Tinnitus is in all-too-common symptom following traumatic brain injury, particularly concussion as well as cervical whiplash injury. It is characterized by the perception of sounds which can be highly variable including ringing, hissing or buzzing that did not correspond with an external sound stimulus. There are many different causes of tinnitus, some of which are reversible or at least able to be improved with proper identification of the symptom generator. All too often clinicians tell patients to just wait and see if it gets better or when more chronic that they just must live with it but these are both inappropriate things for physicians/clinicians to be telling patients suffering from this symptom which can be quite debilitating.
Tinnitus is a pervasive public health issue that affects approximately 15% of the United States population and of that percent 10 to 20% experience symptoms that severely reduced their quality of life. Individuals with tinnitus are commonly not referred for specialty evaluation and there is often inadequate attention paid to not on otologic (the ear) tinnitus generators due to a lack of understanding among healthcare practitioners regarding the myriad causes of tinnitus as well as current treatment guidelines for same.
Tinnitus can occur after trauma to the head, cranial structures, neck and brain. Posttraumatic tinnitus can be a complex condition given the potential for multifactorial causes, the challenges of assessment and the treatment controversies. Some of the risk factors for tinnitus include history of loud noise exposure including last noise versus chronic loud noise exposure, hypertension, migraine, cardiovascular disease, tobacco use, older age, and traumatic brain injury.
Primary tinnitus is of unknown cause and may not be associated with sensorineural hearing loss were secondary tinnitus is associated with a specific underlying condition which may be related to ear pathology but can be related to urological issues, physical issues, toxic issues or vascular conditions.
Tinnitus can have many potential functional impacts including increasing stress, perpetuating and/or causing fear, irritability, depression and anxiety, impeding cognition, disrupting sleep and interfering with hearing. Treatment should focus on prioritizing how tinnitus may be negatively impacting patient’s quality of life which may differ dramatically across patient’s. The goal should be to educate regarding the condition, modulate symptoms and avoid handicap the latter relating to both emotional and physiological stressors while maintaining his normal life activities as possible.
There are different types of tinnitus that should be understood by both patients and clinicians who evaluate this condition. Specifically, tinnitus is classically divided into subjective as well as objective tinnitus with the former being heard in the head and specifically in the ear/ears whereas object of tinnitus which is rare can be heard/perceived by other people as well as the affected individuals with sounds usually produced by internal physiologic processes such as blood flow or abnormal muscle movements.
Following trauma there are many different potential etiologies of tinnitus including but not limited to the TBI itself, cervical whiplash injury, sensorineural hearing loss, conductive hearing loss, barotrauma, TMJ dysfunction, endolymphatic hydrops, perilymphatic fistula, vascular posttraumatic changes, myofascial trigger points (particularly in the sternocleidomastoid), trauma triggered migraine, among other causes.
When the clinician evaluates the patient with tinnitus following trauma an adequate history must be taken which should include the functional impact of the condition, its severity, location and duration. The character should also be assessed in terms of describing the subjective perception of the sound as this can give a clue to the nature of the tinnitus generator for example primary tinnitus tends to be ringing, buzzing or hissing whereas conditions like endolymphatic hydrops tend to present with a roaring type tinnitus and muscular abnormality such as myoclonus with a rhythmic clicking type tinnitus. When the tinnitus is heard as pulsatile then a vascular or blood vessel cause should be considered. Associated findings and aggravating factors should also be discussed. Questionnaires may be helpful in terms of further delineating the nature of the tinnitus and its functional consequences.
There are several international tinnitus guidelines that have been published. Unfortunately, the American guidelines published through the American Academy of otolaryngology-head and neck surgery are outdated and were published way back in 2014. Probably the most recent set of guidelines that are broader in terms of their scope would be out of the United Kingdom specifically the National Institute for health and care excellence (NICE) published in 2020.
For patients with acute onset tinnitus audiological referral was recommended when assessment reveals no obvious nonotological cause and/or when there is sudden onset of sensorineural hearing loss with associated tinnitus which is an indication for urgent audiometric testing due to potential need for intratympanic steroids. For chronic tinnitus (lasting greater than 6 months since onset) or patients with unilateral tinnitus or any reported hearing changes referral for comprehensive audiologic examination should occur within 4 weeks.
