SUPRAGLOTTAL INJECTION OF BOTULINUM TOXIN TYPE-A IN ADDUCTOR TYPE SPASMODIC DYSPHONIA WITH BOTH INTRINSIC AND EXTRINSIC HYPERFUNCTION

Patients with adductor type spasmodic dysphonia (SD) often exhibit bot h glottal and supraglottal hyperfunction. Based on the hypothesis that a ''ventricular muscle'' may contribute to the hyperfunction in these cases, eight patients with adductor type SD were treated with bilater al injection of botulinum toxin type A into the ventricular folds, Fou r weeks after injection, ventricular fold hyperfunction was absent in all cases. Number of voice breaks, standard deviation of fundamental f requency, and shimmer were significantly improved, Voice range profile s of the speaking voice were significantly extended in dynamic and fre quency range, Side effects were a breathy phonation and mild swallowin g difficulties without aspiration for about 1 week, Patients' self-rat ing concerning strangled and breathy voicing demonstrated an interval of acceptable voice quality between 1 week and 4 months after injectio n in all cases, Results suggest that supraglottal injection in patient s with SD of both glottal and supraglottal hyperfunction, as a new app roach, can normalize supraglottal activity and improve glottal voicing , Based on our experience with other patients with adductor type of SD , this injection technique is as efficient as injection into the thyro arytenoid muscle, Nevertheless, it remains to be proved that a patholo gic ventricular muscle activity is addressed by this technique or if i t is based on spreading to the thyroarytenoid muscle.