Voice tremor: what we know and what we do not know

Intergenerational choral singing to improve communication outcomes in Parkinson's disease: Development of a theoretical framework and an integrated measurement tool

Purpose: This study presented an initial step towards developing the evidence base for intergenerational choral singing as a communication-focussed rehabilitative approach for Parkinson's disease (PD).Method: A theoretical framework was established to conceptualise the rehabilitative effect of intergenerational choral singing on four domains of communication impairments - motor drive, timing mechanism, sensorimotor integration, higher-level cognitive and affective functions - as well as activity/participation, and quality of life. A computer-assisted multidimensional acoustic analysis was developed to objectively assess the targeted domains of communication impairments. Voice Handicap Index and the World Health Organization's Quality of Life assessment-abbreviated version were used to obtain patient-reported outcomes at the activity/participation and quality of life levels. As a proof of concept, a single subject with PD was recruited to participate in 9 weekly 1-h intergenerational choir rehearsals. The subject was assessed before, 1 week post, and 8 weeks post-choir.Result: Notable trends of improvement were observed in multiple domains of communication impairments at 1 week post-choir. Some improvements were maintained at 8 weeks post-choir. Patient-reported outcomes exhibited limited pre-post changes.Conclusion: This study provided the theoretical groundwork and an empirical measurement tool for future validation of intergenerational choral singing as a novel rehabilitation for PD.

An Unusual Etiology of Vocal Tremor in a Professional Singer

Vocal tremor is a neurologic disorder with myriad etiologies (eg, Parkinson disease, medications, or essential tremor). Vocal tremor can limit intelligibility and social interaction and can result in isolation in nonprofessional voice users. In a professional singer whose entire career is based on voice quality, onset of a vocal tremor is devastating. We report a case of sudden-onset vocal tremor that impeded a young professional singer's ability to perform and record her album. The etiology was determined to be a medication side effect of lamotrigine; a reaction that has not been previously reported. Diagnosis was based on perceptual assessment of the vocal tremor, laryngeal examination, and the singer's proximate history of lamotrigine dose adjustment. Two months after decreasing her dose, all symptoms resolved and the singer returned to her tour and performance schedule. To our knowledge, this is the first report of isolated vocal tremor as a side effect of lamotrigine and demonstrates that the voice may be more sensitive to this class of medication than previously described. It is incumbent on the vocal professional to inquire about and understand that new medication or dose changes may impact their voice.

Vocal tract characteristics in Parkinson's disease

PURPOSE OF REVIEW

Voice tremor is strongly linked to the Parkinson's disease speech-voice symptom complex. Little is known about the underlying anatomic source(s) of voice tremor when it occurs. We review recent literature addressing this issue. Additionally we report findings from a study we conducted employing rating of vocal tract structures viewed using nasolaryngoscopy during vocal and nonspeech tasks.

RECENT FINDINGS

In Parkinson's disease, using laryngeal electromyography, tremor has not been identified in muscles in the vocal folds even when perceived auditorily. Preliminary findings using nasolaryngoscopy suggest that Parkinson's disease voice tremor is not associated with the vocal folds and may involve the palate, the global larynx, and the arytenoids. Tremor in the vertical larynx on /a/, and tremor in the arytenoid cartilages on /s/ differentiated patients with Parkinson's disease from neurologically healthy controls. Visual reliable detection of tremor when it is absent or borderline present, is challenging.

SUMMARY

Parkinson's disease voice tremor is likely to be related to oscillatory movement in structures across the vocal tract rather than just the vocal folds. To progress clinical practice, more refined tools for the visual rating of tremor would be beneficial. How far voice tremor represents a functionally significant factor for speakers would also add to the literature.

Dystonia and Tremor: The Clinical Syndromes with Isolated Tremor

BACKGROUND

Dystonia and tremor share many commonalities. Isolated tremor is part of the phenomenological spectrum of isolated dystonia and of essential tremor. The occurrence of subtle features of dystonia may allow one to differentiate dystonic tremor from essential tremor. Diagnostic uncertainty is enhanced when no features of dystonia are found in patients with a tremor syndrome, raising the question whether the observed phenomenology is an incomplete form of dystonia.

METHODS

Known forms of syndromes with isolated tremor are reviewed. Diagnostic uncertainties between tremor and dystonia are put into perspective.

