Alzheimer’s and the Sleep Cycle

It is well-known that people with Alzheimer’s have difficulty with sleep. One of the areas the disease attacks is the sleep/wake center of the brain called the suprachiasmatic nucleus. This results in severe problems with the timing of falling asleep and waking up – thus the link between Alzheimer’s and the sleep cycle. This can become maddening for family members and caregivers trying to cope with nighttime wanderings and people who sleep most of the day.

Interestingly, several recent studies have shown that lack of sleep or poor quality sleep may be a cause of Alzheimer’s. The culprit is a protein called beta-amyloid. Beta-amyloid is the substance that forms the destructive plaques that progressively destroy the brains of those with Alzheimer’s. In the studies, normal subjects were followed at night using sleep diaries as well as a device called an actigraph that can show whether one is asleep or not. Those people who either slept six and one-half hours or less or spent less than 85% of time in bed asleep were more likely to show elevated levels of beta-amyloid in their brain fluids. They also tended to show early evidence of plaque formation on brain scans.

So the question is, can lack of sleep contribute to the development of Alzheimer’s? The jury is still out. There are those who argue that the early plaque formation and elevated beta-amyloid may be causing the sleep disturbance. It’s the old chicken and the egg argument. However, it would seem to me from the studies that it is likely that insufficient and poor quality sleep may be involved in the development of Alzheimer’s. The resulting message is that once again we see the consequences of poor sleep. When we don’t get enough sleep, everything from diabetes to heart disease increases. Now we have evidence that even dementia may be related to poor sleep. Accordingly, if you can, try to sleep at least seven to eight hours a night. If you can’t, then seek help.

By Robert Rosenberg