Effective in the treatment of central tinnitus: Ginkgo special extract EGb 761® increases neuronal plasticity

Retraining therapy: EGb 761 ^® can help to “unlearn” tinnitus / animal model demonstrates protective effect against tinnitus

Around three million Germans permanently suffer from tinnitus, which can cause some considerable impairment in daily life. According to the most recent research findings, tinnitus results from maladaptive learning processes. The pharmacological reinforcement of neuronal plasticity to promote “unlearning” is therefore a new therapeutic approach. Ginkgo special extract EGb 761 ^® (Tebonin ^® ) is suitable for this, as studies show that it increases neuronal plasticity. ¹ At the ENT Congress in Mainz, experts described the current status of research during a satellite symposium organised by Dr. Willmar Schwabe and chaired by Prof. Norbert Holstein, Karlsruhe. ² His conclusion: “The clinical data show that EGb 761 ^® is an effective and well-tolerated option to help in the treatment of various forms of tinnitus.” In an animal model, a protective effect against the development of central tinnitus was found with EGb 761 ^® . ³

The pathogenesis of acute tinnitus was long thought to be of vascular origin. However, research over the past few years shows that tinnitus can be described as “phantom pain” of the inner ear. “Tinnitus arises as a central phenomenon with a predominantly peripheral trigger – hearing loss – based on maladaptive learning processes in the auditory cortex”, explained Prof. Christo Pantev, Münster. The maladaptive neuronal plasticity leads to the formation of a cortical tinnitus network – tinnitus is “learnt” and can therefore also be “unlearnt”. According to Prof. Holger Schulze, University of Erlangen-Nuremberg, so-called retraining therapies have been shown to be particularly promising for the treatment of central tinnitus. The aim is to reverse the neuroplastic changes underlying the tinnitus. “Studies suggest that EGb 761^® can further support specific retraining programmes by promoting the renewed neuroplastic development” according to Schulze.

Effects of EGb 761 ^® on facilitation of learning

The facilitating effects of Ginkgo special extract on learning could be shown in animal models using auditory discrimination learning, as Schulze demonstrated: Over 15 days, Mongolian gerbils learnt to discriminate between different tones. The animals were given EGb 761^® or placebo every day two weeks before and during training. “The animals treated with EGb 761^® learnt much faster than the control group”, according to Schulze. The constituents in EGb 761^® promote neuronal plasticity by increasing neurite proliferation and synapse formation. Owing to the neuroprotective properties, the special extract can also protect the sensory cells of the cochlea from damage.

Protective effect against tinnitus

A protective effect of EGb 761^® against acoustic trauma was also demonstrated in an animal model.³ This consequently led to protection against the development of central tinnitus, according to Schulze: “This protective effect is probably based on an increased recruitment of global inhibition in the auditory cortex of the animals treated with EGb 761^® .” Mongolian gerbils were given EGb 761^® or placebo every day from 12 to 43 days before and up to 14 days after being exposed to acoustic trauma. Result: The animals treated with EGb^® 761 had slightly improved auditory thresholds even before acoustic trauma and a clearly lower auditory threshold loss overall after acoustic trauma. Of the gerbils treated, only 34 percent developed tinnitus after the acoustic trauma, in the control group it was 83 percent.

EGb 761 ^® effective for several forms of tinnitus

Apart from improving circulation, EGb 761^® primarily has neuroprotective properties, protects energy generation in neuronal mitochondria and promotes dopaminergic neurotransmission and neuroplasticity, as Schulze explained. Dieter Schneider, assistant professor at the University of Wurzburg, presented data on the therapeutic benefits of EGb 761^® in tinnitus from a recent review with eight placebo-controlled studies and a total of 1,199 patients:⁴ “In all studies, EGb 761^® was better than placebo.” In particular, the Ginkgo special extract was shown to be effective against very different forms of tinnitus: Acute to subchronic or chronic tinnitus, cerebrovascular insufficiency with concomitant tinnitus and dementia with concomitant tinnitus. In the studies, EGb 761^® was well tolerated and the rate of adverse events was at the placebo level. Schneider remarked that “Different Ginkgo extracts can differ considerably owing to different manufacturing processes.” The positive study data on EGb 761^® therefore cannot simply be transferred to other preparations. Vice versa, the studies with other Ginkgo preparations that were not able to demonstrate any effects do not call the results presented here into question.

Combination therapy for an intractable clinical picture

Chronic tinnitus is a challenge for the therapist, as every individual measure can only have a limited effect. For this reason, multimodal treatment concepts have become established in practice over the past few years, as explained by Prof. Holstein. Based on the new neurobiological findings, which have identified learning processes as an important element for tinnitus therapy, it appears appropriate to complement this approach with EGb 761^® in order to promote neuroplasticity and thus to facilitate the “unlearning” of tinnitus.

About Tebonin ^®

Tebonin^® intens 120 mg (high-dose patented EGb 761^® Ginkgo biloba extract) is approved for adjuvant therapy of tinnitus of vascular and involutional origin. The recommended daily dose is 120 to 240 mg, corresponding to one or two film-coated tablets of Tebonin^® intens.

Tebonin^® contains Ginkgo biloba special extract EGb 761^® as active ingredient, standardised by means of an additional patented extraction stage during manufacture to 22.0 – 27.0 % Ginkgo flavone glycosides and 5.0 – 7.0 % terpene lactones. For more than 20 years, the action, efficacy and tolerability of EGb 761^® has been systematically investigated, so that today EGb 761^® is the best researched and documented plant extract worldwide.

Dr. Willmar Schwabe

Over the 140 years since being founded, the Dr. Willmar Schwabe company has reached a leading position worldwide in the development and manufacture of phytopharmaceuticals. The high quality of our herbal medicines and dietary supplements and the scientific documentation of our special extracts are the reasons why Schwabe enjoys the reputation of being the “specialist for phytopharmaceuticals”. www.schwabepharma.com

Sources:

1) Tchantchou et al. Journal of Alzheimer`s Disease, 2009

2) Symposium „Tinnitus – ‚Phantomschmerz‘ der Cochlea. Moderne Konzepte zu Tinnitusentstehung und -therapie“, veranstaltet von Dr. Willmar Schwabe am 17. Mai 2012 in Mainz anlässlich der 83. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohrenheilkunde, Kopf- und Halschirurgie e.V.

3) Schulze H. et al.: Med Review 2011,11:5

4) Von Boetticher A.: Neuropsychiatric Disease and Treatment 2011:7,441-447

Contact:

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Judith Elbert
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Judith.Elbert@schwabe.de
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