Patulous Eustachian Tube and Otitis Media With Effusion as Complications After Trigeminal Nerve Injury

Abstract

To describe three patients of patulous Eustachian tube (pET) after trigeminal nerve injury and to demonstrate for the first time their magnetic resonance imaging (MRI) findings to hypothesize the mechanism of the pET after trigeminal nerve injury. Three patients presented with autophony after trigeminal nerve injury caused by the removal of intracranial tumors. Clinical patient records, audiological data, and MRI. Each patient initially developed transient otitis media with effusion (OME) within a few months after surgery and subsequently developed pET. The MRI of the three patients when they developed pET demonstrated atrophy and fat infiltration of the muscles innervated by the mandibular branch of the trigeminal nerve. All three patients transiently manifested OME before pET was diagnosed. Based on the MRI findings and anatomical considerations, this chronological transition from OME to pET was speculated as an initial motor paralysis of the tensor veli palatini muscle, followed by volume decrease of the muscles in the vicinity of the ET due to denervation atrophy and fat infiltration, which resulted in ET closing failure.