David Lawi1, Elise Dupuis-Lozeron2,3, Gregory Berra1, Gilles Allali3,4,5, Thomas Similowski6,7, Dan Adler8,3. 1. Division of Pulmonary Diseases, Geneva University Hospitals, Geneva, Switzerland. 2. Clinical Research Centre and Division of Clinical Epidemiology, Dept of Health and Community Medicine, Geneva University Hospitals, Geneva, Switzerland. 3. University of Geneva Faculty of Medicine, Geneva, Switzerland. 4. Dept of Neurology, Geneva University Hospitals, Geneva, Switzerland. 5. Dept of Neurology, Division of Cognitive and Motor Aging, Albert Einstein College of Medicine, Bronx, NY, USA. 6. AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, Intensive Care Unit and Respiratory Division (Département "R3S"), Paris, France. 7. Sorbonne University, UPMC Paris 06, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, France. 8. Division of Pulmonary Diseases, Geneva University Hospitals, Geneva, Switzerland dan.adler@hcuge.ch.
Abstract
BACKGROUND: Chronic respiratory diseases are associated with cognitive dysfunction, but whether dyspnoea by itself negatively impacts on cognition has not been demonstrated. Cortical networks engaged in subjects experiencing dyspnoea are also activated during other tasks that require cognitive input and this may provoke a negative impact through interference with each other. METHODS: This randomised, crossover trial investigated whether experimentally-induced dyspnoea would negatively impact on locomotion and cognitive function among 40 healthy adults. Crossover conditions were unloaded breathing or loaded breathing using an inspiratory threshold load. To evaluate locomotion, participants were assessed by the Timed Up and Go (TUG) test. Cognitive function was assessed by categorical and phonemic verbal fluency tests, the Trail Making Tests (TMTs) A and B (executive function), the CODE test from the Wechsler Adult Intelligence Scale (WAIS)-IV (processing speed) and by direct and indirect digit span (working memory). RESULTS: The mean time difference to perform the TUG test between unloaded and loaded breathing was -0.752 s (95% CI -1.012 to -0.492 s) (p<0.001). Executive function, processing speed and working memory performed better during unloaded breathing, particularly for subjects starting first with the loaded breathing condition. CONCLUSION: Our data suggest that respiratory threshold loading to elicit dyspnoea had a major impact on locomotion and cognitive function in healthy adults.
RCT Entities:
BACKGROUND: Chronic respiratory diseases are associated with cognitive dysfunction, but whether dyspnoea by itself negatively impacts on cognition has not been demonstrated. Cortical networks engaged in subjects experiencing dyspnoea are also activated during other tasks that require cognitive input and this may provoke a negative impact through interference with each other. METHODS: This randomised, crossover trial investigated whether experimentally-induced dyspnoea would negatively impact on locomotion and cognitive function among 40 healthy adults. Crossover conditions were unloaded breathing or loaded breathing using an inspiratory threshold load. To evaluate locomotion, participants were assessed by the Timed Up and Go (TUG) test. Cognitive function was assessed by categorical and phonemic verbal fluency tests, the Trail Making Tests (TMTs) A and B (executive function), the CODE test from the Wechsler Adult Intelligence Scale (WAIS)-IV (processing speed) and by direct and indirect digit span (working memory). RESULTS: The mean time difference to perform the TUG test between unloaded and loaded breathing was -0.752 s (95% CI -1.012 to -0.492 s) (p<0.001). Executive function, processing speed and working memory performed better during unloaded breathing, particularly for subjects starting first with the loaded breathing condition. CONCLUSION: Our data suggest that respiratory threshold loading to elicit dyspnoea had a major impact on locomotion and cognitive function in healthy adults.