There is a growing body of evidence suggesting that some tinnitus is a consequence of neuroplastic alterations in the central auditory pathway. These alterations are assumed to result from a disturbed sensory input, caused by hearing loss. Hearing loss could indeed cause a homeostatic response of neurons in the central auditory system, and therefore cause tinnitus.
Supporting the idea that central reorganization is overestimated as "the" cause of tinnitus, a recent study by Wineland et al showed no changes in central connectivity of auditory cortex or other key cortical regions (Wineland et al, 2012). Considering other parts of the brain, Ueyama et al (2013) reported that there was increased fMRI activity in the bilateral rectus gyri, as well as cingulate gyri correlating with distress. Loudness was correlated with values in the thalamus, bilateral hippocampus and left caudate. In other words, the changes in the brain associated with tinnitus seem to be associated with emotional reaction (e.g. cingulate), and input systems (e.g. thalamus). There are a few areas whose role is not so obvious (e.g. caudate). This makes a more sense than the Wineland result, but of course, they were measuring different things. MRI studies related to audition or dizziness must be interpreted with great caution as the magnetic field of the MRI stimulates the inner ear, and because MRI scanners are noisy.
Health care professionals who incline to offer patients an option or strategy to deal with tinnitus are confronted with the variability inherent to this disorder.5 The cause of tinnitus can vary, although people who experience tinnitus have usually first developed hearing loss due to ageing or from exposure to loud noise that caused peripheral auditory damage. In fact, the number of tinnitus sufferers that develop the constant ringing due to hearing loss may be even higher than thought, as some tinnitus sufferers only appear to have normal hearing when thresholds at frequencies below 8 kHz are measured. Less frequently, tinnitus may also occur after a head or neck injury, or due to the presence of an acoustic neuroma. Certain medications may also contribute to the development of tinnitus through effects on hair cells in the inner ear or via mechanisms that are not yet well understood.6 This variety in cause has been the first part of the challenge in developing a “cure” or effective treatment for tinnitus. However, even for the largest group of tinnitus sufferers (those who may develop tinnitus due to hearing damage), effective treatments have been hard to come by.
This well-designed study found that using CBT alongside elements of standard therapy can help patients with tinnitus of varying severity. However, the differences in outcomes between the two groups were quite small, and this technique can only help manage tinnitus rather than curing it, as some papers implied. Also, the patients in the study were followed for only 12 months, so it is unclear whether this approach can help in the longer term.
Patients with head or neck injury may have particularly loud and disturbing tinnitus (Folmer and Griest, 2003). Tinnitus due to neck injury is the most common type of "somatic tinnitus". Somatic tinnitus means that the tinnitus is coming from something other than the inner ear. Tinnitus from a clear cut inner ear disorder frequently changes loudness or pitch when one simply touches the area around the ear. This is thought to be due to somatic modulation of tinnitus. We have encountered patients who have excellent responses to cervical epidural steroids, and in persons who have both severe tinnitus and significant cervical nerve root compression, we think this is worth trying as treatment.
Tinnitus retraining therapy is a form of treatment that tries to retrain the nerve pathways associated with hearing that may allow the brain to get used to the abnormal sounds. Habituation allows the brain to ignore the tinnitus noise signal, and it allows the person to become unaware that it is present unless they specifically concentrate on the noise. This treatment involves counseling and wearing a sound generator. Audiologists and otolaryngologists often work together in offering this treatment.
When tinnitus is unexpected and unwelcomed, it can lead to a negative reaction to the tinnitus. This can create a vicious cycle. When tinnitus is perceived, it can prompt emotions, including frustration, fear, unhappiness, etc. These can, in turn, cause physical reactions such as anxiety and stress. This reinforces the tinnitus and perpetuates the cycle.
Atherosclerosis. With age and buildup of cholesterol and other deposits, major blood vessels close to your middle and inner ear lose some of their elasticity — the ability to flex or expand slightly with each heartbeat. That causes blood flow to become more forceful, making it easier for your ear to detect the beats. You can generally hear this type of tinnitus in both ears.