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The objective of this study was to improve the evaluation of unilateral vocal fold paralyses (uVFP) by means of an area measurement of the glottic plane, which describes the position of the paralysed vocal fold. The area measurements were related to electromyographic findings and clinical outcome (recovery, voice quality). In 56 patients (33 women and 23 men), uVFP were confirmed by endolaryngeal electromyography (EMG) of the paralysed vocal fold and cricothyroid muscles (CT). The EMG response was classified on a 4-point scale (from 0 to 3). Vocal fold position was divided into 'paramedian' and 'intermediate' and additionally quantified by measurement of the glottic area. An 'area quotient' (AQ) was calculated and related to the EMG findings and clinical outcome. Voice qualities were objectified regarding their additive noise (breathiness) and irregularity (roughness) using the 'Göttingen Hoarseness Diagram'. The majority of uVFP was due to iatrogenic lesions. The AQ of classically graduated 'paramedian' and 'intermediate' vocal fold positions was significantly different but did not correlate with objective voice quality values. There were no significant correlations regarding EMG findings, duration or recovery from paralyses. Laryngeal EMG remains the gold standard for verifying uVFP. But EMG did not correlate significantly with AQ or functional outcome of uVFP. The measurement of an AQ is suitable for obtaining continuous data describing the position of paralysed vocal folds beyond the terms 'paramedian' or 'intermediate' and provides the basis for clinical evaluations of diagnostic tools and therapeutic interventions.

Objectives: We performed a prospective study to assess respiratory function and voice quality before and after laser microsurgical bilateral posterior cordectomy performed for chronic airway obstruction in patients with bilateral vocal fold paralysis., Methods: In 17 patients a laser microsurgical posterior cordectomy was performed as an immediate bilateral approach. Roughness, breathiness, hoarseness, and dyspnea were evaluated both subjectively (on a scale from 0 to 3) and objectively (body plethysmography, computerized voice analysis: Göttingen Hoarseness Diagram)., Results: After laser surgery, the patients' respiratory function was significantly increased and was sufficient for all activities of daily living. The body plethysmographic measure of airway resistance had superior descriptive power and correlated significantly with the clinical degree of dyspnea (scale 0 to 3). Pretreatment and posttreatment impairment of voice quality was objectively documented with the Göttingen Hoarseness Diagram; the phonatory results measured with it correlated significantly with the subjective clinical evaluation of hoarseness. Aphonia did not occur., Conclusions: A bilateral approach for laser microsurgical posterior cordectomy combines excellent airway improvement and satisfactory voice preservation. In bilateral vocal fold paralysis, pretreatment and posttreatment clinical data should be evaluated by objective measures.

Background: Recurrent laryngeal nerve monitoring (RLNM) has been suspected to reduce postoperative RLN paralysis (RLNP). However, functional outcome of RLNM in comparison with no nerve identification and visual nerve identification only has not been analyzed., Methods: Analysis of 16,448 consecutive multi-institutional operations resulted in 29,998 nerves at risk. Three groups of different RLN treatment were compared: group 1, no RLN identification; group 2, visual RLN identification; and group 3, visual RLN identification and electromyographic monitoring. RLNM was performed with a bipolar needle electrode that was placed through the cricothyroid ligament into the vocal muscle., Results: Risk factors for permanent RLNP were recurrent benign and malignant goiter (odds ratios, [ORs]), 4.7, and 6.7, respectively), primary surgery in thyroid malignancy (OR, 2.0), lobectomy (OR, 1.8), no nerve identification (OR, 1.4), low or medium volume hospital (OR, 1.3), and low volume surgeons (OR, 1.2)., Conclusions: Based on these data, visual nerve identification was identified to be the gold standard of RLN treatment in thyroid surgery. RLNM is a promising tool for nerve identification and protection in extended thyroid resection procedures. However, because of the overall low frequency of RLNP, no statistical difference compared with visual nerve identification only was reached in the setting of this study.

Intraoperative neuromonitoring (IONM) has yielded an increasing effect on thyroid surgery. During IONM, the recurrent laryngeal nerve is stimulated electrically and an acoustically transformed electromyographic signal is derived via either a needle electrode placed in the vocalis muscle or an electrode adjusted to the intubation tube. The IONM is used for identifying and predicting the function of the recurrent laryngeal nerve. Especially under difficult anatomic conditions, IONM has proven a valuable tool for identification of recurrent laryngeal nerves. This can lead to decreased occurrence of nerve palsy rates, as shown in numerous studies. The reliability of the IONM signal (defined as the correlation between intraoperative signal interpretation and postoperative vocal cord function) is reflected by a specificity as high as 98.2%, as shown by German multicenter studies. Thus, normal vocal cord function could be demonstrated postoperatively in over 98.2% of patients with intraoperatively unchanged neuromonitoring signals. If the neuromonitoring signal changed during operation, 39% of the patients suffered from transient vocal cord immobility and 12% had permanent loss of vocal cord function.

Since the phoniatrician H. Bauer described the first case of recurrent laryngeal nerve palsy most likely caused by intubation some 45 years ago, several case reports have been published. However, systematic analyses regarding the frequency of recurrent laryngeal nerve palsies due to intubation are scarce, and none of them has used the proper methods to demonstrate clearly that such a mechanism exists. Currently available data justify the assumption that not every recurrent laryngeal nerve palsy following thyroid surgery is due to the operation itself and that the damage caused by intubation, however, may only account for a minority of these cases. The differential diagnosis of postoperative recurrent laryngeal nerve palsy requires the use of specific tools which go beyond simple laryngoscopy and include stroboscopy as well as intra- and extralaryngeal electromyography. A partial palsy of recurrent laryngeal nerve due to intubation would be associated with severe dysphonia or aphonia, not with dyspnea because of the typical intermediate position of the paralyzed vocal folds with a normal electromyographic function of the cricothyroid muscle. The use of these methods to identify the nature of postoperative recurrent laryngeal nerve palsy is recommended in cases of regular intraoperative neuromonitoring but postoperatively impaired function of the vocal cords.

The need for an objective assessment of voice quality can be seen in the increasing use of acoustic analysis methods for clinical diagnosis and research. The hoarseness diagram allows clinicians to objectively describe even highly disturbed or aphonic votes. Its application possibilities are illustrated in three case studies in which changes in voice quality were monitored during voice rehabilitation. The distributions of voice groups that were defined on the basis of specific pathophysiological phonation conditions were then compared for their acoustic differences. The groups comprised various phonation conditions after the resection of laryngeal tumors and different types of laryngeal paralyses. Interpretation of the results suggests a direct correspondence of the hoarseness diagram coordinates and the irregularity of vibration on the one side and the degree of glottal closure on the other. This illustrates the potential usefulness of the hoarseness diagram in a clinical context.

The phoniatric-logopedic therapeutical possibilities and results of the two most frequent causes of paralysis following a Strumectomy are presented here. The major aspect of this treatment is the application of electric therapy. Its correct usage will be explained. This "conservative" therapy should precede every operative measure and should follow again once the wound has healed. A new post-operative phoniatric therapy method following Glottis widening surgery will also be described. This therapy is based upon the functioning of the Ventricularis muscle, which operates independent of the Recurrens nerve. Furthermore, this therapy functions independent of the operation methods and leaves the natural vocal cord phonation intact, despite vocal cord paralysis.