Tag: Brain Stimulation

Breakthrough brain stimulator could revolutionize treatment for neurological disorders

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Rice University engineers have developed the smallest implantable brain stimulator demonstrated in a human patient. Thanks to pioneering magnetoelectric power transfer technology, the pea-sized device developed in the Rice lab of Jacob Robinson in collaboration with Motif Neurotech and clinicians Dr. Sameer Sheth and Dr. Sunil Sheth can be powered wirelessly via an external transmitter and used to stimulate the brain through the dura ⎯ the protective membrane attached to the bottom of the skull.

The device, known as the Digitally programmable Over-brain Therapeutic (DOT), could revolutionize treatment for drug-resistant depression and other psychiatric or neurological disorders by providing a therapeutic alternative that offers greater patient autonomy and accessibility than current neurostimulation-based therapies and is less invasive than other brain-computer interfaces (BCIs).

In this paper we show that our device, the size of a pea, can activate the motor cortex, which results in the patient moving their hand. In the future, we can place the implant above other parts of the brain, like the prefrontal cortex, where we expect to improve executive functioning in people with depression or other disorders.”

Jacob Robinson, professor of electrical and computer engineering and of bioengineering, Rice University

Existing implantable technologies for brain stimulation are powered by relatively large batteries that need to be placed under the skin elsewhere in the body and connected to the stimulating device via long wires. Such design limitations require more surgery and subject the individual to a greater burden of hardware implantation, risks of wire breakage or failure and the need for future battery replacement surgeries.

“We eliminated the need for a battery by wirelessly powering the device using an external transmitter,” explained Joshua Woods, an electrical engineering graduate student in the Robinson lab and lead author on the study published in Science Advances. Amanda Singer, a former graduate student in Rice’s applied physics program who is now at Motif Neurotech, is also a lead author.

The technology relies on a material that converts magnetic fields into electrical pulses. This conversion process is very efficient at small scales and has good misalignment tolerance, meaning it does not require complex or minute maneuvering to activate and control. The device has a width of 9 millimeters and can deliver 14.5 volts of stimulation.

“Our implant gets all of its energy through this magnetoelectric effect,” said Robinson, who is founder and CEO of Motif, a startup working to bring the device to market. “The physics of that power transfer makes this much more efficient than any other wireless power transfer technologies under these conditions.”

Motif is one of several neurotech companies that are probing the potential of BCIs to revolutionize treatments for neurological disorders.

“Neurostimulation is key to enabling therapies in the mental health space where drug side effects and a lack of efficacy leave many people without adequate treatment options,” Robinson said.

The researchers tested the device temporarily in a human patient, using it to stimulate the motor cortex ⎯ the part of the brain responsible for movement ⎯ and generating a hand movement response. They next showed the device interfaces with the brain stably for a 30-day duration in pigs.

“This has not been done before because the quality and strength of the signal needed to stimulate the brain through the dura were previously impossible with wireless power transfer for implants this small,” Woods said.

Robinson envisions the technology being used from the comfort of one’s home. A physician would prescribe the treatment and provide guidelines for using the device, but patients would retain complete control over how the treatment is administered.

“Back home, the patient would put on their hat or wearable to power and communicate with the implant, push ‘go’ on their iPhone or their smartwatch and then the electrical stimulation from that implant would activate a neuronal network inside the brain,” Robinson said.

Implantation would require a minimally invasive 30-minute procedure that would place the device in the bone over the brain. Both the implant and the incision would be virtually invisible, and the patient would go home the same day.

“When you think about a pacemaker, it’s a very routine part of cardiac care,” said Sheth, professor and vice-chair of research, McNair Scholar and Cullen Foundation Endowed Chair of Neurosurgery at the Baylor College of Medicine. “In neurological and psychiatric disorders, the equivalent is deep brain stimulation (DBS), which sounds scary and invasive. DBS is actually quite a safe procedure, but it’s still brain surgery, and its perceived risk will place a very low ceiling on the number of people who are willing to accept it and may benefit from it. Here’s where technologies like this come in. A 30-minute minor procedure that is little more than skin surgery, done in an outpatient surgery center, is much more likely to be tolerated than DBS. So if we can show that it is about as effective as more invasive alternatives, this therapy will likely make a much larger impact on mental health.”

