الفهرس 
Neuroanatomy of Laryngeal InnervationOnly 14 pages are availabe for public view
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Abstract
Unilateral vocal fold paralysis represents one cause of the organic dysphonia. The patient presents with paralytic dysphonia of breathy character and aspiration of food and fluid. Assessment of the patient include three main lines; elementary diagnostic procedures, clinical diagnostic aids and additional diagnostic instrumental measures. Treatment includes two main lines; behavioral readjustment voice therapy and surgery. Surgical treatment should not be undertaken before 6 – 12 months after the onset of paralysis. During this period, voice therapy should be tried. However, in specific cases where spontaneous recovery could not be expected, surgical treatment can be performed as early as possible as in purposeful resection of the recurrent laryngeal nerve along with thyroid carcinoma or tumor of the upper third of the esophagus. In historical order, treatment of unilateral vocal fold paralysis included vocal fold injection, laryngeal framework surgery (thyroplasty type I and arytenoid adduction) and reinnervation surgery (nerve-muscle pedicle transfer and ansa cervicalis to recurrent laryngeal nerve anastomosis). Combinations of the laryngeal framework and reinnervation surgeries were tried in the last few decades.
The aim of this study is to compare among voice outcomes following arytenoid adduction alone (group I) and arytenoid adduction combined with thyroplasty type I (group II), with nerve-muscle pedicle transfer (group III) and with ansa cervicalis to recurrent laryngeal nerve anastomosis (group IV). This study included 46 subjects; 11 subjects in group I, 13 in group II, 13 in group III and 9 subjects in group IV. Voice evaluation was carried out preoperatively and after 3, 12 and 24 months postoperatively. Voice parameters evaluated are GRBAS (grade overall and breathiness), mucosal wave vibration pattern, jitter, shimmer, harmonics-to-noise ratio, pitch perturbation quotient, amplitude perturbation quotient, maximum phonation time, mean flow rate, fundamental frequency, intensity and pitch range. Results revealed that voice outcomes vary greatly from a group to another. In group I, only six out of the 12 parameters evaluated repeatedly improved after 3 months. This improvement did not continue after 3 months and voice changes pattern was random over time. Also, the mucosal wave vibration pattern (3 parameters) did not reveal any postoperative improvements apart from the glottal gap area. In group II, 11 parameters showed significant improvement after 3 months which become stationary later on with no further significant improvement over time apart from the mean flow rate. In addition, the 3 mucosal wave parameters significantly improved in this group. In group III, all voice parameters with repeated measurements (n = 12) improved significantly not only after 3 months but also continued to improved steadily over time apart from jitter. Moreover, the mucosal wave vibration pattern was markedly improved in this group. Lastly, group IV revealed significant improvement in voice after 3 months in 10 parameters with further improvement over time in 8 parameters. In addition, mucosal wave vibration pattern showed good postoperative improvement. from these results, it can be concluded that voice outcomes showed better results following combined arytenoid adduction with any of the reinnervation techniques than following arytenoid adduction with or without thyroplasty type I. This can be explained by the ability of these methods to restore the tensing capability of the thyroarytenoid muscle which is necessary for obtaining symmetrical vocal folds mass and tension. This symmetry is essential for normal mucosal wave vibration and propagation during voice production. On the other hand, the combined arytenoid adduction corrects the VF vertical level difference and puts the VF in the midline. Therefore, these combined techniques can fulfill the pre-requisites for normal voice production.
Pattern of voice outcome following AA combined with reinnervation procedures (AA + AC-RLN and AA + NMP) is not only improved at 3 months after surgery, but also continued to improve steadily over the 2 years of the study. These steady improvements were evident in most voice parameters in these treatments. Also, the perceptual voice quality showed excellent improvement especially in the long-term results only in the AA combined with reinnervation procedures with normal or near-normal voice in most cases. Furthermore, the mucosal wave vibration pattern showed markedly improved outcome after surgery with significant differences compared to the control group. Such pattern of voice outcomes did not occur in the AA or AA + I procedures. Results revealed that AA + NMP offered the best voice outcome followed by AA + AC-RLN, then AA + I and finally AA only.