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Published on: February 21, 2011
Electroglottographic tracking of phonatory response to Botox
K V Fisher1, R C Scherer, P R Swank
1Northwestern University, Department of Communication Sciences and Disorders, Evanston, Illinois 60208, USA.
Journal of Voice : Official Journal of the Voice Foundation
|August 12, 1999
Summary
Botox injections for adductor spasmodic dysphonia (ADSD) can cause temporary voice issues. Electroglottography revealed varied vocal fold responses and recovery times in patients, highlighting individual differences in treatment outcomes.
Area of Science:
- Laryngology
- Speech-Language Pathology
- Neurology
Background:
- Adductor spasmodic dysphonia (ADSD) is often treated with botulinum toxin (Botox) injections into the thyroarytenoid muscle.
- This intervention aims to improve glottal competence and laryngeal adduction.
- Treatment outcomes can include subjective reports of hypofunctional voice, such as breathiness or aphonia, and objective findings like glottal gaps or aspiration.
Purpose of the Study:
- To objectively examine changes in glottal competence over time using electroglottography (EGG) following Botox injections in patients with ADSD.
- To investigate the temporal dynamics of laryngeal adduction and vocal fold contact post-injection.
- To explore inter-patient variability in hypofunctional responses and their relationship to symptom severity.
Main Methods:
- Five patients diagnosed with ADSD underwent Botox injections.
- Electroglottography (EGG) was employed to measure vocal fold contact patterns during phonation over an 8-week period post-injection.
- Hierarchical linear modeling was utilized to analyze changes in glottal competence and compare individual response trajectories.
Main Results:
- Three participants exhibited significant vocal fold hypoadduction post-injection, with a subsequent reversal towards pre-injection levels within 8 weeks.
- Two participants showed stable or increasing vocal fold contact, indicating a lack of hypofunction or a different response pattern.
- Observed variations in EGG measures align with previously reported subjective differences in hypofunctional recovery and ADSD symptom resolution.
Conclusions:
- Botox injections for ADSD can lead to measurable, albeit variable, changes in glottal competence.
- Individual responses to Botox vary, with some patients experiencing transient hypoadduction and others showing different vocal fold contact patterns.
- The study underscores the complex relationship between post-injection vocal fold function, hypofunction resolution, and the return of ADSD symptoms, supporting the need for individualized treatment monitoring.
