Evaluation of botulinum toxin A in treatment of tinnitus

Intermediate Cervical Plexus Block in the Management of Refractory Somatosensory Tinnitus Following Whiplash: Prospective Series in 30 Patients

OBJECTIVE

Whiplash-associated disorder comprises of a constellation of persistent symptoms after neck trauma. Tinnitus that develops postwhiplash is termed somatosensory tinnitus. The objective is to assess the role of intermediate cervical plexus block (iCPB) in patients with somatosensory tinnitus secondary to whiplash.

METHODS

Prospective service evaluation in adults with whiplash-associated disorder and concomitant somatosensory tinnitus. Patients underwent specialist otorhinolaryngology review before pain clinic referral. Patients were offered ultrasound-guided iCPB with steroids. Intensity of tinnitus was recorded on a numerical rating scale at baseline, 3 and 6 months posttreatment. Brief Pain Inventory Short Form and Hospital Anxiety Depression Scale questionnaires were also completed.

RESULTS

Over a 36-month period, 32 patients with refractory somatosensory tinnitus following whiplash were offered iCPB(s). Two patients refused because of needle phobia. iCPB(s) was performed in 30 patients as an outpatient procedure. One patient (1/30, 3.3%) was lost to follow-up. Twenty-three patients (23/30, 77%) reported clinically significant reduction in intensity of tinnitus at 3 months postprocedure. Nineteen patients (19/30, 63%) reported ongoing benefit at 6-month follow-up. Six patients failed to report any benefit (6/30, 20%).

CONCLUSION

The cervical plexus could play a significant role in the development of somatosensory tinnitus after whiplash. iCPB may have a role in the management of somatosensory tinnitus in this cohort.

Somatosensory Tinnitus: Recent Developments in Diagnosis and Treatment

Somatosensory tinnitus (ST) is a type of tinnitus where changes in somatosensory input from the head-neck area are one of the influencing factors of a patient's tinnitus. As there are often several influencing factors, identifying a clear somatosensory influence on an individual patient's tinnitus is often a challenge. Therefore, a decision tree using four clinical criteria has been proposed that can help diagnose ST with an accuracy of 82.2%, a sensitivity of 82.5%, and a specificity of 79%. Once correctly diagnosed, patients can be successfully treated using a musculoskeletal physical therapy treatment. This type of treatment can either be directed at cervical spine dysfunctions, temporomandibular disorders, or both and consists of a combination of counseling, exercises, and manual techniques to restore normal function of the cervical spine and temporomandibular area. Other techniques have been suggested but need further investigation in larger RCTs. In most cases, ST treatment shows a decrease in tinnitus severity or loudness, but in rare cases, total remission of the tinnitus is achieved.

Tinnitus Guidelines and Their Evidence Base

Evidence-based medicine (EBM) is generally accepted as the gold standard for high-quality medicine and, thus, for managing patients with tinnitus. EBM integrates the best available scientific information with clinical experience and patient values to guide decision-making about clinical management. To help health care providers and clinicians, the available evidence is commonly translated into medical or clinical guidelines based on a consensus. These involve a systematic review of the literature and meta-analytic aggregation of research findings followed by the formulation of clinical recommendations. However, this approach also has limitations, which include a lack of consideration of individual patient characteristics, the susceptibility of guideline recommendations to material and immaterial conflicts of interest of guideline authors and long latencies till new knowledge is implemented in guidelines. A further important aspect in interpreting the existing literature is that the absence of evidence is not evidence of absence. These circumstances could result in the decoupling of recommendations and their supporting evidence, which becomes evident when guidelines from different countries differ in their recommendations. This opinion paper will discuss how these weaknesses can be addressed in tinnitus.

Botulinum Toxin Treatment of Objective Tinnitus Because of Essential Palatal Tremor: A Systematic Review

INTRODUCTION

In contrast to subjective tinnitus, objective tinnitus can be heard by the examiner as well as by the patient. It can be triggered by, among many other etiologies, idiopathic muscular tremor in the soft palate, the essential palatal tremor (EPT). Many treatment modalities have been investigated, of which only Botulinum toxin (BT) injections have shown promising results.

