Needing to nap could be an early warning sign of Alzheimer’s disease, according to new research.
Experts found that the brain cells that keep us awake during the day are among the first to be targeted by the neurological disease.
It was previously thought the cells were destroyed by a protein called beta-amyloid, but scientists have now concluded the culprit is toxic clumps of a protein called tau.
They say the discovery could lead to earlier diagnosis when drugs and lifestyle changes are more likely to work and may also lead to better treatments.
Regular dozing in patients has been reported by both researchers and caregivers long before their memory problems begin to unfold.
But it was unclear if disturbed sleep put people at risk of Alzheimer’s — or if disease-related brain changes lead to it.
The team at the University of California at San Francisco analyzed the brains of 13 deceased patients who had Alzheimer’s disease at the time of death.
They found the three brain areas that boost wakefulness — the locus coeruleus, lateral hypothalamic area and tuberomammillary nucleus — had lost as many as 75 percent of their neurons.
They also had a significant buildup of tau. The results are significant as they could lead to better treatments by targeting tau instead of beta-amyloid.
It also provides a reason for the regular dozing reported by Alzheimer’s patients and their caregivers, long before the development of memory problems. The research was published in Alzheimer’s & Dementia.
Lead author Dr. Jun Oh, based at the Memory and Ageing Centre at UCSF, said: “It is remarkable because it is not just a single brain nucleus that is degenerating, but the whole wakefulness-promoting network.
“Crucially this means the brain has no way to compensate because all of these functionally related cell types are being destroyed at the same time.”
Alzheimer’s can take root up to 20 years before symptoms appear and it’s believed existing medications are failing because they are given to patients far too late.