Reference Values of Cerebrospinal Fluid Outflow Resistance and Intracranial Pressure in Healthy Elderly

Objective. The intracranial pressure and cerebrospinal outflow resistance are essential parameters to describe the cerebrospinal fluid dynamic system. Outflow resistance effects intracranial pressure, pulse amplitudes, cerebrospinal fluid absorption as well as the compliance of the system. The objective of this study was to determine the reference values in the elderly.

Methods. Elderly people (60-82 years), considering themselves healthy, were recruited through an ad in the local paper. All were evaluated with a 3 Tesla magnetic resonance imaging apparatus. Subjects were eligible if they did not have any psychiatric or neurological disorder or signs of advanced atherosclerotic disease. Intracranial pressure and outflow resistance were determined by a constant pressure infusion method with the patient in the supine position. The study population consisted of 40 subjects (mean age 70 years; 23 women).