Can Anatomical Variations of AICA Loop be a Cause of Hearing Loss which can Affect the Laterality of Tinnitus Also?

Objective: We aimed to reveal whether the vascular loop variations created by the antero-inferior cerebellar artery (AICA) in the cerebellopontine angle (CPA) and the internal acoustic canal (IAC) can be a cause, that can affect laterality of tinnitus and cause hearing loss. Methods: The data and the magnetic resonance imaging scans were collected retrospectively and 109 patients with tinnitus were included in the study. Data were recorded according to the patients’ duration and laterality of tinnitus, laterality, type and frequency of hearing loss ,contact type and extension of AICA with remarking the side of the vascular loop. Results: A statistically significant difference was found in between the left ear high frequency (HF) hearing loss (p=0.042) and extension type of the AICA. Also showed statistically significant results in between left sided tinnitus (p=0.030) and the Chavda classification. Besides the patients who had right sided tinnitus, was found to be in relation with the right sided contact type as the p value was 0.023. Conclusion: Our results suggest that AICA variations in CPA and IAC can cause HF hearing loss as well as particularly affect the side of tinnitus. Nevertheless, this relationship must be confirmed by more advanced audiological and imaging techniques.