Continuous Ketamine Infusion as a Treatment for Refractory Facial Pain.

Complex orofacial pain disorders, such as trigeminal neuralgia (TN) and atypical facial pain (AFP), can be excruciating and debilitating during attacks. Ketamine, an N-methyl-D-aspartate (NMDA) antagonist, is a powerful analgesic that has been used to treat various chronic pain conditions, but its role in treating complex facial pain has only been recently explored. In this retrospective case series, we reviewed the efficacy of continuous ketamine infusion for 12 patients with facial pain refractory to medical treatment. Patients who presented with a diagnosis of TN were more likely to have significant and sustained pain relief after receiving ketamine infusion. By contrast, those who did not respond to the treatment were more likely to have a diagnosis of AFP. The current report suggests a fundamental difference between these two facial pain disorders in their respective underlying pathophysiology and supports the use of continuous ketamine infusion for refractory TN, but not AFP.