Research Review By Dr. Brynne Stainsby©

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Date Posted:

July 2016

Study Title:

Cervicogenic somatosensory tinnitus: An indication for manual therapy? Part 1: Theoretical concept

Authors:

Oostendorp RAB, Bakker I, Elvers H et al.

Author's Affiliations:

Department of Manual Therapy, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium; Scientific Institute for Quality of Healthcare, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; Pain in Motion International Research Group, Vrije Universiteit Brussel, Brussels, Belgium; Practice for Manual Therapy, Arnhem, The Netherlands; Department of Public Health and Research, Radboud University Nijmegen Medical, The Netherlands; Institute for Methodology and Statistics Beuningen, The Netherlands; Department of Physiotherapy, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, Poland; Rehabilitation Clinic, Military Clinical Hospital No. 10 with Polyclinic in Bydgoszcz, Poland; Neurocognitive Laboratory, Center for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Torun, Poland; Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University of Antwerp, Belgium; Department of Otorhinolaryngology, Antwerp University Hospital, Belgium; Department of Medical Psychology, Radboud University Nijmegen Medical Centre, The Netherlands.

Publication Information:

Musculoskeletal Science & Practice 2016; 23: 120-123.

Background Information:

Tinnitus has been described as the perception of sound in the absence of an auditory stimulus (1). Given its subjective nature, it is very difficult to assess and often considered untreatable (2-6).

In the adult population, the prevalence of tinnitus has been reported to range from 7-19%, which seems to increase until 60-80 years of age (7). With respect to the impact on a patient’s life, up to 5% of the population report that tinnitus negatively interferes with their life, and 2% report a severe negative effect (8). Patients report problems with sleep, anxiety, depression, limitations in activity and decreased ability to work and participate in social activities (9, 10). In some patients, the negative impact can become so intense it can drive them to commit suicide (11).

This review is the first of a two-part project, with this part focusing specifically on the classification of tinnitus and outlining the anatomical relationship between the auditory and somatosensory systems. The second part will identify relevant components and outcomes of manual therapy in patients with cervicogenic somatosensory tinnitus.

Summary:

Classification of Tinnitus

Tinnitus can be described as objective (heard by both patient and clinician) or subjective (heard only by the patient) (2). Subjective tinnitus is more common, and can be subdivided into peripheral and central (2). Peripheral tinnitus is related to anatomical structures of the ear or the cervical spine and can be classified as conductive tinnitus (damage to outer or middle ear) or sensorineural tinnitus (damage to the inner ear or other structures). Sensorineural tinnitus can further be divided as follows:
  • Type I: Motor tinnitus – cochlear amplification in the outer hair cells
  • Type II: Transduction tinnitus – electromechanical transduction of the inner hair cells
  • Type III: Transformation tinnitus – issues with signal transfer from the inner hair cells and along the auditory nerve fibres
  • Type IV: Extrasensory tinnitus – causes outside of the auditory system (including cervicogenic)
Central tinnitus can be divided into primary (originating in the brain) or secondary. Secondary tinnitus begins with a peripheral trigger, however manifests in the brain.

Somatosensory Tinnitus

Somatosensory tinnitus is affected by inputs from the somatosensory and somatomotor systems. In cervicogenic tinnitus (CeT) specifically, tinnitus is related to the anatomical structures and physiological functions of the cervical region (6, 12-14). Given the anatomical relationship between the caudal aspect of the spinal nucleus of the trigeminal nerve and the spinal cord and peripheral nerves from C1-4, it is possible that convergence of information occurs. Signals that originate from the face and upper cervical spine integrate with input from the cochlea at the cochlear nuclei. Anatomical relationships also exist between the cervical spinal cord and the external and middle ear via the common spinal tract of the facial, glossopharyngeal and vagus nerves. Due to these connections, noxious activity in the somatosensory system can result in disinhibition of the dorsal cochlear nucleus, and therefore increased tinnitus. Specifically, the loudness and intensity of tinnitus is impacted by inputs such as muscular contraction, pressure applied to trigger points or joint movements (3, 4, 6, 12-15).

