Behavioral Management of Respiratory/Phonatory Dysfunction for Dysarthria Associated With Neurodegenerative Disease: A Systematic Review

American Journal of Speech-Language Pathology

Perry, S. E., Troche, M., et al. (2024).

American Journal of Speech-Language Pathology, 33(2), 1069-1097.

<div>This systematic review investigates therapeutic behavioral interventions (e.g., behavioral and device-driven interventions, compensatory strategies, stimulability for use of speech-related cues) on respiratory or phonatory dysfunction in adults with dysarthria related to an underlying neurodegenerative condition.</div>

No funding received

From database inception to November 2, 2020

<div>Published, peer-reviewed English-language intervention studies of any design. Excludes books, review articles, conference abstracts, correspondence articles, case studies, and case series.</div>

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<div>Strong evidence supported the use of the Lee Silverman Voice Treatment (LSVT) LOUD program for individuals with dysarthria secondary to Parkinson's disease (PD). Specific findings included:</div> <ul> <li><span style="color: #333333;">Twenty-eight studies found increased vocal intensity ranging from 2.3 to 31.0 dB depending on the elicitation task following LSVT LOUD treatment. </span></li> <li><span style="color: #333333;">Some studies demonstrated maintenance of these improvements at follow-ups ranging from 1 month to 24 months post-treatment. </span></li> <li><span style="color: #333333;">Two studies showed that in-person and remote provision of LSVT LOUD resulted in comparable outcomes. </span></li> <li><span style="color: #333333;">Two other studies reported similar outcomes for both intensive treatment (i.e., four times per week for 4 weeks) and less intensive treatment schedules (i.e., two times per week for 4-8 weeks). </span></li> <li><span style="color: #333333;">One study comparing LSVT LOUD to LSVT ARTIC found larger vocal intensity outcomes after LSVT LOUD intervention. </span></li> <li><span style="color: #333333;">LSVT had inconsistent effects on fundamental frequency, vocal pitch range, amplitude range, and lexical tone. </span></li> <li><span style="color: #333333;">Participants had positive outcomes for some perceptual variables (i.e., breathiness, voice scratchiness, strain, phonation, respiration, vowel representation, vocal quality) and mixed findings for other perceptual variables (i.e., hoarseness, articulatory precision, prosody, roughness). </span></li> <li><span style="color: #333333;">LSVT LOUD also demonstrated mixed effects for respiratory and laryngeal outcomes (e.g., subglottal air pressure, forced vital capacity, utterance duration). </span></li> <li><span style="color: #333333;">Studies investigating patient-reported outcomes or quality of life reported positive to mixed outcomes. </span></li> </ul> <div><span style="color: #333333;">The authors note limitations of this review including the type of quality scale used to assess the evidence, the lack of statistical power of effect estimates, and the lack of individuals with non-degenerative disorders. Additional research is warranted.</span></div>

<div>Other than LSVT, no other voice treatment approach "demonstrated more than limited evidence" (p. 1088) for managing respiratory or phonatory dysfunction in adults with dysarthria related to underlying neurodegenerative conditions. The authors note limitations of this review including the type of quality scale used to assess the evidence, the lack of statistical power of effect estimates, and the lack of individuals with non-degenerative disorders. Additional research is warranted.</div>