The association between vertebrobasilar dolichoectasia and hemifacial spasm.

Background: Hemifacial spasm (HFS) is frequently caused by vascular compression of the facial nerve. Vertebrobasilar dolichoectasia (VBDE) may cause vascular crowding in the limited space of the posterior fossa, increasing the chance of vascular compression of the facial nerve. We investigated the prevalence of VBDE in HFS.

Methods: We analyzed the presence of VBDE on 3.0 T magnetic resonance images in patients with HFS and control subjects; age, sex and hypertension were matched. Two blinded readers independently assessed the images. We evaluated the vascular risk factors, including diabetes mellitus, hyperlipidemia, ischemic heart disease, stroke, and presence of lacunes.

Results: A total of 310 patients with HFS and 310 control subjects were included. The prevalence of VBDE was higher in patients with HFS (48/310, 15.5%) than in controls (10/310, 3.2%), with an odds ratio (OR) of 5.82 (P < 0.001). Among patients with HFS, the presence of facial nerve compressing vessels was more frequent in dolichoectasia-positive patients (87.5%) than in dolichoectasia-negative patients (58.4%) (OR: 4.99, P < 0.001). Dolichoectasia-positive patients had a higher mean age (58.8 versus 54.8 years, P = 0.03), as well as greater frequency of hypertension (OR: 2.44, P = 0.01) and history of ischemic heart disease (OR: 5.05, P = 0.03) than their dolichoectasia-negative counterparts.

Conclusions: We found that VBDE is associated with HFS in a portion of patients. Since vascular risk factors were more prevalent in dolichoectasia-positive patients, an investigation of VBDE and its risk factors may serve to prevent vascular complications.