Vocal Vibration Opening Onset Position Abnormality in Patients With Adductor Spasmodic Dystonia by Using High-Speed Endoscopy.

OBJECTIVE

To analyze vocal fold vibration onset in patients with adductor laryngeal dystonia (ADLD) by analyzing vocal vibration opening onset position (VVOOP).

STUDY

DESIGN

Case-control study

SETTING

A voice center.

METHODS

Eleven patients with ADLD diagnosed in our voice center were enrolled in the ADLD group. Eleven healthy subjects matched by exact age and gender to the ADLD patients were selected as the control group. All subjects underwent laryngeal high-speed video endoscopy. VVOOP and its change were assessed by two otolaryngologists. The multiline video kymography was used to analyze the open quotient (OQ) and standard deviation of OQ.

RESULTS

VVOOP had more than one position in 54.6% (6/11) of the patients with ADLD, which was higher than the control group (P < 0.05). VVOOP appeared in the front of the vocal fold in 54.6% (6/11) of patients with ADLD and in the back of the vocal fold in 81.8% (9/11) of patients with ADLD. VVOOP can be abnormal in 90.9% (10/11) of patients with ADLD, and the rate of VVOOP abnormality was higher than that of the control group (P < 0.05). Of 11, 6 (54.6%) patients with ADLD had a variable VVOOP; the variability rate of VVOOP was higher than that in the control group (P < 0.05). OQ and OQ standard deviation in the ADLD group were significantly greater than in the control group (P < 0.05).

CONCLUSIONS

In patients with ADLD, vocal fold vibration was irregular, and VVOOP was abnormal and had a variable position and could reflect variability of the vocal vibration.

LEVEL OF EVIDENCE: Level 4.