Multiple Sclerosis and Trigeminal Neuralgia: A Two-Hit Hypothesis

Trigeminal neuralgia (TN) occurs in 2% to 5% of patients with multiple sclerosis (MS). The cause is thought to be a demyelinating plaque within the root entry zone of the pons. Investigators used magnetic resonance imaging (MRI) to determine what proportion of patients with MS-associated TN had neurovascular compression of the nerve.

More than 1500 MS patients were screened to find 37 with TN, with 28 included in the study. Participants underwent 3T MRI with fine cuts through the brainstem and time-of-flight MR angiography. MRI scans detected a demyelinating plaque in the pons on the TN-affected side within 26 of 28 patients. However, 17 of the 28 patients (15 of the 26 with pontine plaque) appeared to have neurovascular compression of the t…