Laryngeal
dystonia is a
movement disorder of the muscles within the larynx, which most commonly manifests as spasmodic
dysphonia (SD). Rarer reported manifestations include dystonic respiratory
stridor and dyscoordinate breathing. Laryngeal
dystonia has been treated successfully with
botulinum neurotoxin (BTX)
injections since 1984. We reviewed prospectively collected data in a consecutive series of 193 patients with laryngeal
dystonia who were seen at St. Vincent's Hospital between 1991 and 2011. Patient data were analyzed in Excel, R, and Prism. Laryngeal
dystonia manifested as SD (92.7%),
stridor (11.9%), dystonic
cough (6.2%), dyscoordinate breathing (4.1%), paroxysmal
hiccups (1.6%), and paroxysmal
sneezing (1.6%). There were more women (68.4%) than men (31.6%), and the average age at onset was 47 years. A positive family history of
dystonia was present in 16.1% of patients. A higher incidence of extra-laryngeal
dystonia (ie,
torticollis and
blepharospasm) and concurrent manifestations of laryngeal
dystonia were present in patients with dystonic
cough, dyscoordinate breathing, paroxysmal
sneezing, and
hiccups than in other patients (P = 0.003 and P < 0.0001, respectively). The average starting dose of BTX decreased from 2.3 to 0.5 units between 1991 and 2011. The median treatment rating was excellent across all subgroups. Patients with adductor SD,
stridor, extra-laryngeal
dystonia and male patients had relatively better treatment outcomes. Technical failures were rare (1.1%).
Dysphonia secondary to
vocal cord paresis followed 38.7% of treatments. Laryngeal
dystonia manifests predominantly as SD, but other manifestations include
stridor, dyscoordinate breathing, paroxysmal
cough,
hiccups, and
sneezing. BTX
injections are very effective across all subgroups. Severe adverse events are rare.