Tinnitus corresponds to the perception of a noise or sound in the absence of any tangible external acoustic stimulus. It is considered a symptom rather than a disease, as it always reflects an underlying cause. Today, 11.9 to 30.3% of adults worldwide suffer from tinnitus. However, only 0.5 to 3% of them feel that this condition affects their quality of life.
The prevalence of tinnitus increases in the 65-69 age group and then decreases. Numerous factors explain this prevalence, such as leisure or professional activities that expose individuals to loud noises. Tinnitus is generally associated with hearing loss, which is diagnosed in a large proportion of patients. This is most often explained by the use of ototoxic medications, certain pathologies, and infections that impair auditory function, damage the cochlea, and cause neural changes in the central auditory system. In some people, tinnitus can also be modulated or triggered by signals originating from the somatomotor, visuomotor, and somatosensory systems. In other words, the acoustic characteristics of your tinnitus (pitch and intensity) can change, at least temporarily, under the effect of external stimuli: powerful muscle contractions of the limbs, neck, or head, pressure on myofascial trigger points, electrical stimulation of the median nerve, skin stimulation of the hand, etc. Most affected people seek to understand why their tinnitus varies so much. For many patients, the perceived noise changes from one day to the next or worsens at a specific time of day. Others see symptoms appear after a nap. Still others feel fine upon waking, but hear the sound gradually become louder throughout the day. Some patients even notice an intensification of their tinnitus when they move their jaw, head, or body in a certain way. There are many explanations for these variations: increased salt intake, stress levels, pathological factors, environmental conditions, all of which are elements responsible for short-term modulation. That said, many people who experience this type of sensation have what is called somatic tinnitus. But before going into detail, let's review tinnitus in general.
Tinnitus in brief
As we have just seen, tinnitus refers to the perception of a sound or whistling in the ears. Most of the time, it results from an underlying problem: circulatory disorder, hearing loss, or ear damage. Although it sometimes degrades quality of life and seriously interferes with daily activities, it is generally not life-threatening. The most common manifestations are the perception of phantom noises in the ears, such as:
Clicking
Humming
Hissing
Rumbling
Whistling
Buzzing
These phantom noises vary in intensity, from faint to loud, and can affect one or both ears. In some cases, the sound is so loud that it prevents the person from hearing external noises or concentrating. Tinnitus can also be permanent or come and go. That said, there are two main types of tinnitus, one being significantly more common than the other:
Subjective tinnitus
This is the type of tinnitus that only the patient hears, and it is the most common. Subjective tinnitus can have very diverse origins:
Problems with the middle, inner, or outer ear
Damage to the auditory nerves
Abnormalities in the area of the brain that interprets nerve signals as sound, i.e., your auditory pathways
Objective tinnitus
This is tinnitus that a doctor can hear when examining the patient, but it is extremely rare. Objective tinnitus can be caused by:
Damage to the ossicles of the middle ear
Muscle contractions
Vascular disorders
What is somatic tinnitus?
Somatic tinnitus is a type of tinnitus in which the body's sensory system can worsen, influence, or in some way provoke the perceived noises. The term somatic comes from a Greek word meaning "of the body." Somatic signals are sensory signals generated by muscle position sensors in the tongue, arms, torso, face, head, neck, and temporomandibular joint (TMJ). The most frequent disruptive somatic signal occurs during a spasm of the sternocleidomastoid muscle. This is a large muscle located under the ear, on each side of the neck, which is involved in rotating the head. In some patients, any movement that puts tension on the neck (leaning over to look into a microscope, sleeping on an unsuitable pillow, or any such activity) causes a muscle spasm that triggers tinnitus. The spasm and the resulting tinnitus do not necessarily appear immediately: they can occur a few hours after twisting the neck. Furthermore, some patient groups manage to modulate their tinnitus through certain eye movements: this is called gaze-evoked tinnitus. TMJ dysfunction and dental problems can also cause somatic tinnitus. Among the dental problems involved, impacted wisdom teeth or dental abscesses are frequent causes. TMJ dysfunction, meanwhile, occurs when the lower jaw is no longer correctly aligned with the skull. Finally, somatic tinnitus generally affects only one ear. Several signs suggest a somatic origin:
A recurring daily rhythm
Variable localization
Neck, head, or dental problems without prior hearing loss
Variations in noise intensity
Intermittent nature
When somatic modulation of tinnitus is observed, it is generally associated with an underlying somatic disorder. If your tinnitus seems to be preceded by somatic disorders or is strictly linked to them, it likely stems from problems with the musculoskeletal system rather than your ears: this is referred to as somatic tinnitus.
