Influence of respiration frequency and depth on the flow of CSF in the spinal canal

Cerebrospinal fluid (CSF) movement in the spinal canal is generated by several driving mechanisms, such as the periodic intracranial pressure changes associated with the cardiac cycle or the ventricular CSF production. Additionally, over the past few years, respiration has been identified to play a relevant role in this motion. This influence has been investigated in different studies, most of which focused on forced respiration and highly non-cyclic breathing maneuvers, such as coughing and sniffing.

In this work, we present measurements of CSF flow during normal, controlled, respiration using real-time MR imaging at the cervical and lumbar level, synchronized with measurements of respiratory flow rate. We examine the influence of different respiration frequencies and depths on the induced CSF velocities. Our results reveal the existence of a clear effect of respiratory period and intensity on the induced CSF flow and associated stroke volume, especially in the lumbar region, where it is found to be the dominant driving mechanism.