Clinical trial: electrical brain stimulation

Landmark trial to treat dementia by sending electrical currents deep into the brain

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Dr Nir Grossman, Group Leader at UK DRI at Imperial, is leading a new innovative trial using deep electrical currents applied to the brain of people living with Alzheimer's disease.

Recruitment for the trial has now closed. To learn more about our ongoing trials, visit the Interventional Systems Neuroscience Lab website.

The project is funded by Alzheimer’s Association via Part the Cloud (PTC) grants program, in partnership with Bill Gates Foundation.

Hopes for the technology

The technology – called temporal interference brain stimulation – involves applying electrodes to the scalp. The electrodes then send two harmless high-frequency beams into the brain, which do not interfere with healthy brain tissue. These beams are of slightly different frequencies – 2,000 Hz and 2,005 Hz – and when they cross they create a third current, a low-frequency wave of 5 Hz.

It is this new wave which is hoped will make all the difference as it has the same frequency at which brain cells fire – allowing it to spark diseased neurones back into action. It will be triggered in the hippocampus – an area deep in the brain responsible for forming new memories. This will hopefully revive the area's mitochondria, the energy source in every cell, which become damaged by Alzheimer's.

Evelyn Martin, Research Assistant on the trial explains, "The trial aims to investigate the role of brain activity in the progressive loss of function and structure of brain cells in Alzheimer’s disease using electrical brain stimulation. We have developed approaches to make small, transient alteration to neural activity in brain regions that are affected at the early stages of the disease, non-invasively via temporal interference (TI) deep brain stimulation. The outcome is to measure the changes in the brain's activity, as well as some of its energy sources and cognitive functions."

Participants in the trial

Tests on healthy volunteers show the technique increases blood flow to the brain and results in improved results in facial-recognition tests. This clinical trial, which was completed in December 2023, was the first time that people living with Alzheimer's underwent the treatment.

Eligibility: 24 individuals aged 50-100 years old, with a diagnosis of mild cognitive impairment (MCI) or probable Alzheimer's disease, were recruited to the trial.

Exclusion criteria included but was not limited to: medical, neurological or psychiatric illness that would interfere in completing assessments or impair the safety of the participant for brain stimulation. Other exclusion criteria include: known genetic mutation associated with familial Alzheimer’s disease or any other autosomal dominant form of dementia, any contraindication to MRI.

The study process

Participation in the trial entailed a 3-week commitment, involving:

  • Pre-screening stage: a telephone interview to check eligibility and request access to medical records from GP.
  • Screening visit: blood test, safety questionnaires, clinical interview & examination, Allen's test, ECG, pregnancy test (if applicable) and a trial session with TI to ensure the volunteer is comfortable with the stimulation. This is a single visit which lasts approximately 4 hours and is carried out within 1-2 months before the stimulation and imaging sessions.
  • Ten sessions of up to 60 min of non-invasive brain stimulation separated by 24h (no sessions during weekends).
  • Brain imaging and cognitive assessment sessions before and after the stimulation period, including positron emission tomography (PET), magnetic resonance imaging (MRI) and neurocognitive assessments.

Recruitment for this study has now closed. To learn more about our ongoing trials, visit the Interventional Systems Neuroscience Lab website. To register your interest and discuss participation, please contact Research Assistants Julia Borella ( or Kaarin Šabad (

The team leading the trial

We have a team of amazing experts and researchers working on the project. They are very enthusiastic and excited to work with our volunteers to ensure that they have a pleasant experience and ensure success of the project.

Dr Nir Grossman is a Group Leader at UK DRI at Imperial College London and chief investigator on the project. He developed the TI technology with his collaborators at MIT during his postdoctoral position. He oversees all aspects of the project. ­­­­

Julia Borella, Research Assistant, UK DRI at Imperial College London has extensive experience in delivering electrical brain stimulation. Julia leads the recruitment and screening of volunteers and supports the delivery of the study.

Kaarin Šabad, Research Assistant, UK DRI at Imperial College London completed an MSc in Neuroscience at King's College London, focusing on assessment of memory after neuromodulation. Since then, she has worked as a Cognitive Rehabilitation Assistant for clients with brain injuries. On this project, she leads the TI brain stimulation sessions.

Kety Alania, PhD Student, UK DRI at Imperial College London, has been working with the TI technology for nearly four years and has extensive experience with delivering electrical brain stimulation. On this project, she leads the TI brain stimulation sessions.

Dr Edward Rhodes, Postdoctoral Researcher, UK DRI at Imperial completed his PhD in 2018 during which he applied transcranial electrical/magnetic stimulation in an attempt to mitigate the symptoms of Parkinson's Disease. He has since joined the Interventional Systems Neuroscience lab and the UK Dementia Research Institute where he applies TI and other forms of electrical stimulation to patients with Dementia as well as those with various tremor disorders.

Dr Christopher Butler, Clinical Senior Lecturer in Dementia Research, Imperial College London is a practicing neurologist and lead clinician on project. He oversees participant screening and recruitment and other aspects of the project.

Dr Ines Volante, Senior Lecturer in Psychological Neuroscience, University of Surrey is an expert in variety of brain imaging methods and brain stimulation interventions. She oversees brain imaging and stimulation sessions as well as other parts of the project.