The main risk factors for somatic tinnitus
In classic tinnitus, the usual risk factors are hearing disorders, male gender, and age. Patients with somatic tinnitus, however, present a different profile: they are generally younger, with a high proportion of women, and have no hearing problems. Most of the time, these patients have normal hearing. The musculoskeletal disorders most often involved in somatic tinnitus concern the cervical spine and the temporomandibular joint. And as we have seen, this type of tinnitus is modulated by pressure exerted on the head, limbs, or neck, by gaze direction, by electrical stimulation of the median nerve, and by muscle contractions. Nevertheless, the modulation of your tinnitus alone cannot serve as an indicator to establish its somatic origin. This phenomenon is indeed a fundamental characteristic of all types of tinnitus, just like whistling or buzzing. Studies show, moreover, that somatic modulation is observed in about two-thirds of people suffering from tinnitus. That said, the TMJ remains the most frequently affected area in patients with somatic tinnitus. These people influence their symptoms by pressing on the temporomandibular joint or by moving their jaw. They also have a significantly higher prevalence of craniomandibular disorders.
What is the role of the dorsal cochlear nucleus (DCN) in somatic tinnitus?
The dorsal cochlear nucleus, or DCN, is the first relay (the first synapse) through which auditory signals pass before reaching the auditory cortex to be processed. The DCN is located at the base of the brain, with the term dorsal designating the posterior part of the cochlear nucleus. It is the most essential brainstem region for transmitting auditory signals to the areas of the auditory cortex. It receives auditory signals from the cochlear hair cells, which are responsible for detecting sound, as well as signals associated with eye movements. The DCN also receives information from muscle position sensors and transmits it to other regions of the brain. Acoustic data from your ears and sensory data from muscles are thus sent simultaneously to the brain, at the brainstem level. The DCN can be damaged in multiple ways: blows to the head, acoustic trauma, teeth grinding, whiplash, muscle spasms, TMJ dysfunction, among others. Once the DCN is injured, your neural structures shift into a state of hyperactivity that creates interference between sensory signals and auditory signals. At this stage, sensory input influences auditory input and can worsen, provoke, or modulate your tinnitus. Although sound sensations seem to come from the ear, the nerve impulses do not originate in the ear, but in the DCN. Given the importance of the DCN in tinnitus, it is often said that this condition is primarily a brain phenomenon. Proof of this is that tinnitus persists even after the auditory nerve is severed, and that deaf people also suffer from it.
How does somatic tinnitus occur?
As we have already seen, somatic (or somatosensory) tinnitus is a form of subjective tinnitus caused by sensory information sent to the brain from the jaw or the cervical spine. The somatosensory system, which is part of your central nervous system, reacts to certain changes occurring in your body. This complex network of sensory neurons responds to pressure, pain, temperature, and movement. Thus, when changes such as muscle spasms appear in the temporomandibular or cervical regions, somatic tinnitus can result. It is also called cervicogenic or transmission tinnitus. The term transmission refers to the fact that it is caused by mechanisms outside the ear, while the term cervicogenic means that it originates in the cervical spine, nerves, and muscles of the neck.
What is the link between muscle spasms of the neck or jaw and whistling or buzzing in the ears?
Your body transmits sensory information to the brain via nerve fibers that pass through the trigeminal ganglion or dorsal root ganglia. As some of these fibers also project to the auditory system, these signals mislead your brain and make it believe it is hearing sounds.
The causes of somatic tinnitus
Here are some of the causes of somatic tinnitus:
Neck problems
Anything that puts your neck under tension or rotates it can cause tinnitus: leaning over to look into a microscope, adopting a poor head position in front of a computer keyboard, sleeping on a pillow that is too thick. Furthermore, contracted cervical muscles alone are enough to trigger tinnitus.
Cervical trauma
Neck injuries following a sports accident, osteoarthritis, or a car accident can lead to whistling in the ears. During such incidents, the head can be thrown violently forward and then backward, as in a car accident, which damages the nerves, ligaments, and muscles of the neck. Athletes playing sports like American football can also suffer this type of injury on the field. Poor work posture or poor sleeping position can cause a pinched nerve and osteoarthritis, and damage the disc located between your cervical vertebrae. All these factors can lead to somatic tinnitus.
Dental problems
Dental problems such as an impacted wisdom tooth or an abscess that causes inflammation of the jaw joint can lead to tinnitus. Anyone who has suffered from TMJ dysfunction knows where the temporomandibular joint is located and how intense the pain can be. TMJ dysfunction can cause spasms or tension in the ligaments and muscles of the face. To treat TMJ, the patient must either wear a custom-made splint at night, take anti-inflammatories, or have massage therapy.
The diagnosis of somatic tinnitus
The diagnosis of somatic tinnitus is made by a healthcare professional when the buzzing or whistling in the ear coincides with jaw or neck pain. A physical therapist or physician can make this diagnosis after having the patient fill out the Bournemouth Cervical Questionnaire, which explores the patient's symptoms, and after performing various tests on the cervical spine. Here is a detailed list of criteria for identifying somatic tinnitus. If present, they strongly indicate that your tinnitus is somatic, or at least that its cause originates from the somatosensory system.
First criterion: tinnitus modulation
If you can modulate your tinnitus by voluntary movement of the eyes, neck, jaw, or head, it likely originates from the somatosensory system
If you manage to modulate your tinnitus through somatic maneuvers such as jaw clenching
If your tinnitus is modulated by pressure exerted on a myofascial trigger point
All these modulation capabilities strongly indicate that your tinnitus is subject to somatosensory influence
Characteristics of somatic tinnitus:
Jaw or neck pain that appears at the same time as your tinnitus
Jaw and neck pain that worsens at the same time as the tinnitus.
