Transcranial Doppler to measure cerebral blood flow in delirium superimposed on dementia. A cohort study.

Objective: Delirium superimposed on dementia (DSD) is frequently not diagnosed, at great cost. Both delirium and dementia are associated with cerebral hypoperfusion. A switch to anaerobic glycolysis in the central nervous system during delirium compared to Alzheimer's dementia (AD) suggests greater hypoperfusion in DSD.