- Published on 18 June 2015
Frequently related to pain and myofascial trigger points, somatosensory tinnitus is a very common type of tinnitus that requires specific assessment and treatment protocols. Medical history should investigate pain in the head, face, ervical spine, and shoulder girdle regions, while physical examination should assess the patient's posture, the presence of myofascial trigger points, and tinnitus modulation. Physical therapy should be customized according the patient's history and physical examination.
There are essentially two types of tinnitus where physical therapy is recommended: somatosensory tinnitus and tinnitus related to emotional factors. Somatosensory tinnitus is caused by musculoskeletal disorders, of which myofascial pain syndrome is one of the most common. This syndrome is characterized by regional pain and myofascial trigger points (TPs), which are hypersensitive nodes in a palpable and tense muscle band that produce both local and referred pain (Travell and Simons, 1998).
In recent studies a strong relationship has been observed between tinnitus and TPs (Rocha and Sanchez, 2007, 2008, 2012). A person with tinnitus is nearly five times more likely to present TPs, which often produce a modulation in the intensity or type of tinnitus when palpated. Interestingly, muscles located near the head are the most likely to produce such modulation.
The association between tinnitus and pain, regardless of the presence of TPs, has been demonstrated by similarities in their pathophysiology, qualitative features, and treatment approaches. Patients with tinnitus are almost three times more likely to experience pain, and the improvement of tinnitus is directly related to the improvement of pain (Rocha e Sanchez, 2012). A similar direct relationship is found in bruxism, where patients with orofacial pain are more likely to have tinnitus (Camparis et al., 2005).
AUDITORY AND SOMATOSENSORY PATHWAYS
The association between the auditory and somatosensory pathways occurs due to subcortical connections in the dorsal cochlear nucleus. This key point contains multitasking neurons that receive signals from both the auditory and the somatosensory pathways, many of them from the trigeminal ganglion. This would be the reason why bruxism can cause or modulate tinnitus. The shorter the interval between the stimulus of one pathway relative to the other, the greater the interaction between them (Koehler et al., 2013).
HISTORY AND PHYSICAL EXAMINATION
History and physical examination are the basis for investigating somatosensory tinnitus. Medical history should determine if the patient has pain and if it is located in the head, face, neck, or shoulder girdle. The patient should also be asked whether the tinnitus started before, after, or simultaneously to the pain. This can help determine whether a muscle disorder is causing the tinnitus. It is interesting to investigate whether the tinnitus is on the same side as the muscle tension or pain, which is often the case in somatosensory tinnitus.
The patient’s history may show that the tinnitus started after a head or neck trauma, a dental procedure, cervical manipulation, or periods of intense bruxism. The patient may also report a modulation of tinnitus during or after using a computer (poor posture), using a different pillow, or in periods of more intense pain.
Physical examination should start with an assessment of head and upper limb posture. Head lateralization or protrusion and shoulder elevation or protrusion should be investigated. Physical examination also includes modulation tests performed in a silent room where the patient can clearly perceive the tinnitus. Grades from 0 to 10 in the visual analogue scale (VAS), assessed before and during the test, help determine whether the intensity of tinnitus increases or decreases. Decreasing the intensity of tinnitus during testing seems to be an important condition for achieving significant therapeutic results.
TPs are investigated in the splenius, sternocleidomastoid, trapezius, infraspinatus, masseter, and temporal muscles of the head and neck. During palpation the patient should be asked whether the tinnitus modulates or not. The professional should receive specific training to perform this type of evaluation. Modulation of tinnitus can also be investigated through active mandibular (opening, closing, protrusion and lateralization) and cervical (flexion, extension, rotation and lateralization) movements held for a period of up to 5 seconds. Isometric contraction of the head and jaw area, eye movements (gazeevoked tinnitus) and facial movements can also be performed to investigate modulation. A test should be made with stretching exercises held for 30 seconds to assess changes in the intensity of tinnitus. The exercises should focus primarily on the neck and shoulder area.
Bruxism and other temporomandibular disorders should be assessed by an otolaryngologist so that, if necessary, the patient can be referred to a dentist and/or physical therapist. Signs like a jagged tongue, dental attrition, and a linea alba in the jugal mucosa; limited, deviated, or painful jaw opening; muscle pain, either spontaneous or on palpation; and joint crepitation should be investigated. Finally, a normal audiometry in the presence of tinnitus and pain leads to a diagnosis of somatosensory tinnitus, a condition that can be effectively treated with physical therapy.
An evidence-based treatment called myofascial therapy is now available to release TPs related to tinnitus (Rocha and Sanchez, 2012). This is a manual therapy based on applying digital pressure to TPs, followed by myofascial manoeuvres similar to stretching exercises. Dry needling has also been widely used in clinical practice to treat tinnitus due to TPs, but scientific evidence of its effectiveness is still lacking. Other approaches with demonstrated effectiveness against somatosensory tinnitus (regardless of the presence of TPs) include atlas therapy (Kaute, 1998), TENS (transcutaneous electrical stimulation) near the ear region (Herraiz et al., 2007), osteopathy/chiropractic, massage (Kessinger and Boneva, 2000), and auriculotherapy (Okada et al., 2006). Specific techniques for the temporomandibular region have also been reported in several published papers. In the case of tinnitus related to emotional factors, physical therapy can help improve anxiety and depression by teaching patients deep diaphragmatic breathing techniques, the countdown technique (counting from 60 to 0), meditation (using images and words), Jacobson’s progressive relaxation, and mindfulness.
“Hypermodulating” patients, i.e. those that present modulation in all tests on physical examination, require a different approach. These patients should first receive medication before being referred to physical therapy. Physical therapy should be customized according to the findings on clinical examination, and the physiotherapist needs to gain experience on the subject. Treating patients with somatosensory tinnitus is not limited to reducing pain or muscle tension. These are individuals who experience a lot of anxiety and doubts over their symptoms, and the physical therapist should be prepared to assist them.
In conclusion, it is important to note that somatosensory tinnitus should be addressed by a multidisciplinary team, and its improvement is closely related to the duration of symptoms. Therefore, it is essential that otolaryngologists be prepared to assess this type of tinnitus, referring the patient to a physical therapist as soon as possible. Furthermore, it should be remembered that medication alone in cases of somatosensory tinnitus does not treat causes such as postural, vertebral or articular disorders.
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