The Evaluation of the Cochlear Aqueduct and Internal Acoustic Canal in Patients with Unilateral Subjective Tinnitus and Normal Hearing

Objective: We investigated the relationship between idiopathic subjective tinnitus and internal acoustic canal, cochlear aqueduct, vestibule, and lateral semicircular canal measurements by temporal magnetic resonance imaging.

Methods: In this retrospective study, temporal magnetic resonance imaging sections of 25 patients (8 males and 17 females) with unilateral tinnitus and normal hearing were included. The internal acoustic canal, cochlear aqueduct, vestibule, and lateral semicircular canal measurements and internal acoustic canal and cochlear aqueduct shape classification were determined in the ipsilateral tinnitus side and contralateral non-tinnitus side.

Results: The cochlear aqueduct length and width and internal acoustic canal opening width, length, width, and area of the ipsilateral tinnitus side were not different from the contralateral side. Similarly, the vestibule area and lateral semicircular canal height and width values were not different between the ipsilateral tinnitus side and the contralateral side. The main cochlear aqueduct type was type 2 in both ipsilateral and contralateral sides. For the internal acoustic canal types, cylindrical and funnel shapes were the most common types for the ipsilateral tinnitus side and contralateral side. There were positive correlations between the internal acoustic canal and vestibule areas; cochlear aqueduct length and internal acoustic canal areas; cochlear aqueduct width and width of the lateral semicircular canal; internal acoustic canal area and length and cochlear aqueduct length; internal acoustic canal opening width and height of the lateral semicircular canal; and width of the lateral semicircular canal dimensions. In older patients, the ipsilateral internal acoustic canal area was found to be smaller.

Conclusions: In idiopathic subjective tinnitus, there were no important pathologies detected in the internal acoustic canal, cochlear aqueduct, vestibule area, and lateral semicircular canal. We concluded that there are no statistically significant morphometric differences compared to the healthy side in the internal acoustic canal, cochlear aqueduct, vestibule, and lateral semicircular canal areas detected by temporal magnetic resonance imaging in patients with unilateral subjective tinnitus and normal hearing.

Cite this article as: Yılmazsoy Y, Bayar Muluk N, Özdemir A, Şencan Z. The evaluation of the cochlear aqueduct and internal acoustic canal in patients with unilateral subjective tinnitus and normal hearing. B-ENT. 2023;19(2):94-102.