Cortical CSF volume fluctuations by MRI in brain aging, dementia and hydrocephalus.

Dynamic MR imaging has revealed dramatic fluctuations in the appearance of CSF in the cortical sulci and cortical subarachnoid spaces in aging individuals and patients with hydrocephalus, dementia and Down syndrome in contrast to young healthy volunteers. The changes have been interpreted as volume fluctuations that represent undamped CSF hydrodynamics and have implications with respect to the origin of CSF in the cortical regions and with respect to the similarity between aging and dementia and edematous states of the brain.