A new study from the Netherlands has looked at the effectiveness of a new sleep seizure detection device. The device – Nightwatch – is a bracelet worn on the arm. It uses heart rate and movement to sense what the authors called ‘major’ seizures.
For their study, the researchers considered ‘major seizures’ to be those that were clinically urgent. They included tonic-clonic, long generalised tonic and intense motor seizures which they call hyperkinetic seizures. They also included other major seizures which were not typical, such as clusters of myoclonic or tonic seizures. Epilepsy Action has more information on different types of seizures.
The study was carried out between 2015-17 on 28 people with epilepsy and a learning disability who had more than 1 sleep seizure in a month. People taking part were residents in epilepsy centres and were studied for 2-3 months. They were also filmed during this time, so researchers could see when the device did and did not sense major seizures.
The study covered 1,826 nights and 809 major seizures. The device could sense over four-fifths (85%) of major seizures in each participant. This was compared to a bed sensor, which recognised one-fifth (21%) of these seizures.
The developer of the device, Livassured BV, said this device has a much better sensitivity than other technology currently available.
The researchers also measured how often the Nightwatch wrongly sensed a seizure when there wasn’t one. Out of the alerts from the device, 49% were real major seizures, which the researchers called ‘reasonable’. The device very rarely missed a major seizure.
Study authors Dr Johan Arends and colleagues explained that having uncontrolled seizures is a risk factor for sudden unexpected death in epilepsy (SUDEP). Epilepsy Action explains that different groups of people with epilepsy are at a different risk.
While SUDEP is still poorly understood, researchers believe it could be related to breathing or heart problems during a seizure. Research suggests that cases of SUDEP tends to happen overnight and it is often unwitnessed. Anyone affected by SUDEP can find links to useful organisations on the Epilepsy Action website. The researchers in the study suggest that this sensor could help in preventing SUDEP.
However, critics say that night-time monitoring systems won’t help people who live alone or don’t have a carer. Doctors caution that the medical devices field is not as well regulated as the medicines field, and that not enough is known to recommend one device over another. They warn that it's important to be aware that the devices don't recognise 100% of seizures and that they can also be too sensitive.
To get the Nighwatch in the UK, the cost is £1,130 including shipping. Livassured also offers a money back guarantee. It explained that despite the good results, it may still be too sensitive or not sensitive enough for an estimated 1 in 10 people. The company said it offers the money back guarantee because it does not want people making an investment that doesn’t bring a considerable improvement to their situation.
This technology has been developed by scientists from the Netherlands and has taken over 20 years.