RESULTS

The following isolated tremor syndromes are reviewed: essential tremor, head tremor, voice tremor, jaw tremor, and upper-limb tremor. Their varied phenomenology is analyzed and appraised in the light of a possible relationship with dystonia.

DISCUSSION

Clinicians making a diagnosis of isolated tremor should remain vigilant for the detection of features of dystonia. This is in keeping with the recent view that isolated tremor may be an incomplete phenomenology of dystonia.

Deep brain stimulation for vocal tremor: a comprehensive, multidisciplinary methodology

Tremulous voice is a characteristic feature of a multitude of movement disorders, but when it occurs in individuals diagnosed with essential tremor, it is referred to as essential vocal tremor (EVT). For individuals with EVT, their tremulous voice is associated with significant social embarrassment and in severe cases may result in the discontinuation of employment and hobbies. Management of EVT is extremely difficult, and current behavioral and medical interventions for vocal tremor result in suboptimal outcomes. Deep brain stimulation (DBS) has been proposed as a potential therapeutic avenue for EVT, but few studies can be identified that have systematically examined improvements in EVT following DBS. The authors describe a case of awake bilateral DBS targeting the ventral intermediate nucleus for a patient suffering from severe voice and arm tremor. They also present their comprehensive, multidisciplinary methodology for definitive treatment of EVT via DBS. To the authors’ knowledge, this is the first time comprehensive intraoperative voice evaluation has been used to guide microelectrode/stimulator placement, as well as the first time that standard pre- and post-DBS assessments have been conducted, demonstrating the efficacy of this tailored DBS approach.

Uso de substâncias psicoativas, alterações vocais e qualidade de vida em usuários de drogas lícitas e ilícitas

OBJETIVOS:investigar a qualidade de vida e voz, além das principais alterações perceptivo-auditivas e as medidas acústicas jitter, shimmer e Glottal Noise Excitation em usuários de substâncias psicoativas lícitas e/ou ilícitas que buscaram um centro de tratamento para dependência química.MÉTODOS:estudo transversal. Os participantes responderam aos questionários de Mensuração de Qualidade de Vida em Voze World Health Organization Quality of Life Instrument-Bref. Além disso foi realizado, um registro vocal da vogal /a/ e de uma contagem de números de 1 a 20. Os registros vocais foram avaliados por meio da escala GRBAS-I (G - grau global da disfonia, R - rugosidade, B - soprosidade, A - astenia, S - tensão) e a análise acústica (jitter, shimmer, Glottal noise excitation) pelo software VoxMetria.RESULTADOS:avaliaram-se 29 protocolos e registros de voz; na amostra, 19 (65,5%) eram homens; a idade média da amostra foi de 37,8 anos. Os escores de ambos os questionários não apresentaram diferenças entre os usuários de drogas lícitas e os de drogas ilícitas. Na análise perceptiva por meio da GRBAS-I, eles mostraram predominância de alterações discretas e moderadas nos itens grau geral da disfonia, rugosidade e instabilidade para usuárias de drogas ilícitas. A medida acústica jitter e o shimmerestavam alterados para homens e mulheres, e o desvio padrão da frequência fundamental também estava alterado.CONCLUSÃO:alterações de qualidade de vida e voz foram identificadas em ambos os usuários. A maioria dos usuários apresentou alterações nas medidas de jittere shimmer.Usuários de drogas ilícitas apresentaram mais alterações de Glottal Noise Excitation e desvio padrão da frequência fundamental.

Speech, voice and language in Parkinson’s disease: changes and interventions

SUMMARY This article covers recent developments in the understanding of communication changes in idiopathic Parkinson’s disease and selected issues in intervention. By contrast to earlier narrow considerations of voice and speech, the effects on communication of cognitive–linguistic and prosody perception and production are also highlighted. Decline can occur from the earliest stages, even when listeners perceive no frank changes. Communication may be relatively trouble-free in one-to-one quiet clinical situations but declines in multi-talker, dual/competing task situations. Assessment should reflect this to gain more accurate insights into daily living performance. Currently, therapies focusing on attention-to-effort in voice production and on monitoring the sense of effort and loudness production appear to be most successful. Medical and surgical treatments have little effect on intelligibility and communication and may even exacerbate the situation.