Facial pain in a case of cranial dystonia: a case report

A 76-year-old man had shown sustained excruciating facial pain in the maxil lary region for more than 30 years. Since he was suffering from blepharospa sm, facial electromyography was performed and revealed a perioral dystonia. This possible cause of facial pain might have been overlooked had dystonia not been considered and electromyographical studies performed. Repeated in tramuscular perioral injections of botulinum toxin brought about complete p ain relief. This case shows that involuntary activity of facial muscles can cause a severe chronic pain syndrome. Possible mechanisms include irritati on of ascending trigeminal fibers, muscle ischemia due to compression of bl ood vessels, or release of pain-producing substances.