The Way You Breathe Could Reveal a Hidden Sign of Alzheimer's

Earlier, more reliable Alzheimer's disease detection means better post-diagnosis support and more opportunity to understand how it gets started.

Researchers from the UK and Slovenia have now found specific brain activity and breathing patterns can act as signs of Alzheimer's.

The team set out to study how oxygenation of the brain might be linked to neurodegenerative diseases, comparing measures of brain oxygenation, heart rate, brain waves, and breathing effort of 19 Alzheimer's patients to 20 people without Alzheimer's.

Their analysis found differences in neurons linked to blood vessels and in how blood oxygen levels fluctuated as neurons fired. The sync of blood flow and brain activity seems to be noticeably disrupted in Alzheimer's brains.

What's more, there was an unexpected extra: the Alzheimer's patients had a higher breathing rate than the control patients, around 17 breaths per minute compared to 13 breaths per minute. This is possibly a result of changes in how blood vessels in the brain connect with deeper nerve tissues to provide a generous supply of oxygen.

"This is an interesting discovery – in my opinion a revolutionary one – that may open a whole new world in the study of Alzheimer's disease," says biophysicist Aneta Stefanovska, from Lancaster University in the UK.

"It most likely reflects an inflammation, maybe in the brain, that once detected can probably be treated and severe states of Alzheimer's might be prevented in the future."

The setup for the analysis involves a variety of electrical and optical sensors on the scalp – but it doesn't require any blood or tissue samples, and is cheaper and quicker than a lot of other diagnosis options.

And while breathing patterns on their own wouldn't yet be enough to detect Alzheimer's, with so many other variables in play, researchers can now look at respiratory rates in future studies to build up a more complete picture of Alzheimer's symptoms.

This supports the hypothesis that Alzheimer's disease is triggered by a breakdown in the functioning of the brain's vascular system, which reduces the efficiency of oxygen flow and clearance of toxic materials.

"The vascular system and the brain work together to ensure that the brain receives sufficient energy," says neurologist Bernard Meglič, from the University of Ljubljana in Slovenia.

"In fact, the brain needs as much as 20 percent of the body's overall energy consumption despite contributing only about 2 percent of the body's weight."

There's much to consider with Alzheimer's – from symptoms to risk factors – that it's likely that a combination of causes are working in combination, but research like this helps get us closer to understanding the disease's progression.

"We show clear results of our approach and how Alzheimer's can be detected simply, noninvasively, and inexpensively," says Stefanovska.

"The method has great potential, and we are discussing possibilities to create a spin-out or start-up company to proceed with it. Of course, more research is needed."

The research has been published in Brain Communications.