TN: trigeminal neuralgia; MRI: magnetic resonance imaging; MRA: magnetic resonance angiography. * Refer to UpToDate text for details of MRI and MRA sequences. ¶ Morphological change includes dislocation, distortion, and/or atrophy of the trigeminal nerve root. Δ Mere contact without morphological change can be innocuous, but surgery may reveal compression or other morphological change not detected by MRI.
