Vascular Loops of AICA Causing Neuro-Otologic Symptoms: Fact or Fiction??

The aim of this study is to identify, localize, and document the relationship between the AICA loop (Anterior Inferior Cerebellar Artery loop) and VII and VIII nerve complexes, and its symptomatic correlation. 50 patients with MRI Brain with 3D T2 Drive were studied from Sep 2018 to Dec 2018. Symptomatic correlation of 100 sides of the AICA loop over the VII-VIII nerve complex was analyzed prospectively. The presence of a vascular loop on MRI was correlated with the presence of neuro-otological symptoms such as sensorineural hearing loss, tinnitus, facial palsy, and vertigo. Vascular loops were present in 25 of the 100 sides, of which 24% were associated with neuro-otological symptoms whereas 76% sides were not associated with any symptoms. The 24% sides with symptoms were further investigated and were then proven to be not because of the presence of vascular loops. The presence of vascular loops in the internal auditory canal may be an incidental finding in MRIs and may not always be a causative factor for any unexplained neuro-otologic symptoms. Specific investigations are mandatory to avoid any unnecessary surgical intervention. Further studies involving a larger number of patients are required to accurately evaluate the association between these symptoms and vascular loop.