Laryngeal muscle activity in unilateral vocal fold paralysis patients using electromyography and coronal reconstructed images.
OBJECTIVE
To assess laryngeal muscle activity in unilateral vocal fold paralysis (UVFP) patients using laryngeal electromyography (LEMG) and coronal images.


METHODS
Case series with chart review.


METHODS
University hospital.


METHODS
Twenty-one patients diagnosed with UVFP of at least 6 months in duration with paralytic dysphonia, underwent LEMG, phonatory function tests, and coronal imaging. A 4-point scale was used to grade motor unit (MU) recruitment: absent = 4+, greatly decreased = 3+, moderately decreased = 2+, and mildly decreased = 1+. Maximum phonation time (MPT) and mean flow rate (MFR) were employed. Coronal images were assessed for differences in thickness and vertical position of the vocal folds during phonation and inhalation.


RESULTS
MU recruitment in thyroarytenoid/lateral cricoarytenoid (TA/LCA) muscle complex results were 1+ for 4 patients, 2+ for 5, 3+ for 6, and 4+ for 6. MPT was positively correlated with MU recruitment. Thinning of the affected fold was evident during phonation in 19 of the 21 subjects. The affected fold was at an equal level with the healthy fold in all 9 subjects with MU recruitment of 1+ and 2+. Eleven of 12 subjects with MU recruitments of 3+ and 4+ showed the affected fold at a higher level than the healthy fold. There was a significant difference between MU recruitment and the vertical position of the affected fold.


CONCLUSIONS
Synkinetic reinnervation may occur in some cases with UVFP. MU recruitments of TA/LCA muscle complex in UVFP patients may be related to phonatory function and the vertical position of the affected fold.
Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kumamoto University, Kumamoto, Japan.
Tetsuji
T
Sanuki
Eiji
E
Yumoto
Kohei
K
Nishimoto
Ryosei
R
Minoda
D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D004576:Electromyography / Q000379:methods*; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D015994:Incidence; D007564:Japan; D007821:Laryngeal Muscles / Q000503:physiopathology*; D007828:Laryngoscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods; D014826:Vocal Cord Paralysis / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy; D055815:Young Adult
CT images; laryngeal electromyography; synkinesis; unilateral vocal fold paralysis