Anja Hayen1,2, Mari Herigstad1,2, Richard G. Wise3, Kyle T. S. Pattinson1,2
1Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, Oxfordshire, United Kingdom; 2Oxford Centre for Functional Magnetic Resonance Imaging of the Brain, Oxford, Oxfordshire, United Kingdom; 3School of Psychology, Cardiff University, CUBRIC, Cardiff, United Kingdom
Altered intrathoracic pressure affects cerebral blood flow (CBF) and may confound CBF based measurements of neuronal activity. In 13 healthy human volunteers, with transcranial Doppler (TCD) and ASL, we evaluated the effects of inspiratory and expiratory loading on CBF, and upon the stimulus-evoked CBF response. Transient effects of CBF were observed for 30 seconds following load application that subsequently normalised to baseline. The stimulus-evoked CBF response was unaltered. Therefore, altered intrathoracic pressure seen in respiratory disease is unlikely to adversely affect CBF. We conclude that longer stimulus blocks are better suited for volunteer models investigating neural processing of breathlessness perception.