Bilateral inferior colliculus infarction after embolization of a cerebellar arteriovenous malformation: illustrative case.

Background: Bilateral inferior colliculus (IC) infarction is a rare condition that can lead to severe auditory deficits. Cerebellar arteriovenous malformations (AVMs) treated with endovascular embolization pose a risk for ischemic complications affecting the brainstem.

Observations: A 54-year-old male presented with intermittent headaches and imbalance, and, following a fall, a subarachnoid hemorrhage and cerebellar AVM were identified. After endovascular embolization, the patient developed bilateral moderate hearing loss, and MRI revealed acute ischemia in both ICs. Despite treatment with intravenous hydration and prednisolone, the patient's hearing loss progressed to total sensorineural hearing loss. Audiometry and auditory brainstem response testing showed reduced amplitudes, although some responses were still present. At 4 months, further amplitude reduction occurred, but the patient began using written communication and lipreading.

Lessons: Bilateral IC infarction is an uncommon but significant complication following cerebellar AVM embolization. Early recognition and supportive care, including rehabilitation, are essential for patient adaptation. To minimize the risk of brainstem infarction, embolization should be performed as close to the AVM nidus as possible, avoiding unnecessary involvement of brainstem feeders. https://thejns.org/doi/10.3171/CASE24712.