GOAL

The aim of this study was to evaluate the effect of BT treatment on objective tinnitus due to EPT by a systematic review of the literature.

METHODS

In accordance with PRISMA guideline a systematic literature search in three databases was performed.

RESULTS

Twenty-two studies fulfilled the inclusion criteria, mainly case reports and case series. A total of 51 BT treated patients diagnosed with EPT were identified in the literature. The studies were evaluated with focus on diagnostics, injection technique and BT dose, follow-up, effect on objective tinnitus, complications, and adverse effects.

CONCLUSIONS

The included studies suffer from an extremely low evidence level with several sources of bias. When optimally injected, BT seems to be an effective treatment of objective tinnitus due to EPT, with few adverse effects and complications. We suggest BT injections as first choice in case of EPT and present a guideline regarding diagnostics, treatment, and follow-up.

Botulinum toxin treatment for essential palatal tremors presenting with nasal clicks instead of pulsatile tinnitus: a case report

Background

In this study, we report a rare case of an adult patient with essential palatal tremors (EPT) presenting as nasal clicks, instead of otic clicks or objective pulsatile tinnitus in common EPT.

Case presentation

Nasal endoscopic examination and EMG recordings of the soft palate muscles were performed to confirm the source of the clicks. Initial treatment with lidocaine provided symptomatic relief for four hours. The patient was then treated with four simultaneous injections of 12.5 U of botulinum toxin in four different sites of the soft palate. Palatal tremors and clicks completely disappeared within three months of treatment.

Conclusions

To our knowledge, this is the first case of EPT that presented with nasal clicks. We recommend that otolaryngologists should expect this rare occurrence in the clinical setting, and handle patients presenting with such symptoms with care and compassion in order not to worsen their psychological status.

Electronic supplementary material

The online version of this article (doi:10.1186/s13005-016-0129-6) contains supplementary material, which is available to authorized users.

A Systematic Review of Eligibility and Outcomes in Tinnitus Trials

Objective

To analyze existing tinnitus treatment trials with regard to eligibility criteria, outcome measures, study quality, and external validity and to recognize the effect of patient demographics, symptom duration, severity, and otologic comorbidity on research findings to help practitioners apply them to patient encounters.

Data Sources

Systematic literature search conducted by an information specialist for development of the American Academy of Otolaryngology—Head and Neck Surgery Foundation’s tinnitus clinical practice guideline.

Review Methods

Articles were assessed for eligibility with the PRISMA protocol (Preferred Reporting Items for Systematic Reviews and Meta-analyses) and data extracted by 2 independent investigators. Studies were assessed for methodological quality, inclusion and exclusion criteria, patient demographics, and outcome measures.

Results

A total of 147 randomized trials met inclusion criteria. Nearly all studies took place in a specialist setting. More than 50% did not explicitly define tinnitus, and 44% used a subjective severity threshold, such as “severely disturbing.” Fifty-four percent required symptom duration of at least 6 months for study eligibility, and up to 33% excluded patients with “organic” hearing loss or otologic conditions. Mean age was 52.2 years, and median follow-up was 3 months. Only 20% had a low risk of bias.

Conclusion

Randomized trials of tinnitus interventions are most applicable to older adults with tinnitus lasting ≥6 months who are evaluated in specialty settings. High risk of bias, short follow-up, and outcome reporting raise concerns about the validity of findings and may influence how clinicians apply trial results to individual patients and establish treatment expectations, thus demonstrating the need for further quality research in this field.

Cervical epidural steroid injection for refractory somatic tinnitus

Somatic tinnitus is a common disorder, yet few treatments described in the literature have demonstrated strong efficacy. We report a case of a 61-year-old male with refractory somatic tinnitus, temporally related to a prior bacterial otitis media, wherein auditory symptoms were successfully treated with cervical epidural injections of long-acting corticosteroid. We discuss the proposed mechanism of somatic tinnitus and the means by which neuraxial steroids may inhibit somatic tinnitus symptoms.

