Trigeminal neuralgia and the merit of small clinical trials

Trigeminal neuralgia is a severe chronic neuropathic pain condition characterised by paroxysmal pain in a region of the face corresponding to one or more divisions of the trigeminal nerve.1 Available treatments are not always effective and can be associated with intolerable side-effects.2 In trigeminal neuralgia, and in neuropathic pain in general, available drugs have all been identified through empirical clinical observations, whereas investigational drugs identified through bottom-up translational approaches have not been efficacious in clinical trials.