Learning objectives
To evaluate radiological characteristics of the anterior inferior cerebellar artery [AICA] within the cerebellopontine angle [CPA] and the internal auditory canal [IAC].
To investigate the course of AICA as well as the relationship between AICA and surrounding structures [VII & VIII cranial nerves].
To correlate these characteristics with ipsilateral auditory symptoms.
Background
The CPA is a triangular shaped space filled with cerebrospinal fluid that lies anterolaterally to the junction of the pons and cerebellum. It contains cranial nerves [facial nerve VII and vestibulocochlear nerve VIII] and the AICA. [Fig 1][Fig 2] The IAC, which is a nerve canal surrounded by bone, rises anterolaterally from the CPA to reach the peripheral cochleovestibular organs. The IAC contains cranial nerves VII and VIII, which are responsible for facial muscle movement, hearing and balance.
The AICA usually arises from the basilar...
Findings and procedure details
Magnetic resonance imaging [MRI] is widely used to visualize this anatomical region. Thin slice T2-weighted MRI images employing 3-dimensional transformation [3D T2 DRIVE images]were evaluated in the axial plane.
The AICA follows a highly variable course and vascular loops can be identified in many asymptomatic individuals.
The correlation of anterior inferior cerebellar artery [AICA] vascular loop around cerebellopontine angle [CPA] and otologic symptoms remains controversial. Vascular compression of the seventh and eighth cranial nerves in the CPA may lead to hearing loss, tinnitus, vertigo, dizziness,...
Conclusion
Identifying the prevalence of the vascular loops of the AICA primarily depends on diagnostic technique.
AICA loop anatomical variances in the CPA-IAC is based on multiple radiological grading systems.
The relationship between the AICA loop in the CPA-IAC region and otological symptoms in patients still remains controversial.
Personal information and conflict of interest
L. A. Abd El-Gawad:
Nothing to disclose
References
[1] Leng Y, Lei P, Liu Y, et al. [2022] Vascular loops in cerebellopontine angle in patients with unilateral idiopathic sudden sensorineural hearing loss: Evaluations by three radiological grading systems. Laryngoscope Investigative Otolaryngology; 7:1532-40.
[2] Tuna Yalçınozan E, Küçükçiloğlu Y. [2022] Can Anatomical Variations of AICA Loop be a Cause of Hearing Loss which can Affect the Laterality of Tinnitus Also? Bezmialem Science; 10[5]:596-601.
[3] Bhatia A, Phukan B, Sharma B, et al. [2021] Is There an Association between the Anteroinferior Cerebellar Artery Vascular Loop...