Prognostic Indicators of Unilateral Vocal Fold Paralysis

Abstract

To determine the possible prognostic indicators of unilateral vocal fold paralysis (UVFP) and survey the timing and values of preset laryngeal electromyography (LEMG) rules for UVFP. Design: Cohort study with retrospective data analysis. Setting: Voice clinic of a tertiary medical center. Patients: Complete data for 45 patients diagnosed with idiopathic or iatrogenic UVFP. The LEMG was performed between 3 weeks and 6 months from the onset of symptoms. Main Outcome Measure: At least 6 months after symptom onset and 3 months after LEMG. Results: Thirteen subjects showed resolved vocal fold motion (29%), and 32 had persistent vocal fold paralysis (71%). According to the LEMG decision rules proposed by Munin et al in 2003, the predictive values for positive results, negative results, sensitivity, specificity, and accuracy of LEMG were 78.9%, 71.4%, 93.8%, 38.5%, and 77.8%, respectively. We found the false-positive rate to be as high as 50% if LEMG was performed less than 2 months after symptom onset, and only 7.7% if LEMG was performed at least 2 months after symptom onset. After excluding 14 LEMG data recorded at less than 2 months, the predictive values for positive results, negative results, sensitivity, specificity, and accuracy of LEMG were 92.3%, 60%, 92.3%, 60.0%, and 87.1%, respectively. The predictive values of positive results and accuracy significantly improved without compromising sensitivity. Conclusion: This study confirms that LEMG is a clinically useful tool that can offer prognostic information for UVFP especially if it is done at least 2 months after symptom onset.

Electromyographic laryngeal synkinesis alters prognosis in vocal fold paralysis

“…The reported prognostic value of diagnostic LEMG is variable in the literature, but utilization of discreet electromyographic criteria improves the utility in assessing prognosis for recovery of VF motion. 1,2 Even so, the negative predictive value of this paradigm was previously reported as 66.7% to 78.9%. 1,2 In this setting, false-negative LEMG studies were present in patients who have objective LEMG findings that are favorable for recovery, such as good motor unit recruitment and absence of spontaneous activity, but did not recover purposeful VF motion.…”

Laryngeal Electromyography-Guided Hyaluronic Acid Vocal Fold Injection for Unilateral Vocal Fold Paralysis

“…According to our previous retrospective study, the accuracy of LEMG in predicting the outcome of UVFP is 87.1%. 6 However, the hyaluronic acid injection cannot guarantee a permanent effect. If a patient's symptoms recur after the injection, a poor prognosis will be clinical evidence that the patient should undergo permanent open laryngeal framework surgery.…”

“…Since it was developed in 1944, LEMG has been widely used for guiding botulinum toxin injection for spasmodic dysphonia and predicting the prognosis of UVFP. 6,7,24 In addition, an electromyographic machine is not a common piece of equipment in an otolaryngological department, which may also be a drawback. However, a voice surgeon could cooperate with neurologist to compensate for this inconvenience.…”

“…All patients received LEMG for evaluation of the neuromuscular function of immobile VF and guidance of hyaluronic acid injection, which was described in detail in our previous publications. 6,8,9 Briefly, after patients were placed in a supine position without using any anesthesia, the first author (C.-C.W.) inserted a 26-gauge monopolar injectable needle electrode (Bo-ject Disposable Needle Electrode, AlpineBiomed ApS) at the level of the cricothyroid membrane on the normal side of the larynx approximately 0.5 cm from the midline.…”

Is Unilateral Vocal Fold Paralysis a Rare Complication of Spinal Anesthesia? A Case Report

“…This may occur alone or in combination with an injury to the superior laryngeal nerve (SLN). Laryngeal electromyography (EMG) is a clinically useful tool in the management of laryngeal nerve injuries; it has prognostic value if it is used at least two months after the onset of symptoms [1]. Most of the nerve injuries that lead to VFP arise from three main causes: mechanical trauma from surgery of the thyroid, head, and neck; malignant growth causing pressure on the vagus nerve or RLN; or inflammatory processes, usually viral infections [2][3][4].…”