Quantification of sound instability in embouchure tremor based on the time-varying fundamental frequency

Is essential tremor a family of diseases or a syndrome? A family of diseases

It is now well-established that essential tremor (ET) can manifest with different clinical presentations and progressions (i.e., upper limb tremor, head tremor, voice tremor, lower limb tremor, task- or position-specific tremor, or a combination of those). Common traits and overlaps are identifiable across these different subtypes of ET, including a slow rate of progression, a response to alcohol and a positive family history. At the same time, each of these manifestations are associated with specific demographic, clinical and treatment-response characteristics suggesting a family of diseases rather than a spectrum of a syndrome. Here we summarize the most important clinical, demographic, neuropathological and imagingfeatures of ET and of its subtypes to support ET as a family of identifiable conditions. This classification has relevance for counseling of patients with regard to disease progression and treatment response, as well as for the design of therapeutic clinical trials.

Musculoskeletal and psychological assessments used in quantitatively based studies about musicians' health in brass players: A systematic literature review

OBJECTIVE

Brass players are exposed to high musculoskeletal strains during their instrumental play. Various assessments can be used to measure these strains, whereby a targeted therapy can also be supported. The aim of this study was to review literature concerning assessments used in quantitatively based studies about the analysis of musculoskeletal loads of brass players.

DATA SOURCES

The Cochrane Library, PubMed, CINAHL, PEDro as well as the journal "Medical Problems of Performing Artists" were searched for relevant studies.

STUDY SELECTION

Two reviewers independently applied the inclusion and exclusion criteria to select potential studies. A third reviewer was involved in the case of discrepancies.

DATA EXTRACTION

Two reviewers independently extracted the data.

DATA SYNTHESIS

A total of 73 studies conducted between 2004 and 2019 were included. Within a total of 30 studies, 18 assessments could be found that collect 2-dimensional or 3-dimensional kinematic data using video- or image-based analysis of posture, sonographic, optoelectronic and various electromagnetic systems. In 7 studies kinetic data were measured by force-transducers, pressure platforms, stabilizer and dynamometer. Fifteen studies used clinical examinations and additional assessments to screen individual body regions and 9 studies derived electromyography measurements from a total of 25 muscles. Thirty-one partially validated questionnaires were used to record musculoskeletal pain of brass players.

CONCLUSIONS

A variety of assessments can be used to optimize analysis and treatment procedures in research and clinical work. Future studies should both examine quality criteria of the various assessment methods and validate clinical examinations and questionnaires.

Acoustic, perceptual and clinical correlates of speech and voice in isolated dystonia: Preliminary findings

BACKGROUND

Hyperkinetic dysarthria is often present in isolated dystonia (ID) and is still understudied. Four main clusters of deviant speech dimensions in dystonia hyperkinetic dysarthria were initially provided: articulatory inaccuracy, phonatory stenosis, prosodic excess and prosodic insufficiency.

AIM

The aim of our exploratory study was to provide preliminary data on both perceptual and acoustic analyses in relation to three out of these four main clusters.

METHODS & PROCEDURES

Eleven patients with ID and 11 healthy controls (HC) participated in this study. Clinical/perceptual assessments and acoustic analyses of speech recordings were performed, the latter allowing for the analysis of parameters referring to aerophonatory control, voice quality, prosodic features and speech intelligibility estimated by nine listeners. Between-group statistical comparisons were performed (Wilcoxon tests, p < 0.05). Single-case differences between each patient and the control group were also carried out (effect size index and t < 0.05).

OUTCOMES & RESULTS

Between-group comparisons confirmed the presence of a 'phonatory stenosis'; in addition, deficit in aerophonatory control and hypophonia was also displayed. 'Prosodic insufficiency' was confirmed, but not at the individual level. 'Prosodic excess' manifested only in patients with marked and severe dysarthria. Correlations between altered maximum phonation time, loudness variation, speech and articulatory rates on the one hand, and several clinical speech assessments on the other hand, were also found.

CONCLUSIONS & IMPLICATIONS

From these findings, altogether, perceptual characteristics of hyperkinetic dysarthria, as suggested by Darley et al., were quantified by the acoustic parameters we measured. As regards to our data obtained in a small participant sample, we would suggest that Darley et al.'s clusters of excess and insufficiency prosody should be questioned in future studies involving larger numbers of dystonic patients. Our study provides novel and preliminary results that demonstrate the relevance of using quantitative measures to further characterise speech/voice deficits in patients with ID.

Dystonia in Performing Artists: Beyond Focal Hand Dystonia

Overuse of specific muscles in perfecting movements in performing arts makes an artist prone to many medical conditions. Musicians' hand dystonia is focal task-specific dystonia (FTSD) of hand among musicians that has been extensively studied. However, embouchure, lower limbs, and laryngeal muscles can also be affected among musicians. Embouchure dystonia (ED) refers to dystonia of the perioral and facial muscles that occurs in musicians while playing embouchure instruments. It is essential to identify ED since the dystonia might become persistent and non-task-specific if the musician continues to play the instrument. Task-specific dystonia of lower limbs among musicians has been exclusively reported among drummers. The diagnosis rests on electromyogram (EMG) of the involved muscles during the task. Singer's dystonia (SD) refers to task-specific laryngeal dystonia that occurs only while singing. The diagnosis of SD is based on laryngeal EMG and spectrographic analysis. Cortical hyperexcitability, loss of inhibition, and aberrant plasticity are central to the pathogenesis in both ED and musicians' hand dystonia. The pathophysiological studies in SD are limited. This review aims to discuss the lesser known dystonias among performing artists - ED, FTSD of lower limb, and SD.

Quantitative, clinically relevant acoustic measurements of focal embouchure dystonia

BACKGROUND

Focal embouchure dystonia impairs orofacial motor control in wind musicians and causes professional disability. A paucity of quantitative measures or rating scales impedes the objective assessment of treatment efficacy.

OBJECTIVES

We quantified specific features of focal embouchure dystonia using acoustic measures and developed a metric to assess severity across multiple domains of symptomatic impairment.

METHODS

We recruited 9 brass musicians with and 6 without embouchure dystonia. The following 4 domains of symptomatic dysfunction in focal embouchure dystonia were identified: pitch inaccuracy, sound instability and tremor, sound breaks, and timing variability. Musicians performed sustained tones and sequences, and then acoustic variables within each domain were quantified. A composite brass acoustic severity score composed of these variables was validated against clinical global impressions of severity.

RESULTS

Musicians with dystonia performed worse in acoustic domains of pitch inaccuracy (median: dystonia = 100%, control = 62%), instability (median shimmer: dystonia = 3%, control = 2%), and breaks (median: dystonia = 0.34%, control = 0.05%). Tremor in embouchure dystonia was 5 to 8 Hz, intermittent, and variable in amplitude. Rhythmic variability did not differ between groups. Participants with embouchure dystonia had different patterns of impairment across variables. Composite severity scores strongly predicted clinical global impression of severity (R2  = 0.95).

CONCLUSIONS

Acoustic variables distinguish musicians with embouchure dystonia from controls and reflect different types of symptomatic impairments. Our composite acoustic severity score predicts severity of clinical global impression for musicians with different patterns of symptomatic impairment and may provide a foundation for developing a clinical rating scale. © 2018 International Parkinson and Movement Disorder Society.