title: Vascular tortuosity in relationship with hypertension and posterior fossa volume in hemifacial spasm.
abstract: BACKGROUND
  Hemifacial spasm (HFS) is a disabling neurological condition. Vascular tortuosity in HFS patients has not been quantified objectively and its relationship with hypertension and posterior fossa volume (PF) is unknown. In a case control magnetic resonance imaging and angiographic (MRI/A) study, we quantified and compared the vascular tortuosity in HFS and controls, and evaluated its relationship with hypertension and PF.
  
  
  METHODS
  Using a commercially available vessel probe tool, an index of tortuosity based on vessel over chord length was employed to quantify vascular tortuosity of the vertebral (VA) and basilar arteries (BA) in 79 subjects (40 HFS, 39 controls).
  
  
  RESULTS
  The tortuosity index of the BA (1.09 vs 1.16, p = 0.26, 95 % CI 1.07, 1.23), RVA (1.15 vs 1.15, p = 0.83, 95 % CI 1.06, 1.38) and LVA (1.14 vs 1.288, p = 0.16, 95 % CI 1.14, 1.44) was not different between HFS and controls, with adjustments for PF volume and hypertension.
  
  
  CONCLUSIONS
  Contrary to popular belief, our study showed that taking into account hypertension and PF volume, vascular tortuosity of the vertebrobasilar arteries is unlikely to be a major etiologic factor in HFS, though its role in select individuals cannot be excluded. The complex interplay of facial nerve hyperexcitability, genetic predisposition, vascular tortuosity, posterior fossa volume and hypertension needs to be further evaluated.
authors.affiliation: Department of Diagnostic Radiology, Singapore General Hospital, Singapore, 169608, Singapore.|Oxford Medical School, Oxford, UK.
authors.forename: Evan Cyril
authors.initials: EC
authors.lastname: Edmond
authors.affiliation: Department of Diagnostic Radiology, Singapore General Hospital, Singapore, 169608, Singapore.|Duke NUS Graduate Medical School, Singapore, 169857, Singapore.
authors.forename: Samantha Xue-Li
authors.initials: SX
authors.lastname: Sim
authors.affiliation: Health Services Research and Biostatistics Unit, Division of Research, Singapore General Hospital, Singapore, 169608, Singapore.
authors.forename: Hui-Hua
authors.initials: HH
authors.lastname: Li
authors.affiliation: Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore, 169608, Singapore.|Duke NUS Graduate Medical School, Singapore, 169857, Singapore.
authors.forename: Eng-King
authors.initials: EK
authors.lastname: Tan
authors.affiliation: Department of Diagnostic Radiology, Singapore General Hospital, Singapore, 169608, Singapore. chan.ling.ling@singhealth.com.sg.|Duke NUS Graduate Medical School, Singapore, 169857, Singapore. chan.ling.ling@singhealth.com.sg.
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Chan
mesh_terms: D000328:Adult; D000368:Aged; D001808:Blood Vessels / Q000473:pathology*; D001921:Brain / Q000473:pathology; D005260:Female; D019569:Hemifacial Spasm / Q000150:complications / Q000473:pathology*; D006801:Humans; D006973:Hypertension / Q000150:complications; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged
keywords: Hemifacial spasm; Imaging; Tortuosity