BLOOD-BRAIN-BARRIER INTEGRITY IN ALZHEIMERS-DISEASE PATIENTS AND ELDERLY CONTROL SUBJECTS

A defective blood-brain barrier (BBB) has been postulated to be presen t in Alzheimer's disease (AD), which would allow circulating beta-amyl oid peptide to enter the brain. The authors tested this hypothesis by studying BBB function in 14 individuals with probable AD and 9 elderly control subjects. A computed tomographic method was used to measure b lood-to-brain transport (K-1), tissue-to-blood efflux (k(2)), tissue p lasma space (V-p), and tissue extracellular space (V-e) of meglumine i othalamate. Repeated-measures analysis of variance indicated no signif icant differences between the groups for any of the measures. The auth ors conclude that there is no generalized abnormality of the blood-bra in barrier in AD.