prednisone (a steroid) is prescribed for about a week. Hearing improves at start of prednisone but diminishes as dose goes down. ENT then sends Debi for a CT scan which did not identify the AN. Through November hearing continued to decline, but responded to higher doses of prednisone. Every time the dose of prednisone was lowered, hearing declined. Then when restarting prednisone at a higher dose hearing improved but it never came back as good as it had been previously. At the low points, hearing in the right ear had a 70dB SRT and 0% SDS. We did our homework, and got another ENT who recommended an MRI which identified the AN on November 24th.
I think this info about prednisone helping a patient to retain hearing is very important to newly diagnosed patients with small ANs. In layman's terms, what they think could be happening in a case like this is that the AN puts pressure on the tiny artery that runs through the inner auditory canal and leads to the cochlea (inner ear). If the flow of blood is cut off to the cochlea, important cells there can be severely damaged or die. Those that die will not grow back and hearing will be permanently lost. When the patient takes prednisone, swelling in the area around the AN is reduced and the flow of blood can get through to the cochlea, and preserve hearing. There are a few medical journal papers which discuss some of this ever so briefly. There also are a few that mention fluctuating hearing levels similar to what Debi was experiencing. Let me know if you want references.
So November 25th we started a crash course in AN-ology. We learned all about gamma knife, FSR, Middle Fossa, Translab, and Retrosigmoid. Like most people learning about AN, we did not know any of this, we did not even know our parts of the brain. It's hard to imagine all that we had to learn. We know we can't find all the answers and can't understand all the complexities. However, if we have done our homework, we sure do have a much better understanding of what our doctors say, and we are much more able to ask the right questions.
We saw four different surgical teams. One of them we were not comfortable with because they bragged of a quick surgery, but had a low hearing preservation rate. The neurosurgeon here said that if we could find someone who had their AN removed and still had useable hearing, he would like to see them. Then we had conflicting recommendations on approaches from two others, so we went to a fourth for a final opinion.
A few days before surgery, Debi had a hearing test that was not good. It showed a 65dB SRT and 10% SDS in the affected ear. Debi had the Retrosigmoid approach done at New York University Medical Center by Dr. Noel Cohen (Neurotologist), Dr. J. Thomas Roland (Neurotologist), and Patrick Kelly (Neurosurgeon). Dr. Cohen has removed many ANs and has published his results. In Debi's particular case it was important that the AN did not reach the lateral end of the inner auditory canal.
The surgery took about 7 hours. It felt much longer to me than to Debi. The tumor resection was complete. She has had no facial paralysis or weakness. No CSF leak. No severe headaches (not one Tylenol since the surgery). When they took off her bandages a few days after surgery, she had no hearing, but a couple days after that her hearing came back.
A hearing test 10 days after surgery had an SRT of 25dB and SDS of 80%. This was a remarkable improvement. Since that test, Debi has noticed even more improvement in hearing. Hearing at one month after surgery had an SDS of 100%. Her June 1998 hearing test was excellent with 100% SDS and an SRT of 20dB. Restoration of hearing from low levels to levels like these is very rarely reported. We feel it is the result of her particular AN situation, including size and location of her AN, pre-surgical prednisone treatment, little delay between diagnosis and removal of the tumor, and the use of a very experienced AN surgical team.
The only problems from surgery were the 99% temporary imbalance problems from losing the vestibular nerve on the right side and fatigue from major surgery.
We feel like we took the best approach that we could with the info we could get. In Debi's case, a quick action was warranted by her specific symptoms. If she did not take the prednisone, she probably would have permanently lost the hearing in the right ear. If she stayed on the prednisone too long, she would have suffered from the side effects caused by the long term use of high doses of prednisone which can be permanent. So we did not want to wait too long before taking action. The location of her particular AN allowed for a hearing preservation attempt via the retrosigmoid approach which involves less risk to the facial nerve than the Middle Fossa approach. Debi is a young 41 and we have four children aged 4-14, so we did not want to take any long-term risks with radiation. If she was 65 and only expected to live another 20 years anyway, then radiosurgery such as FSR would have been in the running.
What I think we can learn from Debi's case is: that early diagnosis of an AN, while it is still small can lead to hearing preservation; that the use of prednisone may help some patients with small ANs retain hearing while they investigate their options; that sometimes you can preserve hearing by getting treatment quickly; that hearing can be restored to levels higher than those immediately preceding treatment; that today's handful of experienced AN surgical teams can get us through the surgery without some of the more commonly reported complications; and that every AN case is different.
Please understand that we are not saying that the treatment method we chose would be best for anyone else. Clearly, she could have lost all hearing and facial function on the operated side. There may have even been a better way for us to go, but this is what we chose, and we thank God that everything came out good.
As always, every person and every AN are unique. If you have any questions about Debi's case or ANs in general, feel free to write us.
Steve & Debi Spayd <spayds AT voicenet.com>
Last Edited: Wednesday, October 30, 2002