From Sound to Silence: Cerebellar Abscesses and Herniation Due to Cochlear Implant Infection With <i>Escherichia coli</i> and <i>Bacteroides fragilis</i>

Cochlear implantation (CI) is a safe and well-established intervention for sensorineural hearing loss, with a low incidence of severe postoperative infections. We present the first reported case of cerebellar abscess and herniation due to CI infection. This unique case involves a 57-year-old man with recurrent cochlear implant infections, necessitating multiple debridements and eventual removal of the implant body while retaining the electrode array. This ultimately led to the formation of two right-sided cerebellar abscesses. His course was further complicated by cerebellar herniation due to mass effect, requiring urgent neurosurgical intervention and extensive antimicrobial therapy. Despite the grave prognosis, timely intervention led to significant clinical improvement. This case highlights the pathophysiology, implicated organisms, and management of cerebellar abscesses following CI/explantation, underscoring the importance of early recognition, aggressive infection control, and multidisciplinary management in this rare but serious complication.