Patients of Alzheimer’s disease who experience one or more episodes of delirium have a more rapid decline in their mental capacities.
Delirium is a state of mental confusion in, which a person's speech becomes disordered and non-sensical and they experience hallucinations.
Researchers from America assessed changes in the cognitive performance over time in 2 groups of 408 patients with Alzheimer’s disease - 72 who developed delirium and 336 patients who did not develop delirium. Cognitive performance was measured in all the subjects and data regarding their age, sex, education and family history of dementia– its severity and duration of symptoms was also collected.
It was found that the speed of cognitive decline increased significantly after an episode of delirium. Prior to a delirium episode, the average cognitive performance decline based on a standard test was 3 points per year. After a delirium episode, the rate of decline became 5 points per year. Across the 2 groups, the rate of change in memory concentration score occurred about 3 times faster in those who had delirium compared to those who did not.
Therefore, the researchers concluded that delirium could accelerate cognitive decline in patients with Alzheimer’s disease.