By Barry Keate
Editor’s Note: Last month QT published an article that discussed new drug treatments for tinnitus. A QT contributing author, Charles Smithdeal, MD, directed us to yet another drug treatment and studies.
Tinnitus is often caused by hearing impairment which, among other causes, can be the result of reduced blood circulation to the inner ear. Micro-thrombosis and/or micro-embolism can cause this reduced circulation. They both involve blood clots blocking flow in the affected area. In the case of thrombosis, the clot is lodged at the location where it was formed and with embolism, it was brought to the present location by blood flow.
This blockage can be the result of inflammation due to infection or of autoimmune response, such as systemic lupus, where the body develops an allergic reaction to its own tissues. There is no widely accepted medical protocol for the treatment of this condition. The most commonly used medications are corticosteroids, vasoactive agents, vitamins and minerals, and anticoagulants.
Two clinical trials conducted at the ENT Department at the University of Genoa in Genoa, Italy have used sodium enoxaparin (trade name Lovenox) to treat this blockage. Enoxaparin is a low molecular weight fraction of the anticoagulant heparin. Due to its low molecular weight it exerts its effects primarily in the capillaries, the very small vessels that feed the inner ear. This medication is also indicated in the treatment of unstable angina, heart attack, deep vein thrombosis, obesity, varicose veins and many other conditions.
The first study 1 was published in 2003. The researchers involved 40 patients between 20 and 65 years old who had experienced tinnitus and hearing loss of 30 dB involving the medium frequencies between 2,000 and 4,000 Hz for at least 2 months. The patients were divided into two groups and admitted to the hospital for 10 days, the duration of the study. The first group received subcutaneous enoxaparin twice daily and the second group received traditional therapy.
On discharge, all patients treated with enoxaparin experienced a subjective reduction of symptoms. On a scale of 1 to 4, with 4 denoting incapacitating tinnitus, the mean value of symptoms fell from 3.8 to 1.5. In the traditional therapy group the mean value of subjective tinnitus decreased from 3.7 to 3.1. Objectively, 16 patients (80%) in the enoxaparin group showed improvement in auditory function. Mean value of hearing improved for those patients from 19.5 to 23.6 dB across the 2,000 to 4,000 Hz range.
The second study 2 was published in 2004 and was focused on autoimmune mediated sensorineural hearing loss, which is characterized as rapidly progressing hearing loss that has no known cause.
A man presented with a 6 month history of progressive sensorineural hearing loss in the right ear. He made reference to having systemic lupus erythematosus and was being treated with the standard medical therapy. There was no other apparent cause of his hearing loss. He was affected by a hearing loss of 30 dB in the range of 2,000 to 4,000 Hz. After treatment with enoxaparin, he recovered more than 25 dB hearing in the affected ear.
Encouraged by the result, the researchers embarked on a small study of 8 patients who suffered from unilateral progressive hearing loss and tinnitus for at least 6 months. The inclusion criteria were almost the same as the previous study; 30 dB hearing loss in the 2,000 to 4,000 Hz range. The exceptional criterion was that all patients suffered from lupus, which was thought to be the cause of the hearing loss. The patients were divided into two groups, an active and a placebo group, and admitted to the hospital for 10 days.
On discharge, the active group had a decrease in the mean score of subjective tinnitus from 3.1 to 1.5 while the placebo group decreased from 3.2 to 2.9. Hearing improved in 3 (75%) patients in the active group averaging 17.9 to 22.7 dB across the 2,000 to 4,000 Hz range.
These two studies were very small and larger studies are required before definitive results can be finalized. Nonetheless, the results are very encouraging for tinnitus patients who have reduced circulation due to thrombosis or embolism.
It should be pointed out that all the patients in these studies had hearing loss and tinnitus in the mid range (2,000 to 4,000 Hz) and not in higher frequencies. It is likely they have not suffered from cochlear hair cell damage, commonly caused by noise exposure or ototoxicity, which typically results in a high frequency hearing loss spreading to the lower frequencies as it progresses.
It is also important to note that Ginkgo biloba has a similar effect on micro-thrombosis and micro-embolism. In one study, 24 patients hospitalized with a form of dementia due to occluded cerebral arteries were treated with Ginkgo biloba extract or placebo for 12 weeks. The Ginkgo biloba extract-treated patients were found to be significantly superior in all measures, including EEG findings, reaction time and concentration. Using the venous micro-embolic index (VMI), a measure of platelet aggregation, the researchers found that platelet aggregation declined progressively in the treated patients from a high of 3.6 at baseline to 1.3 at week 12. There was no change in VMI in the placebo group. 3
Sodium enoxaparin shows promise for the treatment of tinnitus caused by micro-thrombosis and micro-embolism. Arches Tinnitus Relief Formula® contains the highest quality Ginkgo biloba extract found on the world market and exhibits many of the same properties and has the advantage of being non-prescription. These two products should not be combined except with the approval and monitoring by the prescribing physician. They are additive and blood thinning can be excessive, resulting in bleeding problems.
Author’s Note: The research materials for this article were graciously provided by Charles Smithdeal, MD, FACS, C.Ht.. Dr. Smithdeal is a board certified Otolaryngologist and Hypnotherapist and is the Director of the Hypnotherapy and Tinnitus Institute in St. Petersburg, FL. He has contributed two prior articles to Quiet Times that can be seen in our Tinnitus Information Center, Hypnotherapy & Tinnitus and Relaxation Techniques to reduce Tinnitus
- International Tinnitus Journal, Vol. 9, No. 2, 2003. The Use of Sodium Enoxaparin in the Treatment of Tinnitus. Mora R, Salami A, Barbieri M, Mora F, Passal GC, Capobianco S, Magnan J.
- Acta Orolaryngol 2004; Suppl 552: 25-28; Restoration of Immune-mediated Sensorineural Hearing Loss with Sodium Enoxaparin: A Case Report. More R, Mora F, Passali FM, Cordone MP, Crippa B, Barbieri M.
- Hofferberth B. Simultanerfassung elektrophysiologischer, psychometrischer und rheologischer Parameter bei Patienten mit hirnorganischem Psychosyndrom und erhöhtem Gerfässrisko Ð Eine Placebo-kontrollierte Doppleblindstudie mit Ginkgo biloba-Extrakt EGB 761. Stodtmeister R, Pillunat L, eds. Mikrozirkulation in Gehirn und Sinnesor-ganen. Stuttgart: Ferdinand Enke; 1991:64-74.