For some conditions, epilepsy for example, the device may need to be on permanently or most of the time, but for disorders such as depression and OCD, a regimen of just a few minutes of stimulation per day could suffice to bring about the desired changes in the functioning of the targeted neuronal network.

In terms of next steps, Robinson said that on the research side he is “really interested in the idea of creating networks of implants and creating implants that can stimulate and record, so that they can provide adaptive personalized therapies based on your own brain signatures.” From the therapeutic development standpoint, Motif Neurotech is in the process of seeking FDA approval for a long-term clinical trial in humans. Patients and caregivers can sign up on the Motif Neurotech website to learn when and where these trials will begin.

The work was supported in part by The Robert and Janice McNair Foundation, the McNair Medical Institute, DARPA and the National Science Foundation.

Source:

Journal reference:

Woods, J. E., et al. (2024) Miniature battery-free epidural cortical stimulators. Science Advances. doi.org/10.1126/sciadv.adn0858.

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April 15, 2024
Non-invasive brain stimulation can change specific brain mechanism linked to human behavior

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For the first time, researchers at the University of Minnesota Twin Cities showed that non-invasive brain stimulation can change a specific brain mechanism that is directly related to human behavior. This is a major step forward for discovering new therapies to treat brain disorders such as schizophrenia, depression, Alzheimer’s disease, and Parkinson’s disease.

The study was recently published in Nature Communications, a peer-reviewed, open access, scientific journal.

Researchers used what is called “transcranial alternating current stimulation” to modulate brain activity. This technique is also known as neuromodulation. By applying a small electrical current to the brain, the timing of when brain cells are active is shifted. This modulation of neural timing is related to neuroplasticity, which is a change in the connections between brain cells that is needed for human behavior, learning, and cognition.

Previous research showed that brain activity was time-locked to stimulation. What we found in this new study is that this relationship slowly changed and the brain adapted over time as we added in external stimulation. This showed brain activity shifting in a way we didn’t expect.”

Alexander Opitz, Associate Professor, Department of Biomedical Engineering, University of Minnesota

This result is called “neural phase precession.” This is when the brain activity gradually changes over time in relation to a repeating pattern, like an external event or in this case non-invasive stimulation. In this research, all three investigated methods (computational models, humans, and animals) showed that the external stimulation could shift brain activity over time.

“The timing of this repeating pattern has a direct impact on brain processes, for example, how we navigate space, learn, and remember,” Opitz said.

The discovery of this new technique shows how the brain adapts to external stimulation. This technique can increase or decrease brain activity, but is most powerful when it targets specific brain functions that affect behaviors. This way, long-term memory as well as learning can be improved. The long-term goal is to use this technique in the treatment of psychiatric and neurological disorders.

Opitz hopes that this discovery will help bring improved knowledge and technology to clinical applications, which could lead to more personalized therapies for schizophrenia, depression, Alzheimer’s disease, and Parkinson’s disease.

In addition to Opitz, the research team included co-first authors Miles Wischnewski and Harry Tran. Other team members from the University of Minnesota Biomedical Engineering Department include Zhihe Zhao, Zachary Haigh, Nipun Perera, Ivan Alekseichuk, Sina Shirinpour and Jonna Rotteveel. This study was in collaboration with Dr. Jan Zimmermann, associate professor in the University of Minnesota Medical School.

This work was supported primarily by the National Institute of Health (NIH) along with the Behavior and Brain Research Foundation and the University of Minnesota’s Minnesota’s Discovery, Research, and InnoVation Economy (MnDRIVE) Initiative. Computational resources were provided by the Minnesota Supercomputing Institute (MSI).

Source:

Journal reference:

Wischnewski, M., et al. (2024). Induced neural phase precession through exogenous electric fields. Nature Communications. doi.org/10.1038/s41467-024-45898-5.

