Etiology
This syndrome results from irregular and inappropriate contractions of the adductory muscles of the larynx. It typically presents with audible sounds during inspiration. It is quite often mixed with adductory SD. Don’t be surprised if the patient has had many previous diagnoses. The true cause of the condition remains unknown.
Diagnosis
History
Typical complaints
- breathing and voice problem
- breathing cuts off at night or hard to fall asleep
- difficult or noisy breathing when excited
- instability
- unpredictability
- good days and horrible days
- I have seen several doctors and they say nothing is wrong with me
- Stress makes it worse
- May be associated with previous head trauma
Character of a patient with respiratory dystonia
- Patients are often frustrated because of the long period of time between the onset of their disorder and the correct diagnosis.
- They may have been told in the past that their problem was psychogenic, polyps, allergies, anxiety or even paralysis.
- The disorder is highly variable and they may indeed present on a day when their spasms are almost nonexistent.
- Talkativeness scale: whole range
Vocal capabilities
- Deep inspiration
- spasms may become more pronounced
- inspiratory noise
- Prolonged vowel phonation
- respirations may improve with distraction.
Laryngeal Exam
- Neck exam
- other cervical muscles may contract during inspiration
- rigid laryngoscope
- general unsteadiness with random contractions of supraglottis and glottis, especially during inspiration
- flexible laryngoscope
- during inspiration spasms of the adductory muscles may be noted with inadvertent closure of the glottis
- glottis may be almost tonically closed
- Sniffing will often relieve spasms and a normal abduction will be noted.
Treatment
Medical
- botulinum toxin injections into thyroarytenoid muscles
- Our average starting dose is 1.8 units total divided equally between each thyroarytenoid.
- Our average dose is 2.5 units total. Our range of dosing is .7 units to 10 units total dose.
- The dose does not seem to be related to body size, age or severity of dystonia.
- Thus the first two injections are trial doses to determine the ultimate dosing schedule.
- Duration of the effect is a median of 16 weeks with an approximate range of eight to twenty six weeks.
- There is no direct correlation between size of dose and duration of effect
- Patient information
|
