ABSTRACT
Laryngeal electromyography (LEMG) is a valuable adjunct in clinical management of patients with voice disorders. LEMG is valuable in differentiating vocal fold paresis/paralysis from cricoarytenoid joint fixation. Our data indicate that visual assessment alone is inadequate to diagnose neuromuscular dysfunction in the larynx and that diagnoses based on vocal dynamics assessment and strobovideolaryngoscopy are wrong in nearly one-third of cases, based on LEMG results. LEMG has also proven valuable in diagnosing neuromuscular dysfunction in some dysphonic patients with no obvious vocal fold movement abnormalities observed during strobovideolaryngoscopy. Review of 751 patients suggests that there is a correlation between the severity of paresis and treatment required to achieve satisfactory outcomes; that is, LEMG allows us to predict whether patients will probably require therapy alone or therapy combined with surgery. Additional evidence-based research should be encouraged to evaluate efficacy further.
Subject(s)
Electromyography/methods , Larynx/physiopathology , Vocal Cord Paralysis/diagnosis , Vocal Cord Paralysis/physiopathology , Voice Disorders/diagnosis , Voice Disorders/physiopathology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Diagnosis, Differential , Female , Humans , Laryngoscopy/methods , Male , Middle Aged , Motion , Severity of Illness Index , Stroboscopy/methods , Treatment Outcome , Video Recording/methods , Vocal Cord Paralysis/therapy , Vocal Cords/physiopathology , Voice Disorders/therapy , Young AdultABSTRACT
Quantification of perceptual voice characteristics allows the assessment of voice changes. Acoustic measures of jitter, shimmer, and noise-to-harmonic ratio (NHR) are often unreliable. Measures of cepstral peak prominence (CPP) may be more reliable predictors of dysphonia. Trained listeners analyzed voice samples from 281 patients. The NHR, amplitude perturbation quotient, smoothed pitch perturbation quotient, percent jitter, and CPP were obtained from sustained vowel phonation, and the CPP was obtained from running speech. For the first time, normal and abnormal values of CPP were defined, and they were compared with other acoustic measures used to predict dysphonia. The CPP for running speech is a good predictor and a more reliable measure of dysphonia than are acoustic measures of jitter, shimmer, and NHR.
Subject(s)
Speech Acoustics , Voice Disorders/diagnosis , Aged , Aged, 80 and over , Child , Female , Humans , Male , Middle Aged , Observer Variation , ROC Curve , Reference Values , Sensitivity and Specificity , Severity of Illness Index , Time Factors , Voice Disorders/epidemiology , Voice QualityABSTRACT
Vocal tremor has been a challenging problem for patients and their physicians. In some cases, it has been possible to lesson the symptom's tremor through medications and/or voice therapy. However, in most cases no good treatment has been available. Chronic stimulation of the thalamus has been successful in controlling tremors of the upper limb and other portions of the body. Our preliminary experience suggests that it may also be helpful in controlling vocal tremor.
