Differences in botulinum toxin dosing between patients with adductor spasmodic dysphonia and essential voice tremor.
OBJECTIVE
To explore possible dose differences in average botulinum toxin (BTX) given to patients with adductor spasmodic dysphonia (ADSD) compared with patients with essential voice tremor (EVT).


METHODS
A retrospective study compared the average BTX dose injected in equal doses to the thyroarytenoid (TA) muscles of 51 patients with ADSD with 52 patients with EVT.


RESULTS
Those with ADSD received significantly higher total doses (6.80 ± 2.79 units) compared with those with EVT (5.02 ± 1.65 units). Dose at time of first injection, age at time of first injection, gender, year of first injection, and average time between injections were included in multivariate analysis but did not interact with total average dose findings.


CONCLUSIONS
Patients with ADSD may need relatively higher doses of BTX injections to bilateral TA muscles compared with patients with EVT.
Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota; Division of Speech Pathology, Department of Neurology, Mayo Clinic, Rochester, Minnesota. Electronic address: dmorbelo@gmail.com.
Diana M
DM
Orbelo
Division of Speech Pathology, Department of Neurology, Mayo Clinic, Rochester, Minnesota.
Joseph R
JR
Duffy
Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota.
Becky J
BJ
Hughes Borst
Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota.
Dale
D
Ekbom
Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota.
Nicolas E
NE
Maragos
D001905:Botulinum Toxins / Q000008:administration & dosage*; D016009:Chi-Square Distribution; D054796:Drug Dosage Calculations; D055154:Dysphonia / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D007273:Injections, Intramuscular; D007821:Laryngeal Muscles / Q000187:drug effects* / Q000503:physiopathology; D015999:Multivariate Analysis; D009465:Neuromuscular Agents / Q000008:administration & dosage*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014833:Voice Quality / Q000187:drug effects*
D009465:Neuromuscular Agents; D001905:Botulinum Toxins
Botulinum toxin; Dystonia; Dystonic tremor; Essential voice tremor; Spasmodic dysphonia; Tremor