A clinical comparison of trigeminal neuralgic pain in patients with and without underlying multiple sclerosis.

Despite clinical similitude, there is a tendency to consider trigeminal pain in multiple sclerosis (MS) as a distinct condition. To evaluate clinical differences in trigeminal pain presentation in patients with and without underlying MS, we compared clinical characteristics of facial pain found in 15 consecutive MS patients with those reported by 13 consecutive subjects diagnosed with classical trigeminal neuralgia. The only significant difference between MS and non-MS neuralgic patients was the age of onset of pain (43.4+/-10.5 in MS vs. 59.6+/-11.50 in non-MS patients, p=0.000629, unpaired Student's t-test). No differences were observed for side, duration and quality of pain, trigeminal branches involved, presence of trigger areas or factors, pain refractive period, remitting-relapsing or chronic course. There was only a trend without statistical significance in interval pain and trigeminal hypoesthesia, more frequent in MS population. Only one patient in the MS group presented with long-lasting episodes (45-60 min) of atypical odontalgia. Our findings support the view of a common pathogenetic mechanism underlying TN in the two groups, possibly related to demyelination of the trigeminal entry root in the pons. Typical TN in MS patients should be considered as "symptomatic trigeminal neuralgia".