To acknowledge the importance of exploring unusual locations of vestibulocochlear nerve compression resulting in chronic peripheral vestibular syndrome, such as AICA vascular loop in the internal acoustic meatus (common location is Cerebellopontine angle).

Compression of the vestibulocochlear nerve is usually located at the cerebellopontine angle and can cause disabling vestibular symptoms such as tinnitus, vertigo and hearing impairment, however a neurovascular intrameatal compression, though rare/under-recognized due to low index of suspicion or imaging techniques used, may also be associated with these symptoms.

We present a case of 78-year-old right handed man with history of hypertension, 3 years of persistent vertigo, tinnitus, decreased hearing, refractory to vestibular sedatives and head positioning maneuvers. His symptoms consequently had a negative impact on his activities of daily living.

 Initial work up including vestibulonystagmogram indicated peripheral vestibular nerve involvement.  MRI brain and C spine showed small vessel disease and mild cervical spine narrowing respectively, which did not adequately explain the patient’s symptoms.  Vitamin B12 deficiency (186pg/ml) was treated: repeat level 843 pg/ml.  TSH, A1c, autoimmune panel, vitamin E, Zinc and copper levels were normal.

 Based on persistent symptoms and suspected vestibulocochlear nerve compression etiology, a repeat brain MRI with Fast Imaging employing steady-state acquisition (FIESTA) protocol was done which demonstrated a tortuous left anterior inferior cerebellar artery extending 6mm into the internal acoustic meatus, thus offering the likely etiology of his symptoms with a consequent surgical evaluation.  Dedicated CT Angiography of head is pending at this point, and patient is being planned for endovascular treatment.

Vascular loops of the AICA may be associated with neuro-otological features. Though uncommon, an intrameatal vascular compression of the vestibulocochlear nerve should be a considered etiology in evaluation of  patients with chronic vestibular features refractory to medical therapy and apparently normal brain MRI.