Tinnitus : new insights into pathophysiology, diagnosis and treatment

The word `tinnitus' originates from the Latin word `tinnire', which means 'jingling' (1). The perception of tinnitus is experienced by many people over the world, although it is more common in Caucasian populations than in African-American populations (2;3). Men are described to experience this sensation more often than women, possibly related to the more impaired hearing thresholds in the male population (2;3). The prevalence of tinnitus increases with advancing age (3), related to the severity of hearing loss accompanying aging (2). Prevalence percentages varying from 10% to 30% (2;4) of the adult population, have been described. Tinnitus can be perceived as an intermittent or a continuous sound (1), which can be constant or fluctuating in intensity and pitch throughout the day (5).The tinnitus perception frequently does not resemble a normal sound, so patients are not always able to describe the sound they hear or select a sound which is similar to their tinnitus. Matching the tinnitus to sounds showed levels of loudness just 10 dB to 30 dB above hearing thresholds (1;6). Therefore, tinnitus is frequently much weaker than the patients' perception of their tinnitus. A wide variation exists between the influence tinnitus has on every day activities. It seems to slightly bother some patients, but has much impact on quality of life in others. Severe tinnitus is frequently associated with a variety of audiological symptoms (e.g. hearing loss, hyperacusis and a distorted perception of sounds ), affective disorders (e.g. depression and anxiety), as well as symptoms affecting everyday mental and physical functioning (e.g. insomnia, concentration problems, loss of silence, irritability). Therefore, tinnitus can be defined as a chronic stressor for some people (7). 'Clinical significant tinnitus' is defined as 'tinnitus that reached the level of severity for a patient to seek some type of professional help' (8).