In some patients, chronic somatosensory tinnitus develops, often in conjunction with chronic musculoskeletal pain (16). In these patients, sensitization of the nervous system is the critical feature, specifically sensitivity to peripheral stimulation. Even in the absence of auditory stimuli, sound will be perceived as noxious by patients with chronic somatosensory tinnitus (17).

Treatment of Tinnitus:

In addition to medications (not discussed in this review), sound-based therapies and cognitive behavioural therapies (CBT) are the main treatment options for tinnitus (18, 20, 21). The efficacy of these interventions remains largely unknown (19), however it appears that CBT has the strongest evidence currently (22).

Little has been published to date regarding the effectiveness of manual therapy in the treatment of patients with tinnitus, however, an understanding of the cervicocranial anatomy and innervation of related structures will provide a rationale for a trial of therapy. Clinicians may attempt to stimulate the proprioceptors in a non-noxious way, such as using gentle, low velocity passive joint movements (mobilizations) and activating the craniocervical muscles through active care. Clinicians could also employ high-velocity, low-amplitude techniques (i.e. SMT) for the same reasons

Like patients with musculoskeletal pain, in patients with CeT, it is important to identify any specific musculoskeletal impairments identified on physical exam, and attempt to address these through treatment (14, 23-25). As always, information and education regarding the nature of the complaint, natural history, maintaining activity, and pain science comprise an important component in the treatment of patients with neck pain and CeT (16, 26).

Clinical Application & Conclusions:

This review has provided a theoretical framework for the development of somatosensory tinnitus, cervicogenic tinnitus (CeT) and chronic somatosensory tinnitus, and the effects on a patient’s life when living with these conditions. The classification of tinnitus will help clinicians with the diagnosis of somatosensory and CeT.

The proposed underlying mechanism for the development of CeT will be studied in the authors’ future study, however the anatomical connection between the cervical somatosensory and auditory systems demonstrate a rationale for a trial of manual therapy in these patients.

Study Methods:

The methods used to conduct this study were not outlined in this paper, though it appears to be a brief narrative review of the available literature. It should be noted that little has been published regarding cervicogenic tinnitus to date, and the authors aimed to describe potential underlying mechanisms between the auditory and cervical somatosensory systems in this literature review.

Study Strengths / Weaknesses:

Strengths:
  • Anatomical relationships between the cervical somatosensory and auditory systems were identified in an attempt to create a theoretical framework for understanding the development of cervical tinnitus.
  • Subtypes of tinnitus were outlined.
  • Current therapeutic options of sound-based therapies and cognitive behavioural therapies were described.
  • Based on the theoretical framework described, the authors provided suggested options for manual therapy.
Weaknesses:
  • The primary limitation of this study was the lack of described methodology. Though it provided a brief summary of the literature, without an understanding of the research question, search strategy or appraisal methods used, the results must be interpreted with a great degree of caution.
  • The sample sizes, characteristics or strengths and weaknesses of the included studies were not described.
  • Given the lack of described methodology, it is difficult to determine how the literature search was conducted and if all possible mechanisms have been outlined.

Additional References:

