An unusual case of neglected CSOM presenting with perineural spread along seventh/eighth cranial nerves to form cerebellar peduncle abscess: A case report

Chronic suppurative otitis media (CSOM) is a common otologic disorder that may occasionally result in intracranial complications. However, extension of infection into the posterior cranial fossa through the facial (VII) and vestibulocochlear (VIII) nerve complex is exceedingly rare. We report the case of an 18-year-old male with a 7-year history of neglected bilateral ear discharge, hearing impairment, and left-sided lower motor neuron facial nerve palsy who presented with severe headache, vomiting, and seizures. Contrast-enhanced magnetic resonance imaging (MRI) demonstrated findings consistent with labyrinthitis, with contiguous enhancement involving the labyrinth, the VII/VIII cranial nerve complex, and the left middle cerebellar peduncle, where an abscess had developed. High-resolution computed tomography (HRCT) of the temporal bone revealed features of advanced CSOM, extensive osseous destruction, labyrinthine fistula formation, and labyrinthitis ossificans. Notably, no defect was identified in Trautmann’s triangle. In the absence of alternative pathways of intracranial extension, perineural spread along the facial and vestibulocochlear nerves was considered the most plausible mechanism of infection dissemination. This case highlights a rare route of intracranial spread of otogenic infection through the VII/VIII cranial nerve complex, culminating in cerebellar peduncle abscess formation. Awareness of this uncommon pathway is important for early diagnosis and management of atypical intracranial complications of CSOM.