Tinnitus and Cognition: Linked?

Tinnitus is conscious auditory perception without corresponding external stimuli resulting from neuronal activity along auditory pathway either in peripheral or central auditory system. The exact origin, pathophysiologic pathway and its treatment is still under exploration. The main risk factor is hearing loss, but can occur in patients with normal hearing. Auditory brainstem response test helps to objectify this subjective complaint and aid in locating its origin. P300 is late latency auditory evoked potential, objective marker of cognitive potential. The purpose of our study was to ascertain any significant difference in P300 latency and amplitude values in cases of sensorineural hearing loss with tinnitus when compared to controls (normal hearing subjects) and also to find any correlation between severity of tinnitus and cognition. This was a case control study conducted at the department of ENT at Safdarjung Hospital, New Delhi between September 2016 to March 2018. The study comprised of one hundred and six patients, out of which fifty five patients were having sensorineural hearing loss with tinnitus and fifty one patients were normal hearing subjects. General medical and audiological history and examination was done. Significant increase in P300 latency and decrease in P300 amplitude was found in sensorineural hearing loss with tinnitus cases on comparing with controls. The similar pattern of P300 values was observed on increasing severity of tinnitus and degree of hearing loss. Hence, results revealed the role of cognition and involvement of central auditory pathway in tinnitus generation.