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March 15, 2024
Study unveils role of dopamine and serotonin in social behavior

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In a study in today’s (Monday Feb. 26) Nature Human Behavior, scientists delve into the world of chemical neuromodulators in the human brain, specifically dopamine and serotonin, to reveal their role in social behavior.

The research, conducted in Parkinson’s disease patients undergoing brain surgery while awake, homed in on the brain’s substantia nigra, a crucial area associated with motor control and reward processing.

Led by Virginia Tech computational neuroscientist Read Montague, the international team revealed a previously unknown neurochemical mechanism for a well-known human tendency to make decisions based on social context -; people are more likely to accept offers from computers while rejecting identical offers from human players.

Insight from an ultimatum game

In the study, four patients receiving deep brain stimulation surgery for Parkinson’s disease were immersed in the “take it or leave it” ultimatum game, a scenario where they had to accept or reject varying splits of $20 from both human and computer players. For instance, one player may propose to keep $16, whereas the patient gets the remaining $4. If the patient rejects the split, then neither of them receives anything.

You can teach people what they should do in these kinds of games -; they should accept even small rewards as opposed to no reward at all. When people know they’re playing a computer, they play perfectly, just like mathematical economists – they do what they should do. But when they’re playing a human being, they cannot help themselves. They are often driven to punish the smaller bid by rejecting it.”

Read Montague, Montague, the Virginia Tech Carilion Mountcastle professor, Fralin Biomedical Research Institute at VTC and senior author of the study

Dopamine-serotonin dance

The idea that people make decisions based on social context is not a new one in neural economic games. But now, for the first time, researchers show the impact of the social context may spring from the dynamic interactions of dopamine and serotonin.

When people make decisions, dopamine seems to closely follow and react to whether the current offer is better or worse than the previous one, as if it were a continuous tracking system. Serotonin, meanwhile, appears to focus only on the current value of the specific offer at hand, suggesting a more case-by-case evaluation.

This fast dance happens against a slower backdrop, where dopamine is overall higher when people play other human beings – in other words, when fairness comes into play. Together, these signals contribute to our brain’s overall assessment of value during social interactions.

“We are shining a spotlight on various cognitive processes and finally receiving answers to questions in finer biological detail,” said study shared first author Dan Bang, associate professor of clinical medicine and Lundbeck Foundation Fellow at Aarhus University in Denmark, and an adjunct associate professor at the Fralin Biomedical Research Institute.

“Dopamine levels are higher when people interact with another human as opposed to a computer,” Bang said. “And here it was important that we also measured serotonin to give us confidence that the overall response to social context is specific to dopamine.”

Seth Batten, a senior research associate in Montague’s lab and shared first author of the study, built the carbon-fiber electrodes that were implanted in patients receiving Deep Brain Stimulation surgery and helped collect the data at the Mount Sinai Health System in New York.

“The unique twist with our method is that it allows us to measure more than one neurotransmitter at a time -; the impact of that should not be lost,” Batten said. “We’ve seen these signaling molecules before, but this is the first time we’ve seen them dance. No one has ever seen this dance of dopamine and serotonin in a social context before.”

Teasing out the meaning of the electrochemical signals recorded from patients in surgery was a major challenge that took years to solve.

“The raw data that we’re collecting from patients isn’t specific to dopamine, serotonin, or norepinephrine – it’s a mixture of those,” said Ken Kishida, a co-author of the study and an associate professor of translational neuroscience, and neurosurgery, at Wake Forest University School of Medicine. “We’re essentially using machine-learning type tools to separate what’s in the raw data, understand the signature, and decode what’s going on with dopamine and serotonin.”

In the Nature Human Behavior study, researchers showed how the rise and fall of dopamine and serotonin are intertwined with human cognition and behavior.

“In the model organism world, there is a candy store full of fantastical techniques to ask biological questions, but it’s harder to ask questions about what makes you, you,” said Montague, who is also the director of the Center for Human Neuroscience Research and the Human Neuroimaging Laboratory of the Fralin Biomedical Research Institute.