'Is tinnitus accompanied by hemifacial spasm in normal-hearing patients also a type of hyperactive neurovascular compression syndrome? : A magnetoencephalography study

Background

Traditionally, tinnitus accompanied by hemifacial spasm has been considered a type of hyperactive neurovascular compression syndrome that is similar to hemifacial spasm alone because of the anatomically close relationship between the facial nerve and cochlear nerve as well as the hyperactive clinical nature.

Methods

Participants were 29 subjects who presented with hemifacial spasm and neuroradiological evidence of vascular compression of the cranial (facial/cochlear) nerve. We used magnetoencephalography (MEG) to estimate the activity of the cochlear nerve in patients with and without tinnitus on the ipsilateral side. We compared the difference in the latency and the ratio of the equivalent current dipole (ECD) strength between the ipsilateral and contralateral sides of the spasm and tinnitus.

Results

Cochlear nerve activity in patients with tinnitus was increased with a shorter latency (p = 0.016) and stronger ECD strength (p = 0.028) compared with patients without tinnitus.

Conclusion

The MEG results from normal-hearing patients who had tinnitus accompanied by hemifacial spasm suggest that the hyperactivity of the auditory central nervous system may be a crucial pathophysiological factor in the generation of tinnitus in these patients. The neurovascular compression that causes sensory input from the pathologic facial nerve activity may contribute to this hyperactivity of the central auditory nervous system.

Objective tinnitus from palatal myoclonus. Use of botulinum toxin: a case report

Objective tinnitus can have many different etiologies, palatal myoclonus being one of the less frequent. This type of tinnitus is generated by involuntary rhythmic contraction of the soft palate, which generates an audible click for the patient and for the explorer. Botulinum toxin achieves temporary muscle paralysis through presynaptic inhibition of the acetylcholine level at the neuromuscular union. We present a patient with long-term objective tinnitus, along with this patient's response to botulinum toxin injection.

Diagnosis and management of somatosensory tinnitus: review article

Tinnitus is the perception of sound in the absence of an acoustic external stimulus. It affects 10-17% of the world's population and it a complex symptom with multiple causes, which is influenced by pathways other than the auditory one. Recently, it has been observed that tinnitus may be provoked or modulated by stimulation arising from the somatosensorial system, as well as from the somatomotor and visual-motor systems. This specific subgroup -somatosensory tinnitus - is present in 65% of cases, even though it tends to be underdiagnosed. As a consequence, it is necessary to establish evaluation protocols and specific treatments focusing on both the auditory pathway and the musculoskeletal system.

Emerging pharmacotherapy of tinnitus

Tinnitus, the perception of sound in the absence of an auditory stimulus, is perceived by about 1 in 10 adults, and for at least 1 in 100, tinnitus severely affects their quality of life. Because tinnitus is frequently associated with irritability, agitation, stress, insomnia, anxiety and depression, the social and economic burdens of tinnitus can be enormous. No curative treatments are available. However, tinnitus symptoms can be alleviated to some extent. The most widespread management therapies consist of auditory stimulation and cognitive behavioral treatment, aiming at improving habituation and coping strategies. Available clinical trials vary in methodological rigor and have been performed for a considerable number of different drugs. None of the investigated drugs have demonstrated providing replicable long-term reduction of tinnitus impact in the majority of patients in excess of placebo effects. Accordingly, there are no FDA or European Medicines Agency approved drugs for the treatment of tinnitus. However, in spite of the lack of evidence, a large variety of different compounds are prescribed off-label. Therefore, more effective pharmacotherapies for this huge and still growing market are desperately needed and even a drug that produces only a small but significant effect would have an enormous therapeutic impact. This review describes current and emerging pharmacotherapies with current difficulties and limitations. In addition, it provides an estimate of the tinnitus market. Finally, it describes recent advances in the tinnitus field which may help overcome obstacles faced in the pharmacological treatment of tinnitus. These include incomplete knowledge of tinnitus pathophysiology, lack of well-established animal models, heterogeneity of different forms of tinnitus, difficulties in tinnitus assessment and outcome measurement and variability in clinical trial methodology.

