Retrocochlear Investigation in Individuals with Tinnitus
Introduction: Tinnitus is a common symptom, occurring in approximately 15% of the general population. It causes a considerable morbidity and may interfere with sleep, concentration, emotional state, and the social life. Moreover, tinnitus can be a consequence of a compression of the cochlear nerve and the cochlear blood supply disruptions caused by the eighth cranial nerve.
Objective: The objective of this study was to investigate possible retrocochlear alterations in individuals with tinnitus.
Method: In this study, 50 patients with tinnitus were evaluated in a tertiary referral center, they underwent a pure tone audiometry and auditory brainstem response.
Results: The mean age of participants was 54 years (79 ± 10), predominantly female (68%), 52% reported unilateral tinnitus. In relation to hearing acuity, on the right ear, 76% (n = 38) had normal hearing; 16% (n = 8) mild hearing loss; 4% (n = 2) moderate; 2% (n = 1) severe; and 2% (n = 1) profound, all of them sensorineural type. On the left ear, 74% (n = 37) had normal hearing; 10% (n = 5) mild hearing loss; and 16% (n = 8) moderate, and 92.3% (n = 12) were sensorineural and 7.6% (n = 1) mixed type. The mean absolute and interpeak latencies of ABR in both ears were within normal limits. Patients who had profound hearing loss needed to be referred for imaging examination to clarify the diagnosis.
Conclusion: The majority of the individuals with tinnitus, being unilateral or bilateral, had normal hearing acuity and even with hearing loss this was characterized by cochlear type.
Keywords: Tinnitus, hearing, hearing loss, sensorineural, retrocochlear.