Dolichols are elevated in brain tissue from Alzheimer's disease, but not in urinary sediment from Alzheimer's disease and Down's syndrome.

Long-chain polyisoprenoid alcohols (dolichols) were measured in different brain regions dissected postmortem from 26 histopathologically confirmed cases of Alzheimer's disease and 24 age-matched nonAlzheimer control patients. They were significantly elevated in all parts of the cerebrum, but not in the cerebellum, of Alzheimer patients. The highest values were found in the temporal cortex and hippocampus. Out of the individual dolichol molecular species, the one with the most isoprene units (C105) was significantly increased in the temporal cortex, hippocampus, and basal forebrain of Alzheimer patients, compared with the controls. Dolichols were normal in the urinary sediment of 10 Alzheimer patients and nine patients with Down's syndrome, in comparison to age-matched controls for both groups. This is in contrast to neuronal ceroid-lipofuscinosis patients in whom dolichols are elevated in cerebral cortex, as well as in the cells of the urinary sediment, indicating generalized ceroid-lipofuscin storage.