Endoscopic microvascular decompression for hemifacial spasm associated with an enlarged jugular tubercle: A case report

Background: Hemifacial spasm (HFS) is a clinical syndrome associated with motor dysfunction of the facial nerve as a result of conflict with surrounding vessels. Narrowing of the cerebellopontine angle (CPA) cistern by the abnormality of its bony boundaries has been postulated to increase the risk of such neurovascular conflict (NVC). Case Description: We present a case of a 61-year-old man with clinical features of a right-sided HFS of 1-year duration. Brain magnetic resonance imaging and computed tomography angiography with 3D fusion images revealed compression of the right CNVII by a loop of the anterior inferior cerebellar artery at the root entry zone. There was also a finding of an enlarged jugular tubercle causing narrowing of the cerebellopontine cistern, which we postulated to be the underlying cause of the NVC. He had endoscopic keyhole microvascular decompression with resolution of symptoms. Conclusion: Bony enlargement of the jugular tubercle or other bony structures in the CPA could narrow the cerebellopontine cistern and bring the nerve and blood vessels into closer proximity, potentially increasing the incidence of NVC.