NEURALGIA DE ARNOLD
It is estimated that in approximately 15% of the patients the trigeminal neuralgia is secondary to an intracranial abnormality.(1) Thus, all patients must be evaluated with MRI.(2) Although a rare association, trigeminal neuralgia may be caused by multiple sclerosis.(1-3) The Figure shows a brain MRI of a 49-yearold woman with left V3 trigeminal neuralgia caused by multiple sclerosis. The MRI is demonstrating a demyelinating lesion at the left trigeminal root entry zone (arrow).