Abstract: Objective To observe the clinical efficacy of botulinum toxin typeA(BTX-A) in the treatment of palatal myoclonus objective tinnitus(PMOT)under the guidance of palatal electromyography(P-EMG). Method The clinical data of 3 bilateral PMOT patients were reviewed. With endoscopic assistance, the disposable hypodermic needle electrode was inserted at the initiation site of tensor veli palatine(TVP), levator veli palatine(LVP), and termination site of LVP through nasal cavity. The direction and depth of the electrodes were adjusted according to the denseness of electric potential outbreak in the EMG diagram d. The superficial site, with the most dense electric potential outbreak was chosen as the point for injection. At each point, 5U BTXA was injected every time and the total amount was 30U . The therapeutic effects and adverse reaction were observed for 6 months afterthe injection. Result ① Therapeutic effectiveness: The PMOT was disappeared 26 h, 25 h and 28 h after the injection in 3 patients, respectively. None of positive expressions was observed in monthly endoscopic examination, P-EMG, and acoustic immittance examination 5 months after the injection. Recurrence of unilateral tinnitus was noted in only one patient.② Adverse reaction :The side effects, such as open rhinolalia, mild nasal regurgitation and mild ear stuffiness with tinnitus, were identified, but disappeared 2 weeks later afterthe treatment. Conclusion Using P-EMG during BTXA injection can accurately determine the site for injection, extend the action time of BTXA, reduce the adverse reaction, and achieve a good clinical results.

Key words: Tensor veli palatine, Palatal electromyography, Levator veli palatine, Botulinum toxin typeA, Palatal myoclonus objective tinnitus