Palatal myoclonus responding to carbamazepine

We recently observed a rare example of palatal myoclonus occurring in the setting of active central nervous system syphilis with tabes dorsalis. The woman had been well until May, 1979, when she developed a sudden period of unconsciousness that lasted for several hours and was followed by amnesia, euphoria, and uncontrolled logorrhea. Attacks of involuntary movements affecting the lower jaw, tongue, and pharynx began six weeks later, occurring ten to twenty times a day and lasting 10 to 20 seconds each. On examination she was alert, euphoric, and demented. She had Argyll Robertson pupils and a continuous, rhythmic contraction of the soft palate bilaterally with a frequency of 120 to 200 per minute. Paroxysms of rhythmic contractions of the posterior pharyngeal wall, tongue, and lower jaw appeared intermittently. Both these involuntary movements were observed during sleep. Laboratory data showed a positive serological test for syphilis and Treponema pallidum hemagglutination titer in the blood, the latter in a dilution of 5,120. The cerebro-