Addressing Parkinson’s

“At some point, after we have evaluated enough people, we’re going to be able to address the Parkinson’s disease pathology that’s given us this window of opportunity,” said Montague, who is also a professor in the Virginia Tech College of Science.

In Parkinson’s disease, a significant loss of dopamine-producing neurons in the brainstem is a key characteristic that usually coincides with the onset of symptoms.

This loss impacts the striatum, a brain region heavily influenced by dopamine. As dopamine diminishes, serotonin terminals begin to sprout, revealing a complex interaction, as observed in rodent models.

“Already there is pre-clinical evidence that the attrition of the dopamine system is telling the serotonin system, ‘Hey, we’ve got to do something.’ But we’ve never been able to watch the dynamics,” Montague said. “What we’re doing now is the first step, but one would hope that once we get up to hundreds of patients, we’d be able to relate this to symptomatology and make some clinical statements about the Parkinson’s pathology.”

In that respect, researchers said a window is opening to learn about a wide range of brain disorders.

“The human brain is like a black box,” Kishida said. “We have developed one more way to look inside and understand how these systems work and how they have become affected by various clinical conditions.”

Michael Friedlander, executive director of the Fralin Biomedical Research Institute and a neuroscientist who was not involved in the study, said, “This work is changing the entire field of neuroscience and our ability to query the human mind and brain -; with a technology that was just not even imagined not many years ago.”

Psychiatry is an example of a medical field that could benefit by this approach, he said.

“We have an enormous number of people in the world who suffer from a variety of psychiatric conditions, and, in many cases, the pharmacological solutions do not work very well,” said Friedlander, who is also Virginia Tech’s vice president of health sciences and technology. “Dopamine, serotonin, and other neurotransmitters are in some ways intimately involved with those disorders. This effort adds real precision and quantitation to understand those problems. The one thing I think we can be sure of is this work is going to be extremely important in the future for developing treatments.”

More than a decade in the making

The effort to measure neurotransmitters in real-time in the human brain began more than 12 years ago when Montague assembled a team of experts who “think about thinking, a lot.”

In first-of-their-kind observations in the human brain the scientists published in Neuron in 2020, researchers revealed dopamine and serotonin are at work at sub-second speeds to shape how people perceive the world and take action based on their perception.

More recently, in a study published in October in the journal Current Biology, the researchers used their method of recording chemical changes in awake humans to gain insight into the brain’s noradrenaline system, which has been a longtime target for medications to treat psychiatric disorders.

And, in December in the journal Science Advances, the team revealed that fast changes in dopamine levels reflect a specific computation related to how humans learn from rewards and punishments.

“We’ve made active measurements of neurotransmitters multiple times in different brain regions, and we have now reached the point where we’re touching on crucial elements of what makes us human beings,” Montague said.

Source:

Journal reference:

Batten, S. R., et al. (2024). Dopamine and serotonin in human substantia nigra track social context and value signals during economic exchange. Nature Human Behaviour. doi.org/10.1038/s41562-024-01831-w.

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February 26, 2024
Novel technique could transform the treatment landscape for brain disorders

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The human brain’s adaptability to internal and external changes, known as neural plasticity, forms the foundation for understanding cognitive functions like memory and learning, as well as various neurological disorders. New research conducted by a team led by Dr. PARK Joo Min of the Center for Cognition and Sociality within the Institute for Basic Science (IBS) unveils a novel technique that could transform the treatment landscape for brain disorders. The team developed a non-invasive brain stimulation method called Patterned Low-Intensity Low-Frequency Ultrasound (LILFUS), which holds tremendous potential for inducing long-lasting changes in brain function.

Traditionally, magnetic and electrical brain stimulation methods have been used to modulate brain function. However, these methods come with inherent limitations that restrict their spatial resolution and penetration depth, making it challenging to precisely stimulate specific brain regions with optimal efficacy. More invasive methods, such as those that require surgical procedures, exhibit superior control and therapeutic effects for specific deep brain stimulation, but they come with risks such as tissue damage, inflammation, and infection. These limitations have fueled the search for alternative approaches that can overcome these constraints and provide more efficient and precise modulation of brain function.

