It is not clear if you are referring to respiratory muscle dystonia or to laryngeal dystonia. Respiratory muscle dystonia could involve the diaphragm and/or the accessory muscles used with breathing. Laryngeal dystonia affects the laryngeal muscles and is seen with VCD (vocal cord dysfunction) or laryngospasm. Please read our Vocal Cord Dysfunction MedFact at http://www.nationaljewish.org/medfacts/vocal.html for more information.
The relief may or may not be related to an adrenalin rush. If it is, it might be due to relief of laryngeal edema.
You should consult with a speech therapist knowledgeable about VCD and then with an ENT who has worked with the therapist.