Features of muscle tension dysphonia before and after correction of unilateral vocal cord paralysis.

Objective: We performed a retrospective, longitudinal study to compare the prevalence of hyperkinetic laryngeal features before and after successful correction in patients with unilateral vocal cord paralysis (UVCP).

Methods: Eighty-six patients with UVCP who had a successful surgical correction were enrolled. Preoperative and post-operative videolaryngostroboscopy images were analyzed, and the muscle tension patterns (MTPs) were rated according to the Morrison-Rammage classification. A 4-item glottal closure index was used for each patient on study entry and for 40 normal subjects as the control group.

Results: There was no significant difference in MTP prevalence before (57%) and after (55%) surgical correction for UVCP. Although the glottal closure symptoms were tremendously improved through surgical medialization for UVCP, they persisted and were more prevalent than those in normal individuals.

Conclusions: Persistence of MTPs after correction of UVCP may be due to intractable vocal habits or psychogenic factors.