In the latest study unveiled by the IBS, researchers used ultrasound to enable precise stimulation of specific brain areas. Unlike electromagnetic waves, ultrasound has the advantage of being able to penetrate deep into the brain tissues. The researchers discovered that ultrasound stimulation can modulate neural plasticity – the brain’s ability to rewire itself – through the activation of key molecular pathways. Specifically, the study pinpointed the ultrasound’s effect on mechanosensitive calcium channels in astrocytes, which controls the cells’ ability to uptake calcium and release neurotransmitters.

LILFUS was designed based on specific ultrasound parameters that mimic the brainwave patterns of theta (5 Hz) and gamma (30 Hz) oscillations observed during learning and memory processes. The new tool allowed the researchers to either activate or deactivate specific brain regions at will – intermittent delivery of the ultrasound was found to induce long-term potentiation effects, while continuous patterns resulted in long-term depression effects.

One of the most promising aspects of this new technology is its ability to facilitate the acquisition of new motor skills. When the researchers delivered ultrasound stimulation to the cerebral motor cortex in mice, they observed significant improvements in motor skill learning and the ability to retrieve food. Interestingly, researchers were even able to change the forelimb preference of the mice. This suggests potential applications in rehabilitation therapies for stroke survivors and individuals with motor impairments.

The implications of this research extend far beyond motor function. It may be used to treat conditions such as depression, where altered brain excitability and plasticity are prominent features. With further exploration, LILFUS could be adapted for various brain stimulation protocols, offering hope for various conditions ranging from sensory impairments to cognitive disorders.

This study has not only developed a new and safe neural regulation technology with long-lasting effects but has also uncovered the molecular mechanism changes involved in brainwave-patterned ultrasound neural regulation. We plan to continue follow-up studies to apply this technology for the treatment of brain disorders related to abnormal brain excitation and inhibition and for the enhancement of cognitive functions.”

Dr. Park Joo Min of the Center for Cognition and Sociality, Institute for Basic Science

Source:

Institute for Basic Science

Journal reference:

Kim, H-J., et al. (2024) Long-lasting forms of plasticity through patterned ultrasound-induced brainwave entrainment. Science Advances. doi.org/10.1126/sciadv.adk3198.

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February 24, 2024
Using deep brain stimulation to map dysfunctional brain circuits linked to four disorders

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Mass General Brigham researchers identified sets of connections that are disrupted and malfunctioning as a consequence of Parkinson’s disease, dystonia, obsessive compulsive disorder and Tourette’s syndrome.

Fiber bundles associated with symptom improvement following deep brain stimulation in Parkinson’s disease (green), dystonia (yellow), Tourette’s syndrome (blue),and obsessive-compulsive disorder (red). Image Credit: Barbara Hollunder

A new study led by investigators from Mass General Brigham demonstrated the use of deep brain stimulation (DBS) to map a ‘human dysfunctome’ — a collection of dysfunctional brain circuits associated with different disorders. The team identified optimal networks to target in the frontal cortex that could be used for treating Parkinson’s disease, dystonia, obsessive compulsive disorder (OCD) and Tourette’s syndrome. Their results are published in Nature Neuroscience.

“We were able to use brain stimulation to precisely identify and target circuits for the optimal treatment of four different disorders,” said co-corresponding author Andreas Horn, MD, PhD, of the Center for Brain Circuit Therapeutics in the Department of Neurology at Brigham and Women’s Hospital and the Center for Neurotechnology and Neurorecovery at Massachusetts General Hospital. “In simplified terms, when brain circuits become dysfunctional, they may act as brakes for the specific brain functions that the circuit usually carries out. Applying DBS may release the brake and may in part restore functionality.”

Connections between the frontal cortex in the forebrain and basal ganglia, structures located deeper in the brain, are known to control cognitive and motor functions. If brain disorders occur, these circuits may become affected, and their communication may become overactive or malfunction. Previous studies have shown that electrically stimulating the subthalamic nucleus, a small region in the basal ganglia that receives inputs from the entire frontal cortex, can help alleviate symptoms of these disorders.

