Botox injections may ease the irritation of tinnitus

Sep 18 2004

A preliminary study indicates that Botox injections may ease the irritation of tinnitus, otherwise know as ringing in the ears, for some patients. Researchers say more study is needed, but initial results are promising.

Tinnitus, or the presence of noises (ringing, whistling, hissing, roaring, booming) in the ears, is a common complaint affecting an estimated 10-20 percent of the general population. Chronic, persistent tinnitus can affect one’s ability to work, engage in social activities, and sleep. For some, the problem is much more harmful, affecting their mood with resulting mild to severe depression. Five percent of the general population are affected by tinnitus to a severity that it causes them to seek help.

The clinical causes of tinnitus have been explored in an effort to explain why this disorder affects individuals so differently, with some having only mild recognition of the symptom and others having true annoyance and more serious interference with their quality of life. Many experts now believe that tinnitus is affected by the autonomic nervous system.

Botox is most commonly known as a remedy to diminish wrinkle and frown lines and for more serious medical conditions including strabismus, spasmodic altered voice production, failure of the voice muscles to relax, and cervical dystonia. More recently, Botox has shown significant benefit through nonparalytic effects for problems including neuropathic pain and migraines. Specifically, in management of migraines, Botox is suspected to block not only acetylcholine, but inhibit release of other neurotransmitters and neuropeptides important in the autonomic pathway.

With Botox having proven benefit in disease processes via blockage of autonomic pathways, and a significant aspect of tinnitus believed to be effected via the autonomic pathway, researchers set out to examine whether Botox could possibly impact the perception of tinnitus. The authors of “Evaluation of Botox in Treatment of Tinnitus,” are Katrina R. Stidham MD with the California Ear Institute at San Ramon, Perry Solomon MD, Director Bridges Medical Clinic for Botox rx for Migraines and Hyperhydrosis, and Joseph B. Roberson MD, California Ear Institute and Let Them Hear Foundation, all from California. Their findings are being presented at the American Academy of Otolaryngology-Head and Neck Surgery Foundation Annual Meeting & OTO EXPO, being held September 19-22, 2004, at the Jacob K. Javits Convention Center, New York City, NY.

Methodology:

Adult patients, 18 years or older were identified for a variety of problems including primary tinnitus, hearing loss, and Meniere’s disease. Those included in the study had unilateral or bilateral non-pulsatile tinnitus with audiometrically normal hearing; sensorineural, conductive, or mixed hearing loss for more than two months; no evidence of middle ear disease, chronic middle ear infection, or mastoid infection; asymmetric hearing loss with dizziness; and for females, concurrent use of a reliable method of contraception. Exclusion criteria included known allergy to botulinum toxin type A, any medical condition that may put the subject at increased risk with exposure to Botox â, use of aminoglycoside antibiotics, curare-like agents, or other agents that might interfere with neuromuscular function, throbbing tinnitus, upcoming neurotologic or otologic surgery for chronic ear disease, vestibular schwannoma, meningioma or skull base tumors, significant psychiatric history or associated diagnosis of major depression, younger than age 18 years, pregnancy, and concurrent tinnitus treatment.

Botox was reconstituted in preservative free saline with 2.5 cc of saline per 100 unit vial. The side of injection was chosen based on the patient’s subjective source of tinnitus in cases of unilateral tinnitus. For patients with bilateral tinnitus, the patient was asked to identify the louder side and if no louder side was notable, one side was arbitrarily selected for injection. When receiving Botox, the total dose was equally divided and injected into three sites around the ear; one cm above superior aspect of auricle, one cm behind auricle at the 2 o’clock position, and one cm behind auricle at the 5 o’clock position. When receiving placebo, equal amounts of saline were injected at each of these sites to match the Botox total volume.

Patients were placed into one of two treatment arms. Patients in treatment arm #1 received Botox at the first injection, and placebo at the second injection four months later. Patients in treatment arm two received placebo at the first injection and Botox at the second injection four months later. The lower dose of 20 units was injected in the first blinded treatment group (total 5 patients) to verify safety. All of the subsequent Botox injections were 50 units. All patients were blinded to the injections until at least four months after the second injection.

Due to the difficult nature to record and follow subjective tinnitus, several methods were used in an attempt to follow tinnitus for individual patients. Hearing was also closely followed. Subjective methods included questionnaires, Tinnitus Handicap Inventories (THIs), and tinnitus and hearing rating scales. All patients were asked to fill out tinnitus questionnaires prior to receiving the first injection. Questionnaires recorded data regarding length of tinnitus, side affected, and subjective description of tinnitus.

Results:

Twenty-six patients completed both injections and all follow-up and were included in data analysis. Following Botox treatment, subjective tinnitus changes included seven patients improved, three worsened, and sixteen unchanged. Following placebo treatment, two patients were improved, seven worsened, and seventeen unchanged. Comparison of the treatment and placebo groups was statistically significant (p<.005) when including better, worse, and same effects. Results were not statistically significant evaluating the better versus worse and unchanged effects combined. A significant decrease in THI scores between pre-treatment and four month post Botox injection (p=.0422) was recorded. None of the other comparisons of pre-treatment – one month, or pretreatment – four months were significantly different.

Conclusion:

In this study, Botox was used to treat a small number of patients with tinnitus originating from a variety of causes. While the results suggest a positive effect of Botox on irritation from tinnitus, the authors recommend a larger study to document repeatable results prior to drawing definitive conclusions regarding the potential benefits of Botox in treatment of tinnitus.