Altered cutaneous sensation in trigeminal neuralgia.

Noninvasive quantitative somatosensory tests were used to measure sensory perception thresholds on the faces of 26 patients with idiopathic trigeminal neuralgia. The affected divisions were determined by the presence of trigger zones. Elevations of thresholds of sensations subserved by both large- and small-diameter fibers were found both in the affected and in the unaffected adjacent divisions when compared with the healthy side. The findings are interpreted as further evidence of combined peripheral and central pathologic conditions in idiopathic trigeminal neuralgia.