Vascular Loop Compressing Facial Nerve in Hemifacial Spasm : Demonstrated by 3D-phase Contrast Magnetic Resonance Angiography in 101 Patients
SUTHISUK SUTHIPONGCHAI, MD*, ORASA CHAWALPARIT,MD*, ANCHALEE CHUROJANA, MD*, NIPHON POUNGVA RIN, MD**
Affiliation : *Department of Radiology, **Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
Purpose : To determine the vascular loop compression of the facial nerve in patients with hemifacial spasm by 3D-phase contrast (PC) magnatic resonance imaging (MRI).
Materials and Methods : A retrospective study of 101 patients with hemifacial spasm who went MRI and magnetic resonance angiography (MRA) of the brain was done. The magnitude images of the 3D-PC MRA was evaluated in axial and oblique coronal reconstruction planes blindly from symp tomatic information.
Results : Among 101 patients, 53 affected the left side, 48 patients were right sided and none had bilateral involvement. Vascular loop compressing on the symptomatic side was found in 61 (60.4%) patients. For the asymptomatic side, there were 14 (13.86%) with vascular loop contact. Five patients (4 . 9%) had bilateral vascular compression. The proportion of vascular contact of the symptomatic and asymptomatic side was significantly different (with p < 0.001). The offending vessels were vertebral artery (32, 52.46%), posterior inferior cerebellar artery (7, 6.93%), anterior inferior cerebellar artery (6, 5.94%) and artery of uncertain origin (16, 26.23%).
Conclusion : The study implied the usefulness of this simple technique to demonstrate the neurovascular contact of the facial nerve.
Keywords : Hemifacial Spasm, MRI, Diagnosis, Vascular