Tinnitus preceded by neck or head trauma
Tinnitus that increases when you adopt poor posture
Varying tinnitus intensity, pitch, and localization
In the case of unilateral tinnitus, an audiogram that does not explain this lateralization
Associated symptoms that suggest somatic tinnitus:
Somatic tinnitus is accompanied by persistent pain in the cervical spine, shoulder girdle, or head
Somatic tinnitus can be identified by the presence of myofascial trigger points, most often painful to palpation.
An increase in muscle tension generally accompanies somatic tinnitus
Temporomandibular disorders can help identify somatic tinnitus
Somatic tinnitus is associated with bruxism or teeth clenching
Somatic tinnitus is accompanied by dental problems or pathologies
The best therapies for somatic tinnitus
Many therapies have proven effective in relieving somatosensory tinnitus of cervical origin. Although there is no definitive cure, managing the cause of the problem allows you to control your symptoms. Somatic tinnitus can even disappear in people who undergo physical therapy or chiropractic treatment. Here are some of these therapies:
Therapeutic massage
A massage can relieve you of your tinnitus by correcting posture problems, relaxing contracted muscles, and reducing stress. Two main areas, around the neck and the ear, can be massaged to alleviate symptoms:
The masseter muscle
This is the muscle that connects your jaw to your skull. It is located at the jaw, near the earlobe, and it is the most powerful muscle in the body relative to its size. When contracted, it causes a structural misalignment that leads to whistling in the ear. A massage aimed at releasing tension and realigning bony structures can relieve you of your tinnitus.
The mastoid process
This is the area of the skull behind the ear, connected to the muscles surrounding the neck and ear. By massaging the mastoid process with a Swedish massage, you release tension in the ear and neck muscles, which helps to correct cervical alignment.
Cervical exercises
Certain exercises are recommended to alleviate tinnitus. Stretching and a postural rehabilitation program are also beneficial. Postural work strengthens the neck muscles and relieves pain and problems related to cervical discs. Anything that stretches contracted muscles in the neck and shoulders can prevent nerve signals from generating tinnitus noise. Here is a simple exercise to perform while sitting upright on a chair. Raise your right hand, place it on the left side of the top of your head, and gently pull your head toward your right shoulder. Go until you feel a light stretch in the neck muscles on the left side. Then repeat the same movement with the left hand and on the right side.
Transcutaneous electrical nerve stimulation (TENS)
This device uses an electric current to stimulate your nerves, generally for therapeutic purposes. The TENS device can be applied near the upper cervical nerve or near the ear to relax the muscles.
Lidocaine and corticosteroid injections
A doctor may prescribe these injections to stop the inflammation and pain that could be the cause of your somatic tinnitus.
Mechanical manipulations
A chiropractor or physical therapist can manipulate your somatic structures to normalize the jaw or cervical spine. Indeed, when structural deviations cause muscle spasms or tension, correcting them can relieve your tinnitus.
Acupressure and acupuncture
Acupuncture has demonstrated its effectiveness in the treatment of many types of tinnitus. The same is true for acupressure, which can provide relief through the massage of the correct pressure points.
TMJ and somatic tinnitus
As we have seen in this article, somatic tinnitus can sometimes signal a temporomandibular joint disorder. You should therefore inform your doctor of all the symptoms you are experiencing so that the TMJ can be properly managed. But how do you know if your tinnitus is linked to TMJ? Here are the signs to look out for:
Cracking or clicking sounds when you open and close your mouth
Past jaw trauma
Difficulty opening your mouth or chewing.
Osteoarthritis
Limited range of motion when opening or closing your mouth
Face or jaw pain
If you have any of these symptoms, your tinnitus is very likely rooted in a temporomandibular joint disorder. You simply need to consult a dental surgeon, who will direct you to the appropriate treatment.
How to reduce the effects of TMJ-associated tinnitus with an occlusal splint
By taking steps to treat your TMJ, you help relieve the aural symptoms you are experiencing, such as somatic tinnitus or hearing loss. When you make an appointment with your dentist to discuss your TMJ, describe all the symptoms you are feeling so they can choose the method best suited to your situation. TMJ can be treated in many ways, from relaxation techniques and exercises to surgery. Your dentist may even combine several approaches. One of the most effective and common solutions for relieving TMJ is the occlusal splint. It will be recommended if your TMJ is due to bruxism. That said, if a splint is prescribed, here are a few things to consider before using it:
Is it easy to maintain: does it need to be soaked to clean it, or can I simply put it in the dishwasher?
Is it comfortable: can I drink, eat, and talk with the splint in place?
Is it simple to use: can I mold it easily?
Conclusion
As we have seen in this article, somatic tinnitus is caused by problems in the somatosensory system, resulting in whistling, buzzing, or humming sounds with no external source. It is therefore important to consult a doctor to correctly identify the cause of your somatic tinnitus and implement the appropriate treatment. Remember that tinnitus is not the problem in itself: it is a symptom of an underlying issue. Treating the cause of your tinnitus will therefore help it disappear. If you have any comments or questions, please leave them below.
