New article by Jan Tunér
Somatosensory tinnitus vademecum
- Low
level laser therapy of tinnitus - a case for the dentist?
Welcome to TLC - Tinnitus Laser CentreTLC is a Swedish non-profit association with the aim of promoting
the knowledge about Laser Therapy of tinnitus. Tinnitus is a very
seriuos, debilitating and widespread phenomenon. Medicine has so far
tried many therapies and they seem to have only one trait in common
- they are not very successful. Laser therapy is not yet an established
therapy for tinnitus, but taking the positive anecdotal reports into
account, coupled with a number of positive clinical studies, we feel
this is an area well worth of further exploration.
For no 1 there is no therapy known to us Therapy Witt [3] is one of the pioneers in this field, but to the knowledge
of the author his results have not been published in any peer-review
journal. Witt combines infusion of Gingko biloba (Egb 761, 17.5 mg
dry extract per 5 ml amouple)) and laser. This may be a favourable
combination but an evaluation of the contribution of the laser is
not possible. More than 500 patients have been treated since 1989
and Witt claims that more than 60% of the patients have reached a
considerable or total relief . The laser used is a combination of
HeNe 12 mW/GaAs 5 x 10 mW. Treatment technique not stated. Swoboda [4] did not find any significant effect of Gingo/laser. However, the ginkgo infusion used was at a homeopathic level (D3 = 1:1000 dilution), acc. to Witt. Partheniadis-Stumpf [5] also failed to find any effect from the combined ginkgo (6 ml Tebonin) infusion and laser. However, the laser was applied at a distance of one cm above the mastoid. The non-contact mode reduces penetration considerably and the mastoid is not ideal for reaching the inner ear. Plath [6] treated 40 tinnitus patients with 50 mg Ginkgo biloba. 20 patients received sham laser irradiation, 20 real laser. A HeNe 12 mW/GaAs 5 x 15 mW GaAs laser was used, irradiation procedure approximately the same as for Partheniadis-Stumpf. In this study, 50% of the patients reported a reduction of the tinnitus of more than 10 dB, compared with 5% in the control group, in both self-assessment and audiometric findings. A similar study has been performed by von Wedel [7]. 155 patients were treated with Ginkgo infusion (5 ml Syxyl D3) and laser. The outcome was negative. No information about the type of laser, treatment technique or dosage is given, making an evaluation impossible. Shiomi [8] has investigated the effect of infrared laser applied directly into the meatus acusticus, 21 J, once a week for 10 weeks. The result of this non-controlled study is as follows: 26% of the patients reported improved duration, 58% reduced loudness and 55% reported a general reduction in annoyance. The same author [9] has also examined the effect of light on the cochlea, using guinea pigs. Direct laser irradiation was administred to the cochlea through the round window and the amplitude of CAP was reduced to 53-83% immediately after the onset of irradiation. The amplitude then returned to the original level. The results of this investigation suggest that LLLT might lessen tinnitus by suppressing the abnormal excitation of the 8th nerve or the organ of Corti. More or less the same parameters were used in a controled study by Mirtz [10] but in this case there was no significant effect. Wilden [11] [12] has applied a different method where the dose has been increased considerably. A set consisting of one HeNe laser and three powerful GaAlAs lasers is used, covering a large area over and around the ear, in the non-contact mode. Doses between 3.000 and 5.000 J are given each session. Laser is applied as a monotherapy. More than 800 patients have been treated with this concept and positive effects are reported, even for vertigo. Recent injuries in "the disco generation" are more easily treated than long-term chronic conditions. In a separate study [13] Wilden reports improvment of the hearing capacity of these patients, as evaluated by audiometry. Beyer [14] has performed a very exact ex-vivo laser penetration study. Based on these findings it was possible to calculate the energy needed to obtain a dose of 4 J/cm2 in the cochlea itself. 30 patient were treated five times within 2 weeks. One group was irradiated with 635 nm diode laser, the other with 830 nm diode laser. By self-assessment around 40% of the patients reported a slight to significant attenuation of the tinnitus loudness of the irradiated ear. This study has been followed by a double blind study. Prochazka [15] has evaluated the effect of combined Egb 761 Ginkgo infusion and laser in a double blind study. 37 patients were divided into three groups. One group had Egb 761 only, one Egb761 and placebo laser, one Egb761 and real laser, 830 nm. The results in the three groups were as follows: no effect 29/26/19, less than 50% relief 44/48/29, more than 50% relief 18/26/36, no more tinnitus 9/0/26. Irradiation was performed over the mastoid and over the meatus acusticus, twice a week, 8-10 sessions, total 175 J. Rogowski [16] divided a group of 32 tinnitus patients into one group receiving LLLT and one receiving a placebo procedure. Dose, wavelength and treatment technique not stated in the available English abstract. The effect was evaluated through VAS. Within the patient group transiently evoked otoacoustic emissions (TEOAE) were measured before, during and after therapy. No significant difference between laser and placebo was found in annoyance or loudness of the tinnitus and in changes of TEOAE amplitude. These results indicate that there is no relationship between the effect of low-power laser and changes in cochlear micromechanics. A few other indications in otorhinolaryngology have been treated with low level lasers, even with intravenous irradiation. [17-20] It is obvious that the available literature on laser therapy of tinnitus is scarse and ambiguous. Some studies have used a combination of Ginkgo and laser, others laser as monotherapy. Differences in wavelengths, pulsing, dosage and treatment technique makes a firm evaluation impossible. However, the positive results reported in some studies do merit attention and further research. Recent clinical experience also suggests that the doses necessary for successful outcome of the therapy have to be increased considerably. Tinnitus is a grave condition, sometimes leading to suicide. It is also an increasing problem and the existing treatment modalities offered to tinnitus patients are not very effective. Young persons suffering from acoustic chocks (concerts, discos) can be more successfully treated with laser therapy. Understandably enough, a long standing condition in elderly persons is a severe condition taking 10-20 sessions to influence. References: TLC research
Further research
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