Excessive daytime naps could signal Alzheimer's disease

Alzheimer's disease or senile dementia is a condition characterised by degeneration of brain cells, which eventually leads to memory loss. New studies have revealed that excessive daytime sleepiness could be a potential symptom of Alzheimer’s disease.

In a research published by University of California San Francisco (UCSF), the scientists inferred that nerve cells that keep you awake tend to die when a protein forms tangles. They collected data from UCSF Neurodegenerative Disease Brain Bank.

 The researchers studied signs of Alzheimers’s disease in parts of the brain responsible for maintaining wakefulness in two groups- 13 deceased people who had Alzheimer’s disease and 7 people who did not have it. Those who had Alzheimer’s disease had a considerable growth of tau, a protein that helps transmit nutrients in brain cells.

When a person has Alzheimer’s disease, the protein tends to fall into masses called tangles. This restricts the flow of nutrients to the brain cells, eventually causing them to die. Thus, tau tangles are potential indicators of developing Alzheimer’s disease.

Joseph Oh, the lead author of the study says, “In this particular study, we were curious if a specific network within the brain stem and subcortical regions are affected in Alzheimer’s disease. We found that the network, which [promotes] wakefulness, is obliterated in Alzheimer’s disease.”

“Our lab was interested in looking at early pathological changes in the human Alzheimer’s disease brains, focusing on the brain stem and subcortical regions,” he adds. He explains that the areas of brain undertaken for study in this research had not received a lot of focus until now.

These findings echo the inferences drawn from an earlier study conducted by the Grinberg lab. People who died with increased levels of tau experienced drastic changes in their sleep pattern along with anxiety and depression.

“I think the extent of substantial neuronal loss in the wake-promoting centres was very surprising and, in a way, frightening,” Oh explained. “This is especially true because not just one type of neuron is affected, but an entire wake-promoting network.”

“This makes it difficult for the brain to compensate for the loss of function,” he said. “It shows how devastating Alzheimer’s disease really is to a person’s brain at a microscopic level.”

Dr Steven Lin, an expert in neurology and sleep medicine at Healthcare Associates in Medicine in New York stated that Alzheimer’s disease and sleep are linked to each other. “Poor sleep has also been associated with an increased risk of amyloid protein buildup in the brain, another protein associated with Alzheimer’s disease risk,” Lin explained.

A recent study carried out by University of California Berkeley psychologists pointed that people in their 50s and 60s with a decreasing sleep quality were found to have increased protein tangles in their brain. Getting adequate sleep is necessary for a healthy cognitive functioning, they warned.

“Insufficient sleep across the lifespan is significantly predictive of your development of Alzheimer’s disease pathology in the brain,” Matthew Walker, the study’s senior author and a sleep researcher said.

“Unfortunately there’s no decade of life that we were able to measure during which you can get away with less sleep,” Dr Walker said. “There’s no ‘Goldilocks decade’ during which you can say, ‘This is when I get my chance to short my sleep.’”

There is no clarity yet on whether tangles in tau cause lack of sleep or vice versa. However, here a few tips to help you get a good night’s sleep:

• Avoid consuming caffeine after evening.
• Schedule your sleep and stick to the clock.
• Expose yourself to an adequately bright environment during daytime.
• Go for yoga, exercising, or other workouts to aid sleepiness at night.
• Make sure you have a healthy diet.