A novel approach to deep brain stimulation offers a promising alternative for treating dementia without the need for surgery. Researchers at Imperial College London are leading the development and testing of this innovative brain stimulation technique, which has the potential to serve as an alternative therapy for brain diseases like Alzheimer’s, and its associated memory loss.
Temporal interference (TI)
Known as temporal interference (TI), this non-invasive method involves the delivery of electrical fields to the brain through electrodes positioned on the patient’s scalp and head. By precisely targeting the overlapping electrical fields, researchers can stimulate a specific deep brain area known as the hippocampus, all without affecting the surrounding regions. Traditionally, this kind of deep brain stimulation required surgical implantation of electrodes, making this new approach a groundbreaking development.
Promising dementia treatment
“This opens up an entirely new avenue of treatment for brain diseases like Alzheimer’s which affect deep brain structures,” says Dr Nir Grossman from the Department of Brain Sciences at the Imperial College London.
The research team has successfully conducted initial trials with 20 healthy volunteers, marking the first application of this technique. Their findings, published in the journal Nature Neuroscience, demonstrate that when healthy adults engage in a memory task while receiving TI stimulation, it enhances their memory function.
The next step for the team involves conducting clinical trials with individuals in the early stages of Alzheimer’s disease, with hopes that TI could improve memory loss symptoms.
Dr Nir Grossman, from the Department of Brain Sciences at Imperial College London, who led the work said: “Until now, if we wanted to electrically stimulate structures deep inside the brain, we needed to surgically implant electrodes 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.”
New therapeutic targets
TI was initially described by the Imperial College London team in 2017 and demonstrated in principle in mice. This latest research, funded and conducted through the UK Dementia Research Institute, establishes the effectiveness of TI in stimulating deep regions of the human brain. According to the researchers, this could pave the way for a wide range of applications and accelerate the discovery of new therapeutic targets by allowing scientists to selectively stimulate different deep brain regions to gain insights into their functional roles.
The investigation
In their investigation, scientists first employed post-mortem brain measurements to target electric fields onto the hippocampus, a curved brain structure situated deep within the brain known for its pivotal role in memory and learning.
Then, the research team applied TI stimulation to individuals without any medical conditions while they were in the process of memorising pairs of faces and names, a task highly reliant on hippocampal function. Using functional magnetic resonance imaging (fMRI), the researchers demonstrated that TI selectively affected the hippocampal activity triggered by the memory task.
Finally, the researchers replicated the procedure, extending the stimulation for a longer period of 30 minutes. TI stimulation during this task was found to improve memory accuracy.
What experts are saying
Dr Ines Violante, from the University of Surrey and Honorary Research Fellow at Imperial, and first author on the study, said: “The ability to selectively target deep brain areas using a non-invasive approach is very exciting as it provides a tool to investigate how the human brain operates and opens possibilities for clinical applications.
“The combination of non-invasive imaging and brain stimulation will help us unravel the processes that support our cognitive functions, such as memory and learning. Knowledge of these processes and how they can be altered is essential to develop better individualised strategies to treat or delay the onset of diseases.”
Dr Grossman added: “We hope this work will help to scale up the availability of deep brain stimulation therapies by drastically reducing cost and risk.
“We are now testing whether repeated treatment with the stimulation over the course of a number of days could benefit people in the early stages of Alzheimer’s. We hope that this will restore normal brain activity in the affected areas, which could improve symptoms of memory impairment.”
Other applications for TI technology
This study is released in conjunction with another research paper led by a team at École polytechnique fédérale de Lausanne (EPFL) in Switzerland, providing an independent validation of the technology.
In the EPFL study, also featured in Nature Neuroscience, the researchers harnessed TI technology to focally stimulate a different deep brain region known as the striatum and enhance motor memory function in healthy volunteers.
Participants in the clinical trial were enlisted through the NIHR Memory Centre and Imperial College Healthcare NHS Trust.
The research was financially supported by the UK Dementia Research Institute and received partial backing from the NIHR Imperial Biomedical Research Centre and the UKRI BBSRC.
Next clinical trial
Dr Leah Mursaleen, Head of Research at Alzheimer’s Research UK says: “Although there are some promising new drugs in the pipeline for people with early Alzheimer’s disease, they have not yet been approved by regulators and, even if they are, they may not be suitable for everyone. With nearly 1 million people living with the dementia in the UK today, it’s crucial that we also look at other ways that can help people manage their symptoms.
“Although deep brain stimulation is available as a treatment option for some brain conditions, such as Parkinson’s disease, current techniques require complicated brain surgery. So, it’s fantastic to see UK-based researchers exploring promising new ways to reach the brain that don’t require invasive procedures.
“It is important to note that this study was done in a small group of healthy volunteers. Therefore, the results of the next clinical trial, which will assess this exciting technique in people with early Alzheimer’s disease, will give us more insight to see if this technique can help improve their memory.”
Final thought
In the world of medical innovation, non-surgical brain stimulation, led by Imperial College London, could promise a revolution in dementia treatment. This technique, using temporal interference, non-invasively targets deep brain regions, a groundbreaking alternative to surgery and medicine. While initial tests with healthy volunteers show promise, the true test lies in clinical trials involving early-stage Alzheimer’s patients.
Curia’s Dementia Commission:
Curia’s Dementia Commission brings national, regional and local leaders together to implement a plan to set out a plan to improve the life chances of all people living with dementia and other neurodegenerative conditions. A panel of Commissioners with a specialism in neurodegeneration will be convened to help the Curia research team produce solutions to improve implementation. Case studies on neurodegenerative conditions and good examples of best practice will feature at a series of inquiry sessions and in the final report.
Four roundtable inquiries will create a vision for what the environment needs to look like to support people with neurodegenerative conditions, namely dementia and be ready for future treatment pathways. The roundtables will produce recommendations for how outcomes can be improved. Stakeholders will include clinical leads, commissioners and regulators including NICE, NHS England and patient organisations. Each roundtable will have a remit to look at how pre-existing policy can be implemented, identifying where gaps exist in the policy landscape and setting a series of recommendations to explore the improvement in the system for patients with a neurodegenerative condition.
Curia will publish the findings at a Parliamentary launch alongside the reports from roundtables to ensure maximum engagement.
