A skin patch stuck on the face at night could increase the time spent in deep sleep – which is vital for protecting the brain against stress, depression and possibly even dementia.
The high-tech patch, called NEUSLeeP, is programmed to beam low-intensity sound waves through the skull into the subthalamic nucleus, the part of the brain responsible for deep, or REM (rapid eye movement), sleep.
The sound waves are thought to stimulate activity in cells in the region, helping to keep the brain in REM sleep for longer. At the same time, sensors built into the face patch measure electrical signals associated with sleep – including brain activity, eye movements and muscle response – to monitor the treatment’s impact on REM rest.
During REM sleep, muscles in the arms and legs become temporarily paralysed – to stop us acting out dreams – and there is a natural rise in heart rate, blood pressure, breathing and brain activity during the ‘dreaming’ phase.
But REM sleep is also essential for keeping the brain in good health. It’s the time when the brain processes emotional experiences, stores memories and boosts its problem-solving abilities.
Studies show that too little of this deep sleep is linked with an increased risk of depression, as the brain is ill-equipped to process emotional memories.
A 2017 study in the US found that a lack of REM sleep also increased the risk of dementia.
This skin patch, called NEUSLeeP, beams low-intensity sound waves through the cheek and into the brain which helps to keep it in deep, or REM (rapid eye movement), sleep for longer
Studies show that too little REM sleep is linked with an increased risk of depression (picture posed by model)
Researchers at Boston University School of Medicine tracked 351 healthy people in their 60s, studying their sleep patterns at night to analyse the REM phases.
Almost one in ten went on to develop dementia and, in those who did, average REM sleep times amounted to just 17 per cent of total sleep – compared to 20 per cent or more in those free of dementia.
They also had longer intervals between REM sleep episodes (an average of 87 minutes compared to 70 minutes), suggesting the onset of REM was slower.
It’s not yet clear if disrupted deep sleep causes dementia, or is an early warning sign of the condition. But sleep loss generally – not just REM – is also known to be a risk factor for the condition, which affects nearly a million Britons.
The new face patch, developed by scientists at the University of Texas at Austin, is made from a soft, gel-like material and covers one side of the face.
In the middle of the patch there is a tiny generator designed to be level with the subthalamic nucleus deep inside the brain.
When the electrically powered patch is switched on, sound waves pass harmlessly through the cheek and into the brain, where they ‘excite’ neurons (nerve cells) in the subthalamic nucleus. Scientists chose ultrasound because sound waves can penetrate deeper into the body than other forms of energy, such as magnetic pulses.
Dr Kirstie Anderson, a consultant neurologist at Newcastle upon Tyne NHS Foundation Trust
Meanwhile, extending out from the patch are four ‘arms’, each with an electrode at the end to pick up electrical signals used to measure how soon REM sleep began after bedtime and how long each episode lasted.
Researchers tested the face patch on 28 healthy volunteers while they spent several nights in a sleep laboratory. The results, published recently in Nature Communications, revealed that using the patch increased the total amount of REM sleep through the night by almost 5 per cent. It also cut the time it took for volunteers to start their REM sleep cycles by 24 per cent – or 43 minutes.
Researchers now plan to set up larger trials to see if the patch can improve the symptoms of depression, anxiety and even post-traumatic stress disorder by increasing patients’ REM.
Dr Kirstie Anderson, a consultant neurologist at Newcastle upon Tyne NHS Foundation Trust, said the skin patch research was ‘interesting’ but stressed the relationship between REM sleep and mental health is far from clear-cut.
She told Good Health: ‘One key theory of depression is that people actually enter REM sleep too early – a lot of antidepressants even decrease or delay REM.
‘So it is really hard to say whether increasing REM is good or bad for you [in terms of mental health] although people do report better sleep quality with more REM.’
She said the size of the patch – it hooks behind one ear, covers the whole cheek and the arms extend up to the forehead and down to the chin – could put some patients off.
The drop-out rate among patients who wear a mask at night, through which pressurised air is pumped to treat sleep apnoea (where breathing is interrupted during sleep), is up to 50 per cent within the first year.
Dr Anderson said: ‘People dislike wearing things on their face or head [during sleep]. This is a big issue when people with sleep problems come to stay in our laboratory overnight or take equipment home.’
