Respiratory Modulation of Cerebrospinal Fluid Flow During Paced Breathing

We used flow-sensitive fMRI to explore the effect of paced respiration on cerebrospinal fluid (CSF) flow. Results indicate that paced breathing tasks at rates between 0.1 Hz and 0.25 Hz increase CSF flow. All breathing paces showed a striking increase in CSF inflow-enhanced signals with the highest group-averaged amplitude being 26% during the 0.1 Hz breathing task. We conclude that diaphragmatic paced breathing is an effective modulator of CSF flow that may represent increased fluid transport relative to free breathing.