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Ultrasound-guided Botulinum Toxin-A Injections: A Method of Treating Sialorrhea
Published on: November 9, 2016
Botulinum toxin injection and airflow stability in spasmodic dysphonia
Giovanna Cantarella1, Alessandra Berlusconi, Barbara Maraschi
1Department of Otolaryngology, Fondazione Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, IRCCS, Pad. Alfieri, Via Commenda 10, 20122 Milan, Italy. giovanna.cantarella@policlinico.mi.it
Summary
Botulinum toxin (BT) injection improved phonatory airflow stability in adductor spasmodic dysphonia (SD) patients by reducing airflow variation. This suggests BT may alter laryngeal neural activity, not just muscle function.
Area of Science:
- Laryngology
- Neurology
- Speech Science
Background:
- Adductor spasmodic dysphonia (SD) is characterized by involuntary vocal fold closure, leading to voice instability.
- Phonatory airflow instability is a key but often unquantified feature of SD.
Purpose of the Study:
- To investigate the impact of botulinum toxin (BT) on phonatory airflow stability in adductor SD.
- To assess mean phonatory oral airflow and its coefficient of variation (CV) before and after BT injection.
Main Methods:
- Evaluated 24 SD patients and 23 controls for mean airflow and CV during sustained phonation.
- Assessed 15 SD patients within 3 weeks post-BT injection for changes in airflow and CV.
Main Results:
- BT injection increased airflow in SD patients, though values remained comparable to controls.
- Airflow CV was significantly higher in SD patients than controls.
- A significant decrease in airflow CV was observed post-BT in patients with perceived voice improvement, irrespective of airflow increase.
Conclusions:
- SD patients exhibit significantly unstable phonatory airflow, measurable by CV.
- Reduced airflow CV post-BT injection in SD patients may indicate altered laryngeal motoneuronal activity.
- Airflow CV is a valid metric for evaluating BT treatment outcomes in adductor SD.
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