Quantitative electromyographic characteristics of idiopathic unilateral vocal fold paralysis.

Unilateral vocal fold paralysis with no preceding causes is diagnosed as idiopathic unilateral vocal fold paralysis. However, comprehensive guidelines for evaluating the defining characteristics of idiopathic unilateral vocal fold paralysis are still lacking. In the present study, we hypothesized that idiopathic unilateral vocal fold paralysis may have different clinical and neurologic characteristics from unilateral vocal fold paralysis caused by surgical trauma. Retrospective, case series study. Patients with unilateral vocal fold paralysis were evaluated using quantitative laryngeal electromyography, videolaryngostroboscopy, voice acoustic analysis, the Voice Outcome Survey, and the Short Form-36 Health Survey quality-of-life questionnaire. Patients with idiopathic and iatrogenic vocal fold paralysis were compared. A total of 124 patients were recruited. Of those, 17 with no definite identified causes after evaluation and follow-up were assigned to the idiopathic group. The remaining 107 patients with surgery-induced vocal fold paralysis were assigned to the iatrogenic group. Patients in the idiopathic group had higher recruitment of the thyroarytenoid-lateral cricoarytenoid muscle complex and better quality of life compared with the iatrogenic group. Idiopathic unilateral vocal fold paralysis has a distinct clinical presentation, with relatively minor denervation changes in the involved laryngeal muscles, and less impact on quality of life compared with iatrogenic vocal fold paralysis. 4. Laryngoscope, 126:E362-E368, 2016.

Chang WH ，Fang TJ ，Li HY ，Jaw FS ，Wong AM ，Pei YC ... -  《-》

Distinct Disease and Functional Characteristics of Thyroid Surgery-Related Vocal Fold Palsy.

Tseng WC ，Pei YC ，Wong AM ，Li HY ，Fang TJ ... -  《-》

Disease Characteristics and Electromyographic Findings of Nonsurgery-Related Unilateral Vocal Fold Paralysis.

The detailed characteristics and prognosis of nonsurgery-related unilateral vocal fold paralysis (NSUVFP) are currently unclear. This study evaluated the extent of laryngeal nerve lesions and the individual characteristics for patients with NSUVFP. Retrospective, case series. Patients with unilateral vocal fold paralysis (UVFP) were evaluated using videolaryngostroboscopy and quantitative laryngeal electromyography. The side of nerve lesions, involvement of the external branch of the superior laryngeal nerve (eSLN), and complete vocal fold motion recovery were evaluated after ≥ 6 month follow-up. A total of 207 UVFP patients were recruited, including 153 surgery-related UVFP and 54 NSUVFP patients. Thirty-four (63%) and 20 (37%) NSUVFP patients were further assigned to idiopathic and nonsurgery-related-nonidiopathic (NSNI) groups, respectively. In the idiopathic group, eSLN lesions occurred in all six (100%) patients with right-side paralysis, but in only six of 28 (21%) patients with left-side paralysis (P < 0.001). The turn frequency of the paralyzed thyroarytenoid-lateral cricoarytenoid muscle complex is lower in the NSNI group (333.1 ± 192.1) compared with the idiopathic group (490.2 ± 255.1) (P = 0.02). The probability of complete vocal fold motion recovery did not differ among groups (P > 0.05). Idiopathic and NSNI UVFP have different clinical presentations defined by laryngeal electromyography. NSNI UVFP had more severe denervation changes compared with idiopathic UVFP. These results may support two pathogenic mechanisms for idiopathic UVFP: 1) neuropathy specifically involving left recurrent laryngeal nerve (RLN), and 2) neuropathy affecting nerves proximal to the RLN. 4. Laryngoscope, 127:1381-1387, 2017.

Pei YC ，Li HY ，Chen CL ，Wong AMK ，Huang PC ，Fang TJ ... -  《-》

Implications of Synkinesis in Unilateral Vocal Fold Paralysis.

Pei YC ，Chang WH ，Chuang HF ，Chang CF ，Fang TJ ... -  《-》

Cricothyroid muscle dysfunction impairs vocal fold vibration in unilateral vocal fold paralysis.

The relevance of the cricothyroid (CT) muscle in patients with unilateral vocal fold paralysis (UVFP) remains controversial. To clarify the functional significance of the CT muscle in patients with UVFP, the confounding effect of the severity of recurrent laryngeal nerve injury should be taken into consideration. In the present study, quantitative laryngeal electromyography (LEMG) was used to measure the severity of paralysis of the thyroarytenoid-lateral cricoarytenoid (TA-LCA) muscle complex to allow the functional contribution of the CT muscle to be determined. Cross-sectional study performed in an otolaryngology outpatient clinic. Thirty-one patients with a main diagnosis of UVFP were recruited. The main outcome measures included LEMG examination, quantitative LEMG analysis of the TA-LCA muscle complex, UVFP-related quality-of-life questionnaire (Voice Outcome Survey [VOS]), voice acoustics analysis, videolaryngostroboscopy, and general quality-of-life questionnaire (Short Form-36 Health Survey [SF-36]) assessments. The vocal cord position did not differ between patients with and without CT muscle impairment. Patients with both TA-LCA and CT paralysis showed poorer vocal fold vibration (P = .048) and higher fundamental frequency (P = .02), and the VOS and SF-36 were both poorer compared with patients with only TA-LCA paralysis. Although the vocal cord position was not influenced by CT muscle function, coexisting CT muscle paralysis may damage the voice by impairing vocal fold vibration in UVFP patients.

Pei YC ，Fang TJ ，Li HY ，Wong AM ... -  《-》