Tinnitus as a symptom

Pulsatile tinnitus is sometimes caused by a condition called ‘sigmoid sinus wall dehiscence’, in which there is an unwanted opening within the sinuses. Chinese surgeons [1] who had performed corrective surgery on 27 patients sought to determine whether this had improved their tinnitus. Two years after surgery, 14 patients said they had ‘complete resolution’, five had partial resolution, seven experienced no change and for one patient the tinnitus had worsened. This is a small study without a control group which does not use any of the standard scoring systems for measuring tinnitus. It is nevertheless of interest for people with tinnitus due to this condition.

Another surgical procedure was investigated for its impact on pulsatile tinnitus by a US team [2]. Surgeons treated 37 patients for a narrowing (stenosis) of the blood vessels called the venous sinuses (which drain blood from the brain), which had caused them to have ‘idiopathic intracranial hypertension’ (IIH). They fitted each patient with a ‘stent’ to widen the blood vessel. Of the 37 patients, 29 had pulsatile tinnitus, which is common in people with IIH. The 29 pulsatile tinnitus patients were given THI questionnaires to evaluate their tinnitus before and immediately after the treatment. With just one exception they all reported a major improvement and their tinnitus was considered to be resolved. The patients were followed up for two years and the improvement was maintained, except for three in whom the stenosis had in the meantime reappeared.

Otosclerosis is an abnormal growth of bone near the middle ear; most patients with the condition have tinnitus; many also have hearing loss. Turkish surgeons [3] used a technique known as ‘stapedotomy’ with 56 otosclerosis patients who had tinnitus, in an attempt to correct the condition and to see whether this also had an impact on their tinnitus. There was no control group and they did not use any of the accepted tinnitus scales – instead they asked patients to state whether their tinnitus was unchanged or had improved. Sixty-one per cent said they experienced an improvement after the surgery; patients with tinnitus of a low pitch were more likely to improve. Strangely the level of surgical success (assessed by the change in the ‘air-bone gap’) was not statistically related to the level of improvement in tinnitus.

People with the genetic condition neurofibromatosis experience a growth of ‘benign’ tumours along the nerves. Tinnitus is a very common symptom for these people. Sometimes it is necessary to remove some of these tumours surgically. When this has been done patients may be given an auditory brainstem implant (ABI), which is a similar device to a cochlear implant. In a so-called retrospective study, US researchers [4] asked 43 such patients whether their ABIs (which they can switch on and off) helped their tinnitus. Their average tinnitus levels were reduced.

Education and training

Education and training programmes of one sort or another may offer a way forward for many people with tinnitus. A Dutch team [5] have developed and evaluated one such programme, known as ‘neuropsychological education’. This programme involves two 90-minute training sessions in which theories as to the cause of tinnitus are presented, and then some suggestions for self-help interventions are given. The researchers asked the question whether providing this training soon after a patient’s tinnitus has first appeared might be effective and might make it unnecessary to provide any other form of treatment. One hundred and six new tinnitus patients received the training; 91 participated in the evaluation before the training, and at six weeks and at one year after. Fifty-four of these 91 said the training had been helpful. Only 59 of them decided to seek other treatments. Tinnitus handicap inventory scores were obtained for just 74 of the patients, but amongst those patients tinnitus was reduced at the six-week mark and further reduced after a year. The lack of a control group is just one of several drawbacks to this study but the programme, which requires little in the way of time or cost, would seem to deserve further investigation.

A publication called Games for Health Journal has published a study from New Zealand [6] in which a game called Terrain was developed specially for people with tinnitus. The developers say that 15 people who played Terrain showed reductions in their tinnitus levels compared with a control group who played an ordinary computer game. Unfortunately we do not have access to the full report of this study.

Pills

A small study from Iran [7] compared the use of two drugs for tinnitus treatment. One, betahistine, is widely used for Ménière’s disease and other balance disorders; the other, carbamazepine, has been studied for tinnitus many times before but with mixed results. Over 12 weeks, 75 patients were given either betahistine or carbamazepine or a placebo pill. There was no change in the tinnitus handicap scores of the placebo or betahistine patients but the carbamazepine patients showed a significant improvement. The report of this study is lacking in many respects and it may not have been well conducted.

Only outline details are so far available of a Japanese study [8] using a drug called Oligonol, derived from the lychee fruit, which is said to improve blood flow. The researchers suggest that blood flow and temperature around the ear auricle might cause tinnitus. An unknown number of patients received the drug and were compared with a control group. Using one of the standard scales used in tinnitus research, it appears that the treatment group experienced benefits from the drug. Obviously, more information is needed.

Zinc is known to play a role in the functioning of the ear and some individual studies have suggested that zinc supplements might help tinnitus. What is always needed, however, is a careful consideration of all good quality research on a subject like this before conclusions can be drawn. A Cochrane systematic review of studies using zinc supplementation to treat tinnitus [9] 55 has now been completed. The reviewers confined their analysis to randomised clinical trials (RCT) and they found only three RCTs (with just over 200 patients) have so far been conducted. The reviewers wanted to focus on studies that used a recognised (validated) scale for tinnitus but only one of the studies had done this. This study found that 5% of patients given zinc showed benefit, compared with 2% of the control group who also improved. The studies that used non-validated measures of tinnitus also found no significant differences between treatment and control groups. It seems therefore that there is no evidence to support the use of zinc in tinnitus treatment. However, as Cochrane reviewers often say, ‘Absence of evidence is not evidence of absence’; when very little research has yet been done on a treatment, we cannot conclude that it is ineffective. It is always possible that further research may produce a more definitive answer.