  1. Hoekstra CEM. A central nervous system approach to tinnitus. Utrecht: Universiteit Utrecht; 2013. Academic thesis.
  2. Zenner HP. A systematic classification of tinnitus generator mechanisms. Int Tinnitus J 1998; 4(2): 109-113.
  3. Shore S, Zhou J, Koehler S. Neural mechanisms underlying somatic tinnitus. Prog Brain Res 2007; 166: 107-123.
  4. Shore SE, Koehler S, Oldakowski M et al. Dorsal cochlear nucleus responses to somatosensory stimulation are enhanced after noise-induced hearing loss. Eur J Neurosci 2008; 27(1): 155-168.
  5. Baguley D, McFerran D, Hall D. Tinnitus. Lancet 2013; 382: 1600-1607.
  6. Levine RA, Nam EC, Oron Y et al. Evidence for a tinnitus subgroup responsive to somatosensory based treatment modalities. Prog Brain Res 2007; 166: 195-207.
  7. Henry JA, Dennis KC, Schechter MA. General review of tinnitus: prevalence, mechanisms, effects, and management. J Speech Lang Hear Res 2005; 48: 1204-1235.
  8. Nondahl DM, Cruickshanks KJ, Wiley TL et al. Prevalence and 5-year incidence of tinnitus among older adults: the epidemiology of hearing loss study. J Am Acad Audiol 2002; 13: 323-331.
  9. Zoger S, Svedlund J, Holgers KM. Relationship between tinnitus severity and psychiatric disorders. Psychosomatics 2006; 47: 282-288.
  10. Tyler RS, Baker LJ. Difficulties experienced by tinnitus sufferers. J Speech Hear Disord 1983; 48: 150-154.
  11. Pridmore S, Walter G, Friedland P. Tinnitus and suicide: recent cases on the public record give cause for reconsideration. Otolaryngol Head Neck Surg 2012; 147(2): 193-195.
  12. Levine RA. Somatic (craniocervical) tinnitus and the dorsal cochlear nucleus hypothesis. Am J Otolaryngol 1999; 20(6): 351-362.
  13. Sanchez TG, Bezerra Rocha CB. Diagnosis and management of somatosensory tinnitus: Review article. Clin (Sao Paulo) 2011; 66(6): 1089-1094.
  14. Levine RA, Oron Y. Tinnitus. Handb Clin Neurol 2015; 129: 409-431.
  15. Dehmel S, Pradhan S, Koehler S et al. Noise overexposure alters long-term somatosensory-auditory processing in the dorsal cochlear nucleus: Possible basis for tinnitus-related hyperactivity? J Neurosci 2012; 32(5): 1660-1671.
  16. Nijs J, Paul van Wilgen C, Van Oosterwijck J et al. How to explain central sensitization to patients with 'unexplained' chronic musculoskeletal pain: Practice guidelines. Man Ther 2011; 16(5): 413-418.
  17. Isaacson JE, Moyer MT, Schuler HG, Blackall GF. Clinical associations between tinnitus and chronic pain. Otolaryngol Head Neck Surg 2003; 128(5): 706-710.
  18. Phillips JS, McFerran D. Tinnitus retraining therapy (TRT) for tinnitus. Cochrane Database Syst Rev 2010;(3). http://dx.doi.org/10.1002/14651858.CD007330.pub2. Art. No.: CD007330.
  19. Hoare DJ, Kowalkowski VL, Kang S et al. Systematic review and meta-analyses of randomized controlled trials examining tinnitus management. Laryngoscope 2011; 121(7): 1555-1564.
  20. Hobson J, Chisholm E, El Refaie A. Sound therapy (masking) in the management of tinnitus in adults. Cochrane Database Syst Rev 2012;(11). http://dx.doi.org/10.1002/14651858.CD006371.pub3. Art. No.: CD006371.
  21. Martinez-Devesa P, Perera R, Theodoulou M, Waddell A. Cognitive behavioural therapy for tinnitus. Cochrane Database Syst Rev 2010;(9). http://dx.doi.org/10.1002/14651858.CD005233.pub3. Art. No.: CD005233.
  22. Cima RF, Andersson G, Schmidt CJ, Henry JA. Cognitive-behavioral treatments for tinnitus: a review of the literature. J Am Acad Audiol 2014; 25(1): 29-61.
  23. Zito G, Jull G, Story I. Clinical tests of musculoskeletal dysfunction in the diagnosis of cervicogenic headache. Man Ther 2006; 11(2): 118-129.
  24. Latifpour DH, Grenner J, Sjodahl C. The effect of a new treatment based on somatosensory stimulation in a group of patients with somatically-related tinnitus. Int Tinnitus J 2009; 15(1): 94-99.
  25. Michiels S, De Hertogh W, Truijen S et al. Cervical spine dysfunctions in patients with chronic subjective tinnitus. Otol Neurotol 2015; 36(4): 741-745.
  26. McKenna L, Handscomb L, Hoare DJ et al. A scientific cognitive-behavioral model of tinnitus: Novel conceptualizations of tinnitus distress. Front Neurol 2014; 6(5): 196.