The tinnitus physical exam should include not only ear examination but as relevant appropriate assessment of the eye via funduscopic examination and visual field assessment at a minimum, craniocervical musculoskeletal examination, neurological assessment and as relevant vascular exam specifically relating to assessment for bruits around the ear, orbits, mastoids, as well as temporal and carotid arteries.
The audiological exam of the patient with tinnitus should be multidimensional and should include at a minimum pure-tone audiogram assessment, speech recognition testing, tympanograms, acoustic reflex testing and otoacoustic emission testing. Supplemental tinnitus testing can be helpful in further defining tinnitus characteristics as well as confirming the validity of the subjective complaint of tinnitus. These tests may include tonometer, tinnitus threshold testing, tinnitus sound matching, minimum masking level using hearing aids or maskers, loudness discomfort level and auditory brainstem evoked responses.
Radiological assessment of the head and neck is only indicated if tinnitus is localized to 1 year, is pulsatile, is associated with focal neurologic abnormalities or accompanied by asymmetric hearing loss.
It is important to acknowledge that tinnitus may also be related to/caused by medications that are prescribed to patient’s following injury and this should always be in the differential diagnosis for any patient presenting with new onset tinnitus complaints following trauma. Anti-inflammatory agents, antiseizure medications, certain antidepressants such as bupropion, dopamine agonists, proton pump inhibitors and certain hormonal agents have all been associated with new onset tinnitus.
Tinnitus treatment approach should prioritize treatment of more bothersome as opposed to non-bothersome tinnitus as well as prioritize recent onset tinnitus relative to more persistent tinnitus. There are now multiple tinnitus treatments that have been endorsed and utilized in clinical practice but the literature base for most of them is sorely lacking. A variety of sound therapies have been advocated. These products can be divided into reaction versus perception. These devices may offer some patient some degree of control over there is subjective perception of tinnitus. Those devices the fall under reaction are made to reduce the reaction to tinnitus and are either stand-alone or applications that can be downloaded to a mobile device the latter which tends to be more flexible to. Devices that reduce the perception of tinnitus are generally based upon the concept of altering neuroplasticity but require more intensive usage and tend to be more expensive. Cochlear implants have also been used for tinnitus when there is profound sensorineural hearing loss in association with tinnitus. Hearing aids are recommended when there is an indication due to comorbid hearing loss of less significant nature than those that justify cochlear implantation. Tinnitus retraining therapy has been used but efficacy is limited based on most recent studies assessing its efficacy. Cognitive behavioral therapy as a treatment approach that incorporates cognitive, behavioral and or combination of these components in a structured, time-limited fashion it is the best investigated intervention for tinnitus yet availability is limited and little data is available on long-term benefit. Neuromodulation techniques are also emerging as potential treatment strategies for tinnitus but are not currently recommended in any recent guideline. Probably the treatment of most interest based on very recent literature is in a technique called “bimodal stimulation” which she utilizes auditory stimuli combined with various forms of neurostimulation. Pilot studies have shown substantial benefits of auditory stimulation when used with concurrent electrical stimulation of the face, tongue, neck and/or vagus nerve. Other techniques that have been used include neuro biofeedback, complementary and alternative therapies, physiotherapy including manual therapy, self-help interventions, tinnitus counseling and microvascular decompression. Regarding the latter intervention, there are no recent systematic reviews to provide current recommendations for the surgical technique which involves microsurgical decompression of the 8th cranial nerve for treatment of tinnitus. Further research is clearly needed and terms of these other treatment modalities. There is no current drug therapy for tinnitus and current guidelines only recommend drug treatment for comorbid conditions such as insomnia, depression or anxiety.
If you suffer from tinnitus, please make sure to consult with appropriate resources including specialists familiar with post-traumatic tinnitus and the resources for same. You may need to consult with an audiologist, ENT, TMJD specialist (oromaxillofacial surgeon or physical therapist, or brain injury medicine subspecialist. A great source of information on tinnitus in general is the American Tinnitus Association (ATA). Their website is https://www.ata.org/.
ABOUT THE AUTHOR
NATHAN D. ZASLER, MD, DAAPM&R, FAAPM&R, FACRM, BIM, CBIST is Founder, CEO & Medical Director of Concussion Care Centre of Virginia, Ltd., as well as Tree of Life Services, Inc. Dr. Zasler is board certified in PM&R, fellowship trained in brain injury and subspecialty certified in Brain Injury Medicine. You can read more about Dr. Zasler HERE.
