• Spontaneous neural activity
• hyperexcitability
• hearing
• neurootology
• neuroophthalmology
• tremor
• dystonia

Tinnitus is one of the most common neurological symptoms. Approximately, one-third adults experience it once in their life time, 10% of them experience prolonged tinnitus and 5% suffer from severely disturbing tinnitus.1 The term ‘tinnitus’ is derived from the Latin word ‘tinnire’, which means ‘ringing’. Tinnitus is defined as perception of sound in the absence of corresponding external auditory stimuli.

Tinnitus is not a ‘modern’ condition. The famous composer Ludwig van Beethoven (1770–1827) suffered from tinnitus and Charles Darwin (1809–1882) kept daily records of his tinnitus. The description of tinnitus in the ancient literature was remarkably influenced by the cultural factors. The ancient Egyptians believed that tinnitus occurred from a ‘bewitched’ ear and the ancient Asian mysticism considered tinnitus as ‘sensitivity to the divine’.2 The Romans presumed that tinnitus had common pathophysiology as seizures.2

Clinical observations and psychoacoustic studies drove tinnitus research for several decades in the 20th century, but without definite answers for its pathophysiology. Studies in the late 1970s and early 1980s suggested the role of increased activity in the auditory nerve as a cause of tinnitus.3 ,4 However, the peripheral theory for tinnitus had significant caveats. Eighth nerve transaction did not resolve tinnitus in human subjects, but it rather remained unchanged or even got worse.5 Development of animal models of tinnitus was a breakthrough …