New deep brain stimulation could improve memory loss in Alzheimer’s patients

According to Alzheimer's Society, it is estimated that one in three people born in the UK will develop the neurodegenerative disease in their lifetime. Currently, there are 900,000 people in the UK living with some form of dementia, with this number expected to rise to 1 million by 2025.

The new technology has been successfully trialled with 20 healthy volunteers for the first time by Dr Nir Grossman and Dr Ines Violante and the team at the UK Dementia Research Institute (UK DRI) at Imperial College London and the University of Surrey.

Dr Richard Oakley, associate director of research and innovation at Alzheimer's Society, described the technology as ‘incredible’ and a promising alternative to invasive surgery.

“Currently, treatments that stimulate areas deep in the brain are used in Parkinson’s disease, but this involves invasive surgery which can take months to recover from,” he said.

“Dementia is a devastating terminal illness and the UK’s biggest killer, so it really is exciting to see research opening up whole new areas for future treatment, but it’s still very early days. We’re looking forward to seeing how the study develops, particularly how long-lasting the changes could be for people living with Alzheimer’s disease.”

Known as temporal interference (TI), the treatment works by safely delivering differing frequencies of electrical field through electrodes placed on the scalp and different parts of the head.

The overlapping electrical fields enable a deep region of the brain known as the hippocampus to be targeted by electrical stimulation, without affecting the surrounding areas – a procedure that previously required brain surgery.

In the initial study, the researchers applied TI stimulation to healthy volunteers while they were memorising pairs of faces and names – a process heavily dependent on the hippocampus.

The research, published in Nature Neuroscience,​ showed that the technology was able to focally stimulate the hippocampus and improve memory function in healthy adults.

Scientists now hope the technology could be used to help those suffering with Alzheimer’s disease, as well as accelerate the discovery of new therapeutic targets.

Study leader Dr Grossman commented: “Until now, if we wanted to electrically stimulate structures deep inside the brain, we needed to surgically implant electrodes into the brain, which of course carries risk for the patient, and can lead to complications.

“With our new technique we have shown for the first time, that it is possible to remotely stimulate specific regions deep within the human brain without the need for surgery. This opens up an entirely new avenue of treatment for brain diseases like Alzheimer’s which affect deep brain structures. We hope it will help to scale up the availability of deep brain stimulation therapies by drastically reducing cost and risk."

Moving forward, the researchers will begin trialling the technology with people in the early stages of Alzheimer’s disease.

In the upcoming clinical trial, funded by the Alzheimer’s Association and the Bill Gates Foundation, participants will receive multiple sessions of non-invasive TI brain stimulation, to test whether it could be effective at restoring activity in affected areas of the brain and improving symptoms of memory loss^.​

First author of the study, Dr Violate, described the breakthrough as ‘very exciting’ as it provides a tool to investigate how the human brain operates and opens new possibilities for clinical applications.

Dr Joanna Latimer, head of neuroscience and mental health at the Medical Research Council, added: "Alzheimer’s disease is a devastating condition for which effective treatments are very much needed. Memory impairment is a key feature of the disease and these initial results present an innovative treatment option for people diagnosed with Alzheimer’s.

“The results from the next stage of this highly promising treatment cannot come fast enough, and reaffirm the importance of the commitment the MRC has made to support the UK DRI and its role in advancing dementia research.”