Abstract
Introduction: Exercise induced vocal cord dysfunction (VCD) is a common condition, often confused with exercise induced asthma with unfortunate consequences. The evidence base for conservative treatment is limited but two single-case reports suggest effects from inspiratory muscle strength training (IMST).
Objectives: To run a pilot study that objectively visualizes laryngeal response pattern(s) to controlled training with IMST.
Methods: Ten healthy volunteers (range 21-26), were examined at rest with video recorded continuous transnasal flexible laryngoscopy while performing a standardized training program using a resistive loading device (Respifit S). The resistance during the training sessions were set at maximal and 60-80% of the maximal attainable inspiratory mouth pressure (PImax). Laryngeal movements were scored by a senior laryngologist according to a preset scheme.
Results: Resistance set at 60-80% of PImax produced a measurable glottic abduction in all subjects. Increasing the inspiratory pressure to PImax, revealed no change in the abduction in seven subjects, while in two subjects abduction appeared to decrease. In one subject a paradoxical adduction was observed. Supraglottic adduction was seen in two patients at PImax. In all subjects larynx moved downwards during inspiration, and nine of ten subjects seemed to engaged all muscle groups in the hypopharynx during inspiration at PImax.
Conclusion: The study suggests that IMST may be an efficient tool in the treatment of exercise induced VCD. Large interindividual differences suggest a need for individual training programs, and underscores that objective methods must be used during instructions and training with IMST in these patients.
- © 2011 ERS