Delayed facial nerve palsy secondary to a middle ear blood clot: a case report

Background: Delayed facial nerve palsy (FNP) is a rare complication of temporal bone trauma. It is typically associated with fractures of the petrous bone and compression of the facial nerve within the fallopian canal. Case presentation: We report an unusual case of delayed-onset FNP occurring in association with a middle ear blood clot after temporal bone trauma, without radiological or intraoperative evidence of facial canal dehiscence. The patient was an 18-year-old male admitted following road trauma associated with a transverse fracture of the left petrous apex and otorrhagia. After about 3 weeks, due to persistent symptoms and radiological findings, the patient underwent a tympanotomy revealing an organized blood clot within the middle ear cavity adjacent to the tympanic segment of the facial canal. After blood clot evacuation, the patient experienced rapid recovery. This case suggests that a middle ear blood clot may be considered among the possible factors associated with delayed facial nerve palsy, even in the absence of radiological or intraoperative evidence of facial canal dehiscence. Although a causal relationship cannot be established, the anatomical proximity of the tympanic segment to the middle ear cavity raises the hypothesis that extrinsic effects on the nerve’s microvascular supply (vasa nervorum) may contribute to transient dysfunction. Conclusion: This case suggests that a middle ear blood clot may represent a possible contributing factor in selected cases of delayed FNP after temporal bone trauma, even when imaging shows no evidence of facial canal dehiscence. In selected cases, surgical evacuation may result in recovery. However, a causal relationship cannot be definitively established from a single case report.