Prognostic Value of Laryngeal Electromyography in Vocal Fold Paralysis

Objective To analyze the value of electromyography in predicting recovery from acute neurogenic vocal fold paralysis. Study Design Prospective case series. Setting University-based hospital of otorhinolaryngology–head and neck surgery. Patients Ninety-eight patients (56 women, with a mean age of 62.2 years; 42 men, with a mean age of 39.8 years) with 111 paralyzed vocal folds. The causes were varied, with thyroid surgery (53 cases) and idiopathic palsy (18 cases) being the predominant factors. Intervention Prognostication was based on electromyography performed no earlier than 14 days after onset of palsy. Findings were classified as neurapraxy, axonotmesis, and neurotmesis. Prognosis is inherent in this classification, since neurapraxy is presumed to resolve completely within 8 to 12 weeks, whereas axonotmesis is most likely to be followed by impaired vocal fold mobility. Main Outcome Measures Vocal fold mobility after 6 months. Results In 102 vocal folds, some palsy of various degree persisted after 6 months. Free mobility of the paralyzed vocal fold was restored in 9 cases. By means of laryngeal electromyography, defective recovery, defined as absence of completely free vocal fold mobility, was predicted correctly in 94.4% of cases (68/72). For complete recovery, prognosis was accurate in only 12.8% of cases (5/39). Conclusions The detection of neural degeneration by laryngeal electromyography allows the prediction of poor functional outcome with sufficient reliability in an early phase of the disease process. Conversely, the absence of signs of degeneration does not imply that complete recovery is to be expected.