[Study of neurovascular contact in essential hemifacial spasm: an example of CISS sequence and magnetic resonance angiography].
OBJECTIVE
The purpose of this article is to assess the validity of the magnetic resonance imaging (MRI) CISS 3D sequence associated with 3D time of flight (TOF) angiographic sequence in order to detect neurovascular contact (NVC) between the facial nerve and neighbouring arteries in patients with essential hemifacial spasm (HFS) and to determine the relationship between HFS symptoms and NVC and NVC image features (type, number and site).


METHODS
We prospectively enrolled 120 cerebellopontine angle (CPA) MRI studies, 44 cases with HFS symptoms and 76 which were asymptomatic (controls), using axial T2-weighted (CISS) and axial 3D TOF series with associated Maximal intensity (MIP) reconstructions. Prior TOF angiographic studies were available for 56 cases without associated CISS images and the results obtained from that study were compared with the results of the current study.


RESULTS
The diagnostic values obtained significantly favoured the protocol used in this study, which demonstrated a sensitivity of 77.27% and a specificity of 75%. There was a statistically significant relationship between the presence of NVC and HFS symptoms (p<0.0001). Only one statistically significant relationship was found between facial nerve displacement (in type of NVC) and HFS symptoms (p=0.019).


CONCLUSIONS
The proposed MRI protocol is sensitive and valid for detecting NVC in patients with HFS. The results of our study support a relationship between NVC and HFS symptoms. It is not a simple relationship, however. It may be influenced by other factors, such as displacement of the facial nerve due to NVC.
Gorriño Angulo
M
M
Departamento de Radiología, Hospital Galdakao-Usansolo, Galdakao, Bizkaia, España. mgorri@seram.org
Sádaba Garay
F
F
Oleaga Zufiria
L
L
Gorriño Angulo
O
O
Gómez Muga
J J
JJ
Bermejo Espinosa
N
N
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001158:Arteries / Q000033:anatomy & histology / Q000473:pathology*; D005154:Facial Nerve / Q000098:blood supply / Q000473:pathology*; D005260:Female; D019569:Hemifacial Spasm / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods / Q000592:standards; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity