Giant Petrous Segment Aneurysm Causing Facial Palsy: Case Report

Abstract

Objectives: Co-occurance of aneurysm causing facial palsy by compression and fibrous dysplasia.

Background: The aim of this study is to acknowledge this condition due to its rare frequency.

Methods: We report a case of a 54 year old patient presenting with sporadic right hemifacial spasms, lasting up to a minute. In 2023 it evolved with facial palsy House Brackmann V and episodes of headache. Imaging investigation showed a giant petrous segment aneurysm on the right internal carotid artery, with signs of aneurysm thrombosis, compression of the internal acoustic meatus and fibrous dysplasia of the temporal bone as well as erosion in the petrous apex. In our case embolization with coils was proposed.

Results: Petrous segment aneurysms are rare, so is fibrous dysplasia. The majority of cases is asymptomatic although they might cause hypoacusis, tinnitus, otorrhagia and epistaxis if located in proximity to the medium ear. Ruptured cases do not present with subarachnoid hemorrhage but Horner’s syndrome and symptoms of the jugular foramen nerves. The involvement of the VII nerve is not common. About the fibrous dysplasia, it is characterized by fibrous tissue replacement of normal bone. The temporal bone is affected in 18% of cases. Current treatment options for those aneurysms include carotid artery balloon occlusion, embolization with coils, remodelling with stents or conservative management by serial imaging exams.

Conclusion: Although compression of the VIIth-VIIIth nerve complex is uncommon for posterior fossa aneurysms it represents an important potential complication of vascular pathological features by disabling patients.