Cerebral Vascular Reserve in Small Vessel Disease and Alzheimers Disease

Alzheimers disease and cerebral small vessel disease have a considerably overlap in patients and have common risk factors. The diseases are difficult to separate in individual patients and we hypothesize that a reduced cerebral vascular reserve may be a measurement of small vessel disease independent of Alzheimers disease. Patients with presumed Alzheimers disease (n=20), cerebral small vessel disease (n=20) and healthy age-matched subjects (n=15) are examined with quantitative \[15O\]H2O positron emission tomography (PET) for measurements of brain perfusion before and after diamox infusion that dilates cerebral vessels. Additional \[15O\]H2O PET scans of the heart allows for a non-invasive input function so the cerebral vascular reserve can be measured quantitatively.