Voice therapy for abductor spasmodic dysphonia (ABSD) A case report

A 24-year-old female patient with abductor spasmodic dysphonia (ABSD) was treated by voice therapy with successful results. Vocal symptoms including intermittent aphonia and prolonged voiceless consonants were exhibited in tandem with a rise in pitch during speech, but were reduced when talking at lower pitch. Voice therapy was targeted toward reduction of the vocal symptoms by lowering the pitch to within an acceptable range considering the patient's age and sex. Two target pitches, G3 (196 Hz) and B3 (247 Hz), were selected because the Japanese language makes use of two levels of pitch, high and low, within a word. The new pitches were facilitated by working on single words, short sentences, and passages. Subsequent carryover sessions focusing on practice in actual conversation were added. The results of the treatment were satisfactory, and spectrographic data were compatible with our clinical impression. Six professionals evaluated the patient's recorded voice (54 words, 176 morae) using the mora method. The number of morae impaired by vocal symptoms was 82.5 before treatment and 14.5 after. These findings suggest the possibility that the vocal symptoms of ABSD in this case are caused by abnormalities of the cricothyroid (CT) muscle, because lowering of pitch had positive effects on the patient's voice.