Relationship of botulinum dosage to duration of side effects and normal voice in adductor spasmodic dysphonia
Objective
Objective evaluation of botulinum toxin A (BTX-A) dosing by determination of the statistical relationship between injection amount and duration of side effects and normal voice in adductor spasmodic dysphonia (SD) patients. From this information, to provide a rational guide to determine the initial and follow-up BTX-A amounts for injection.
Study Design and Setting
Private laryngology clinic. Statistical analysis was performed on data obtained from 101 patients with SD.
Results
Significant and predictable positive correlations were found between duration of side effects and duration of normal voice after BTX-A injection in patients with SD. Dose of BTX-A injected also appeared to have a significant positive correlation with duration of side effects, but a negative correlation with duration of normal voice. A trend toward more severe side effects was seen with larger doses of BTX-A injections.
Conclusions and Significance
Increased understanding of the response of the human voice over time after BTX-A injection at various doses suggests new ideas to further increase clinical efficacy with the use of lower BTX-A doses.
aFauquier Ear, Nose, and Throat Consultants, PLC, Warrenton, VA
Reprint requests: Christopher Y. Chang, MD, Fauquier Ear, Nose, and Throat Consultants, PLC, 550 Hospital Drive, Warrenton, VA 20186.
1 Dr Thomas spoke about botulinum toxin A at a meeting on April 2, 2006, the expenses of which were paid for by Panacée Counseil Inc, and he received an honorarium from Schering Canada. The referral for speaking was made by an employee of Allergan Inc. Paper subject has not been previously presented.
ABSTRACT