Differential diagnosis of muscle tension dysphonia and spasmodic dysphonia.
ABSTRACT Muscle tension dysphonia (MTD) can mimic the voice features of adductor spasmodic dysphonia (ADSD) leading to diagnostic confusion. Researchers have begun to compare characteristics of MTD and ADSD to determine whether there are markers which reliably distinguish the two disorders and lead to improved differential diagnosis.
Differences between MTD and ADSD have been identified during fiberoptic laryngoscopy, phonatory airflow measurement, acoustic analysis, and variable sign expression based upon phonatory task. In general, evidence of task-dependent sign expression and intraword phonatory breaks should raise suspicion of ADSD over MTD. However, on the basis of conventional standards of diagnostic precision, no single diagnostic test currently exists that reliably distinguishes the two disorders.
Although perceptual voice evaluation remains the standard for differential diagnosis of ADSD and MTD, knowledge of factors that influence the severity of sign expression in ADSD is important to differential diagnosis. During clinical assessment, voice clinicians who use generic stimulus materials that do not control for specific phonetic environments or voice tasks may miss critical phenomenological features of ADSD.
- SourceAvailable from: Tim LynchMovement Disorders 03/2012; 27(3):346-8. · 5.63 Impact Factor
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ABSTRACT: Abstract The occurrence of intermittent aphonia, perceived as sudden interruptions of voicing in connected speech, often reflects high stiffness of the vocal fold mucosa as part of a voice disorder. This retrospective study aimed to investigate the overarching hypothesis that the aphonic instances in voices with intermittent aphonia are not totally randomly appearing, but related to syllable stress and phonetic context. Recordings of 31 dysphonic patients with intermittent aphonia reading a standard text were analyzed perceptually. All vowels of the text were labelled and categorized with regard to syllable stress and character of the phoneme preceding the vowel. The occurrence of aphonic instances within each syllable category was analyzed. Four different hypotheses were formulated and analyzed by the non-parametric Wilcoxon's signed-ranks test. The results showed a significantly higher occurrence of aphonic instances in unstressed syllables as opposed to stressed, in vowels following an unvoiced phoneme as opposed to a voiced, and in vowels following two or more unvoiced phonemes as opposed to one unvoiced phoneme. No significant difference was found between vowels following aspirated stops [p], [t], [k] as opposed to unaspirated stops [b], [d], [g]. The findings support the theory that both physiological and functional aspects may contribute to the phenomenon of intermittent aphonia.Clinical Linguistics & Phonetics 03/2014; · 0.78 Impact Factor
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ABSTRACT: To determine the short-term disability (STD) and lost work productivity related to laryngeal disorders. A retrospective analysis of a national database of work absence and STD claims was performed. Patients with 12 months of follow-up who had an STD claim specifically linked to a dysphonia diagnosis based on ICD-9 codes were identified during the period of January 1, 2004, to December 31, 2008. Patient age, sex, and diagnosis and the total number of work days absent were determined. Using the mean national hourly wage, productivity losses in terms of lost wages were calculated. Of the 18,466 unique patients with an STD claim, 386 (2.1%) had an STD claim due to a laryngeal disorder. The mean age was 45.9 years (standard deviation, 9.6) with 53.2% male. The mean number of work days absent was 39.2 days (95% confidence interval: 31.9-46.5). Total STD payments in 2008 dollars were $647,269.30 with a mean per person in 12 months of $3,406.68. Total and mean lost wages in 12 months were $843,198.72 and $4,437.89, respectively. Patients with laryngeal cancer had the most days absent and highest total STD payment. Laryngeal disorders lead to work-related disability with STD and productivity losses and represent a significant societal burden. Managing work limitations from laryngeal disorders is an important public health goal.The Laryngoscope 05/2012; 122(7):1589-94. · 1.98 Impact Factor