Vascular compression of the trigeminal nerve is a frequent finding in asymptomatic individuals: 3-T MR imaging of 200 trigeminal nerves using 3D CISS sequences.

BACKGROUND: The aim of this study was to assess whether individuals without symptoms of trigeminal neuralgia exhibit vascular compression of the trigeminal nerve. This was investigated using ultra-high-field MR imaging.

METHODS: One hundred subjects were imaged using a 3-T magnet and high-spatial-resolution three-dimensional (3D) MR imaging with 3D constructive interference in steady-state sequences.

FINDINGS: Neurovascular compression (NVC) was detected in 92 of the individuals, with 83 cases bilateral and 9 unilateral. In total, 175 (87.5%) of the 200 nerves examined showed NVC. In 58% of the affected individuals, the vessel was compressing a site in the proximal third of the trigeminal nerve. Eighty-six percent of the compressing vessels were arteries, and 14% were veins.

CONCLUSIONS: Ours is the first study to have evaluated NVC of the trigeminal nerve in asymptomatic individuals using 3-T MR imaging. The high prevalence of compression we observed is close to rates of NVC that have been documented in large series of microvascular decompression for trigeminal neuralgia. Our findings strongly suggest that vascular compression of the trigeminal nerve is not necessarily pathological.