Restless mouth syndrome

A 60-year-old man was referred to our headache clinic for evaluation of atypical facial pain. He reported a 1-year history of oral discomfort that began 2 to 3 months after a fall with trauma to the posterior neck. He described an uncomfortable but nonpainful sensation of swelling and numbness at the roof of the mouth that gradually spread to the tongue, bilateral buccal surfaces, and eventually the whole mouth. This was particularly prominent when his mouth was in a relaxed open position and was associated with a strong urge to move his jaw. Movement of the jaw and tongue provided temporary relief. He chewed gum for hours at a time to alleviate the symptoms, although the relief was sometimes only partial or intermittent. Keeping the jaw completely closed or clenching the teeth also provided improvement in his symptoms. Thus, he used a headband, pillow, or hand to keep the jaw closed. His symptoms began midmorning and persisted throughout the day, but were worse in the evening. The symptoms did not interfere with sleep as long as he was able to keep his jaw closed with a pillow. He denied xerostomia or xerophthalmia. He had a history of basal cell carcinoma of the left cheek status post resection 2 to 3 years ago without residual numbness. He had no personal or family history of trigeminal neuralgia, headaches, neuropathy, or restless legs syndrome (RLS). He had no history of having been on neuroleptics, antiemetics, or other dopamine antagonists. Before seeing us, he tried abstaining from caffeine and spicy food, and tried cinnamon, increased hydration, and vitamin B12 without benefit. Trials of gabapentin 200 to 300 mg 3 times a day and pregabalin 200 mg twice a day also had not provided improvement. Oxcarbazepine, at an unknown dose, was ineffective and associated with anxiety and nervousness.