Thin‐slice T2 MRI imaging predicts vascular pathology in hemifacial spasm: A case‐control study

Abstract

Hemifacial spasm (HFS) is a condition that may severely reduce patients' quality of life. We sought to determine the sensitivity and specificity of thin-slice T2 magnetic resonance imaging (MRI) for detecting vascular compression in HFS patients. Prospective information was collected on 28 patients with HFS who presented to our center between March 2011 and March 2012 with thin-slice T2 MR imaging. The sensitivity and specificity for differentiating patients from controls were calculated. Sensitivities were 78.6% and 92.9% for the blinded radiologists and 75% for the partially blinded neurosurgeon. Specificities were 42.9% and 28.6% for the blinded radiologists and 75% for the partially blinded neurosurgeon. Magnetic resonance imaging of the facial nerve can guide clinicians in selecting patients who are good surgical candidates. Thin-slice T2 MRI should be viewed as supportive rather than diagnostic.

Magnetic Resonance Imaging Assessment of Vascular Contact of the Facial Nerve in the Asymptomatic Patient

“…19 Recently, Sekula et al evaluated the presence of vascular compression of the centrally myelinated portion of the facial nerve in a cohort of HFS patients. 13 They included a brief discussion of their control group of 28 asymptomatic patients in which there was imaging evidence of neurovascular compression of this vulnerable zone by an artery or vein in three and one control subjects, respectively. 13 Kakizawa et al performed an anatomical study of the facial nerve in 110 asymptomatic individuals using 3 T MRI and described a high rate of contact (78.6%) between the facial nerve and other structures (arteries, veins, dura mater, and other cranial nerves).…”

“…13 They included a brief discussion of their control group of 28 asymptomatic patients in which there was imaging evidence of neurovascular compression of this vulnerable zone by an artery or vein in three and one control subjects, respectively. 13 Kakizawa et al performed an anatomical study of the facial nerve in 110 asymptomatic individuals using 3 T MRI and described a high rate of contact (78.6%) between the facial nerve and other structures (arteries, veins, dura mater, and other cranial nerves). 20 However, their contact points were recorded based on distance from the TZ, as opposed to stratifying based on anatomic landmarks.…”

“…Previous reports evaluating preoperative MRI in patients undergoing microvascular decompression for HFS have shown varying degrees of interobserver variability as well. 9,12,13 However, it is important to make note that comparing studies is limited by the variability in the patient group being studied, MRI pulse sequences used, type and field strength of the MRI scanner, as well as the subjective nature of neurovascular compression rating by the radiologist or surgeon. Nevertheless, when reconciling the disagreement between neuroradiologists, the prevalence of facial nerve vascular contact in the non-HFS patient may be best estimated as a range of 37 to 53% in the current study.…”

“…6,8 Although investigators have studied the accuracy of different types of magnetic resonance imaging (MRI) sequences for identifying vascular loop compression preoperatively as compared with the gold standard of intraoperative findings during microvascular decompression for HFS, there is much less data to address the frequency with which a vessel is contacting or compressing the facial nerve as an incidental finding in the absence of a history of HFS. [9][10][11][12][13][14][15] The purpose of this study was to determine the prevalence of facial nerve vascular contact on MRI in patients without HFS.…”

MRI Findings in Patients with a History of Failed Prior Microvascular Decompression for Hemifacial Spasm: How to Image and Where to Look

“…[17][18][19][20] The use of SSFP imaging has been shown to predict vascular compression of the facial nerve with sensitivities of 75%-93% and specificities of 29%-75% for blinded observers. 21 In light of this higher sensitivity and lower specificity, the decision to operate is supported by imaging, but imaging results are never the sole factor in determining whether to offer MVD to a patient. Specifically, at our institution, an operation is typically not offered to a clinically unfavorable candidate even if imaging demonstrates vascular compression of the facial nerve.…”