Fig. 5

Relationship between cervical (spinal) CSF stroke volume and blood stroke volume. Correlation between oscillating cerebrospinal fluid (CSF) volume during one cardiac cycle (in milliliter per cardiac cycle [ml/cc]) at the cervical level (spinal CSF stroke volume [SV]) and blood stroke volume (SV blood) at intracranial and extracranial levels in the young and elderly. There is a moderate and significant correlation between spinal CSF SV and Extra blood SV in young volunteers (a) and in the elderly population (b). Spinal CSF SV and Intra blood SV did not correlate in young subjects (c) or in elderly subjects (d)