The use of botulinum toxin in head and face medicine: an interdisciplinary field

Background

In this review article different interdisciplinary relevant applications of botulinum toxin type A (BTA) in the head and face region are demonstrated.

Patients with head and face disorders of different etiology often suffer from disorders concerning their musculature (example: synkinesis in mimic muscles) or gland-secretion.

This leads to many problems and reduces their quality of life. The application of BTA can improve movement disorders like blepharospasm, hemifacial spasm, synkinesis following defective healing of the facial nerve, palatal tremor, severe bruxism, oromandibular dystonias hypertrophy of the masseter muscle and disorders of the autonomous nerve system like hypersalivation, hyperlacrimation, pathological sweating and intrinsic rhinitis.

Conclusion

The application of botulinum toxin type A is a helpful and minimally invasive treatment option to improve the quality of life in patients with head and face disorders of different quality and etiology. Side effects are rare.

Sympathetic skin responses from postauricular region in Meniere’s disease

OBJECTIVE

To investigate the sympathetic nervous system activity in Meniere's disease (MD) by recording sympathetic skin responses (SSRs) from the postauricular region (PA).

METHODS

Twenty-one patients with definite unilateral MD diagnosis and 12 healthy volunteers were studied by evoking right and left PA-SSRs with electrical stimulation of the left median nerve at the wrist in attack and interval periods of MD. Mean latencies and maximum amplitudes were used in statistical analyses.

RESULTS

In unilateral definite MD patients, the mean latencies were longer and the maximum amplitudes were smaller on the involved ear side than those on the normal ear side (p<0.01 for both amplitude and latency) and than those from the controls (p<0.01 and p<0.05). In three patients, there was no detectable PA-SSR on the involved ear side while there were SSRs on the healthy side. In four patients, the responses were absent bilaterally during the attack period.

CONCLUSIONS

There is a marked asymmetric sympathetic hypofunction in the area of the PA region of the involved ear in MD patients.

SIGNIFICANCE

The PA region is a new site for recording sympathetic skin responses. PA-SSR is a useful tool to investigate sympathetic nervous system function in MD patients.

Intratympanic application of botulinum toxin: experiments in guinea pigs for excluding ototoxic effects

The aim of the study was to exclude ototoxic side effects of intratympanally applied botulinum toxin. The background is that a transection of the tensor tympani tendon (tenotomy) may relieve symptoms of tinnitus due to myoclonic tensor contractions. Moreover, there are certain indications that in some cases tenotomy may influence the course of Menière's disease positively. In such cases, a temporary (probatory) inactivation of the muscle with botulinum toxin might be better than a definitive surgical solution. Although in theory botulinum toxin should not have ototoxic side effects, a study on animals (guinea pigs) should prove this assumption. On eight guinea pigs (16 ears), the middle ear spaces (bullae) were opened and botulinum toxin was introduced. Hearing thresholds were measured via ABR recordings, prior to 1 and 3 weeks, respectively, after botulinum toxin application. Histological examinations of the middle ear mucosa were performed on each animal. In our series, the hearing thresholds remained essentially unchanged. Furthermore, no middle ear pathologies could be found in histology. No negative effects of botulinum toxin on hearing could be observed in our series. This is a precondition for the further development of the concept of intratympanical applications of the drug, to inactivate the tensor tympani muscle or for other options.

[Botulinum toxin treatment in the head and neck region: current aspects, developments, and problems]

Some interesting developments, aspects, and problems concerning botulinum toxin treatment of disorders of the head and neck region have recently been reported. These new approaches are discussed in this review. They include applications into mimic muscles (prevention of scar formation, treatment of depressions), into laryngeal muscles, and into the upper esophagus. In addition, treatment of different forms of headache and tinnitus as well as applications in the autonomic nervous system are addressed. Some of these options will shortly be put into clinical use, while others have to be checked further in clinical studies.