Inspiratory activation of the vocal cord adductor, which causes paradoxical vocal cord motion, develops in patients with multiple system atrophy (MSA). To confirm the hypothesis that airway reflexes trigger such paradoxical activation, we investigated the effects of tracheostomy on the adductor activation in a MSA patient.
We compared the adductor electromyograms before and after breathing was diverted to a tracheostoma under propofol anesthesia.
The adductor inspiratory activation disappeared during tracheostoma breathing.
Airway reflexes as well as MSA-related damage to the respiratory center contribute to the generation of paradoxical adductor activation in MSA patients.