Plans for two more Cochrane reviews of potential tinnitus treatments – acupuncture and glutamate receptor antagonists (a category of drugs) – have recently been announced. The findings will be awaited with interest.

Focus on sound

Sound generators have helped some people with tinnitus and new types of generator are under development. One developed at the University of Nottingham has recently undergone a feasibility study [10] and in the light of the encouraging results full clinical trials are now planned.

Hearing aids are known to help many people with tinnitus, particularly those with some hearing loss. A small Brazilian study [11] of 17 patients supports this. Using questionnaires, before and three months after fitting these patients with hearing aids, the researchers found that the level of the tinnitus itself and the ‘emotional aspects’ of the condition had undergone significant improvement.

Brain stimulation

Studies continue with attempts to cure tinnitus with electrical or magnetic devices that stimulate the brain. One such treatment is transcranial direct current stimulation (tDCS). An international team [12] compared the effects of tDCS delivered to just one part of the brain with a new ‘multi-site’ approach. 40 patients were randomly selected for one or the other of these treatments, or to be in a control group scheduled to have treatment later. At the end of four weeks of treatment (on all the three questionnaire-based scoring systems used) there were no significant changes before and after treatment in the control or standard tDCS groups. However, significant improvement was found using the multi-site treatment. Despite several limitations in this small study and the lack of any follow-up checks, this is an interesting result.

Meanwhile, a German group [13] are in the early stage of investigating the combination of tDCS with ‘auditory stimulation’. In other words, participants watched TV while they were receiving tDCS, with the goal of distracting them from the stimulation. Having done a pilot study with 14 patients they are intending to continue their investigations.

Polish scientists [14] are looking at electrical stimulation of the ear itself. Working with 12 patients they have showed this approach can produce changes in electrical activity in the brain but so far they have not achieved any impact on tinnitus.

In your genes?

And finally could studies on genetics lead in time to new treatments for tinnitus? More and more is being learned about the human genome but so far nothing is known as to whether tinnitus might be, at least in part, ‘in the genes’. In a discussion paper [15], Spanish scientists argue that, as tinnitus is a symptom in several conditions that are known to be influenced by genetics, it would be worthwhile ‘to investigate the genetic underpinnings of tinnitus’. They propose a strategy for beginning such research.

References

Links are provided where possible to an abstract or full paper for your convenience.

1.     Zeng R, Wang G-P, Liu Z-H et al. Sigmoid sinus wall reconstruction for pulsatile tinnitus caused by sigmoid sinus wall dehiscence: a single-center experience. PLoS ONE 2016; 11:e0164728. 

2.     Boddu S, Dinkin M, Suurna M et al. Resolution of pulsatile tinnitus after venous sinus stenting in patients with idiopathic intracranial hypertension. PLoS ONE 2016; 11:e0164466.

3.     Ismi O, Erdogan O, Yesilova M et al. Does stapes surgery improve tinnitus in patients with otosclerosis? Braz J  Otorhinolaryngol 2016: S1808-8694(16)30143-4.

4.     Roberts DS, Otto S, Chen B. Tinnitus suppression after auditory brainstem implantation in patients with neurofibromatosis type-2. Otol Neurotol 2017; 38:118-122.

5.     Wagenaar OVG, Wieringa M, Mantingh L. Preliminary longitudinal results of neuropsychological education as first and sole intervention for new tinnitus patients. International Tinnitus Journal. 2016; 20:11-17

6.     Wise K, Kobayashi K, Magnusson J, Welch D, Searchfield G. Randomized controlled trial of a perceptual training game for tinnitus therapy. Games for Health Journal 2016; 5:141-149

7.     Mashali L, Rahimi S, Rekabi H, Rahimi P. The comparative study of two drugs of carbamazepine and betahistine on tinnitus improvement. International Journal of Pharmacy & Technology 2016; 8:14774-14781.

8.     Maeda T, Takanari J,  Fukuchi Y et al. Investigation of the amelioration effects of Oligonol® on tinnitus in randomized double-blinded placebo-controlled trial. Japanese Pharmacology and Therapeutics 2016; 44: 1329-1336.

9.     Person OC, Puga ME, da Silva EM, Torloni MR. Zinc supplementation for tinnitus. Cochrane Database Syst Rev. 2016;11:CD009832.

10.  Sereda M, Davies J, Hall DA. Pre-market version of a commercially available hearing instrument with a tinnitus sound generator: feasibility of evaluation in a clinical trial. International Journal Of Audiology 2016; 25 Nov.

11.  Cabral J, Tonocchi R, Ribas A. The efficacy of hearing aids for emotional and auditory tinnitus issues. International Tinnitus Journal 2016; 20:54-58.

12.  Wing Ting T, Ost J, Hart J. The added value of auditory cortex transcranial random noise stimulation (tRNS) after bifrontal transcranial direct current stimulation (tDCS) for tinnitus. Journal of Neural Transmission 2017; 124: 79–88.

13.  Henin S, Fein D, Smouha E, Parra LC. The effects of compensatory auditory stimulation and high-definition transcranial direct current stimulation (HD-tDCS) on tinnitus perception – a randomized pilot study. PLoS ONE 2016; 11:e0166208

14.  Mielczarek M, Michalska J, PolatyƄska K, Olszewski J. An increase in alpha band frequency in resting state eeg after electrical stimulation of the ear in tinnitus patients—a pilot study. Front. Neurosci 2016; 6 Oct.

15.  Lopez-Escamez JA,  Bibas T,  Cima RFF et al. Genetics of tinnitus: An emerging area for molecular diagnosis and drug development. Frontiers in Neuroscience 2016; 10:377.