For some time, excessive daytime drowsiness and napping has been regarded as one of the earliest signs of Alzheimer’s. It was argued that daytime naps were a consequence of poor night’s sleep (common for Alzheimer’s patients). However, new research shows that the tau tangles characteristic of Alzheimer’s directly attack the brain regions responsible for maintaining daytime alertness. Hence, excessive daytime napping can indeed be seen as an early warning sign of the onset of Alzheimer’s.

Here are three media articles and a university post:

Alzheimer’s disease destroys neurons that keep us awake

Alzheimer’s Appears to Attack The Neurons That Keep Us Awake

Alzheimer’s disease destroys neurons that keep us awake

Alzheimer’s Disease Destroys Neurons that Keep Us Awake

Here is the research publication [paywall]:

Profound degeneration of wake-promoting neurons in Alzheimer’s disease

All links have been added to Neuro-Psych.