The aim of this thesis is to improve evidence of efficacy and side effects in existing treatment therapies for difficult to treat patients with trigeminal neuralgia and to unveil new targets of treatments.

In study I, we evaluated the efficacy and side effects of intravenous fosphenytoin treatment. We found that 60% of the patients had at least a 50% reduction in pain intensity 24 hours after infusion, and that the pain intensity was still significantly reduced on day 7. This treatment provides a time window for titration of other TN medications or refer to neurosurgery. This study provides better evidence for its rightful place amongst rescue medication.

In study II we used a state-of-the-art methodology with independent assessors of outcome and complications after MVD in a 2-year follow-up period. We found that 86% of the patients had a clinically significant outcome. Due to the risk of complications, further optimization of patient selection is needed. 

In study III we conducted a randomized, placebo-controlled trial investigating whether erenumab,

an antibody against the CGRP receptor, can relieve TN. We found that erenumab did not

reduce either pain intensity or the number of paroxysms in TN patients. These results indicate that TN pain is independent of the CGRP-signalling pathway​