Most of us probably think of sleep as shutting down for the night – but it’s just as busy for our brains as being awake. During deep sleep, our brain sorts out what to store in our long-term memory (like our best friend’s birthday) and what to discard (like that radio jingle or what we had for lunch last Tuesday). To mark Dementia Awareness Week, Liz Coulthard, Professor of Cognitive Neurology at the Bristol Medical School, explains how this night-time neural activity has informed her ground-breaking research into Alzheimer’s Disease. Snorers read on…
Why poor sleep could be putting your brain at risk
There’s now really clear evidence that poor sleep is linked to a higher risk of developing dementia. We don’t fully understand all the reasons yet, but there’s a very prominent hypothesis that the deep, slow-wave sleep (the kind we get earlier in the night) helps the brain to clear out amyloid and tau proteins. These are the same proteins that build up in the brains of people with Alzheimer’s.
If that deep sleep is disrupted or cut short, it may interfere with the brain’s ability to do this essential ‘cleaning’ process. And over time, that could be one of the factors that increases the risk of dementia.
Why snoring might be more serious than you think
Sleep apnea (sleep disordered breathing), often linked to snoring, is another important piece of the puzzle. People with moderate sleep apnea are actually deoxygenated at least 15 times an hour while they sleep. That triggers micro-awakenings – tiny interruptions that you might not even be aware of, but that stop you reaching the deeper stages of sleep. We think that’s particularly harmful for the brain.
We’re launching a major study across six UK sites to explore this further. There’s already quite convincing data suggesting that sleep apnea increases dementia risk. We don’t yet have the data to show that if we treat it, we slow down dementia. So, we’re at a really important point for clinical research.
The Bristol Brain Centre: research and care side by side
The Bristol Brain Centre brings together clinical care and research under one roof, so people coming to us with memory or cognitive concerns get expert care as well as the chance to take part in cutting-edge research. I lead the ReMemBR group (Research into Memory, the Brain and Dementia) comprising neurologists, psychologists and researchers. Everyone brings something different, and that’s key to both our care and our research.
We focus on early diagnosis, because we believe that gives people the best chance of preserving their future brain health. We haven’t yet got a proven way of putting that into practice so as to actually reduce people’s risk of dementia and improve quality of life. So, we want to take the laboratory findings, test them in clinical populations and then find out what works.
How early diagnosis has become a game-changer
Since I started working in this field, I’ve seen huge developments in our ability to diagnose. We’re one of the only services, certainly in the south west, using fluid biomarkers through lumbar punctures to test spinal fluid for amyloid and tau, enabling us to detect Alzheimer’s earlier. And a new blood test has just become clinically available, which could soon mean fewer invasive tests. While diagnosis is getting easier for Alzheimer’s, other dementias like Lewy body can still be tricky to pick up early, especially when Parkinson’s-like symptoms haven’t appeared yet. So there’s still more to do.
Where AI might come in
What’s exciting is we’re now using artificial intelligence to personalise sleep advice. In one study, we tracked people’s activity, light exposure, noise and so on, then used AI to spot patterns: for example, someone might consistently sleep worse after using screens late at night. That kind of insight could help us offer individual advice to improve sleep and possibly reduce risk.
We’re also hoping to work with colleagues at Cambridge using AI to analyse clinical data and flag people who are more likely to have Alzheimer’s, so that we can prioritise further testing where it’s needed. It’s promising.
Dementia isn’t inevitable and there’s a lot we can do
I think it’s important for people to know that dementia isn’t an inevitable part of ageing. There are real, proactive things we can all do to reduce risk, like managing blood pressure, staying mentally and physically active, eating well, limiting alcohol and getting quality sleep. People still fear a diagnosis, but early assessment is where we can make the biggest difference and offer treatments that we think might improve the quality of life to people who already have it.
The sooner we see people, the more we can help.
More inclusive research and care
The University can really help to raise awareness of dementia by speaking in ways people understand, involving patients and the public in research, and raising awareness in underrepresented communities. Right now, certain groups aren’t even making it into clinic, so they’re missing out on care and trials.
Dementia carries a stigma, and we can work to highlight the fact that being assessed for memory is a useful thing. There are things we can do to try and delay dementia and to improve cognition. So demystifying the process is helpful for everyone.
Why dementia research is a brilliant career path
Dementia research is such a rewarding field to be part of, and there are so many different avenues you can pursue. There’s a thriving laboratory research team at Bristol, but all around the country there’s an increasing recognition that neurodegenerative disease is one of the last frontiers of medicine that we really haven’t cracked yet. So, you get to be part of a growing business, as it were.
There’s a real lack of people in a position to implement laboratory findings in the population, so I’d really encourage clinical researchers to get involved in this direction. It’s a privileged position where you get to work closely with all sorts of people including patients, medical doctors and scientists, and I hope we’ll be able to offer more positive treatments as we go on over the next few years.
You can find out more about Professor Coulthard’s work via the University’s research pages.
