METHODS: The authors reviewed 1642 cases of HFS. Assessments were based on clinical
features, 3-dimensional time-of-flight magnetic resonance angiography, and surgical
findings. Causes other than neurovascular compression at the root exit zone of the facial
nerve were investigated and unusual clinical presentations were noted. RESULTS: Nine
(0.5%) patients had a secondary causative structural lesion, 7 patients had a tumor, and the
remaining 2 had a vascular malformation. Direct compression by dolichoectatic …