To understand this relationship better, the authors analyzed data from 534 DBS electrodes in 261 patients from across the globe. Of this cohort, 70 patients were diagnosed with dystonia, 127 with Parkinson’s disease, 50 with OCD and 14 with Tourette’s syndrome. Using software developed by Horn’s team, the researchers mapped the precise location of each electrode and registered results to a common reference atlas to compare locations across patients. The researchers used computer simulations to map tracts that were activated in patients with optimal or suboptimal outcomes.

Using these results, they were able to identify specific brain circuits that had become dysfunctional in each of the four disorders, such as those mapping to sensorimotor cortices in dystonia, the primary motor cortex in Tourette’s, the supplementary motor cortex in Parkinson’s disease and parts of the cingulate cortex in OCD. Notably, the identified circuits partially overlapped, implying that interconnected pathways are disrupted in these disorders.

Further, the investigators were able to apply these findings to fine tune DBS treatments and demonstrate preliminary improved results in three cases, including one at Massachusetts General Hospital, a founding member of Mass General Brigham. This patient, a female in her early 20s, was diagnosed with severe, treatment-resistant OCD involving obsessions about food and water intake, along with compulsive skin picking. Following electrode implantation and targeted stimulation, the researchers were able to show a significant improvement in her symptoms one month after treatment.

Except for the three patients that were tested prospectively, the study was a retrospective analysis of data aggregated from multiple centers. Further studies are needed to validate findings in prospective fashion.

We can take this technique further and finely segregate dysfunctional circuits in order to have greater impact with treatment. For example, with OCD, we can look at isolating circuits for obsessions versus compulsions and so on.”

Barbara Hollunder, MSc, Lead Author, Movement Disorders and Neuromodulation Unit, Department of Neurology, Charité – University Medicine Berlin

Source:

Journal reference:

Hollunder, B., et al. (2024) Mapping Dysfunctional Circuits in the Frontal Cortex Using Deep Brain Stimulation. Nature Neuroscience. doi.org/10.1038/s41593-024-01570-1.

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February 24, 2024
Mapping the human dysfunctome with deep brain stimulation

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A new study led by investigators from Mass General Brigham demonstrated the use of deep brain stimulation (DBS) to map a ‘human dysfunctome’ -; a collection of dysfunctional brain circuits associated with different disorders. The team identified optimal networks to target in the frontal cortex that could be used for treating Parkinson’s disease, dystonia, obsessive compulsive disorder (OCD) and Tourette’s syndrome. Their results are published in Nature Neuroscience.

“We were able to use brain stimulation to precisely identify and target circuits for the optimal treatment of four different disorders,” said co-corresponding author Andreas Horn, MD, PhD, of the Center for Brain Circuit Therapeutics in the Department of Neurology at Brigham and Women’s Hospital and the Center for Neurotechnology and Neurorecovery at Massachusetts General Hospital. “In simplified terms, when brain circuits become dysfunctional, they may act as brakes for the specific brain functions that the circuit usually carries out. Applying DBS may release the brake and may in part restore functionality.”

Connections between the frontal cortex in the forebrain and basal ganglia, structures located deeper in the brain, are known to control cognitive and motor functions. If brain disorders occur, these circuits may become affected, and their communication may become overactive or malfunction. Previous studies have shown that electrically stimulating the subthalamic nucleus, a small region in the basal ganglia that receives inputs from the entire frontal cortex, can help alleviate symptoms of these disorders.

To understand this relationship better, the authors analyzed data from 534 DBS electrodes in 261 patients from across the globe. Of this cohort, 70 patients were diagnosed with dystonia, 127 with Parkinson’s disease, 50 with OCD and 14 with Tourette’s syndrome. Using software developed by Horn’s team, the researchers mapped the precise location of each electrode and registered results to a common reference atlas to compare locations across patients. The researchers used computer simulations to map tracts that were activated in patients with optimal or suboptimal outcomes.

Using these results, they were able to identify specific brain circuits that had become dysfunctional in each of the four disorders, such as those mapping to sensorimotor cortices in dystonia, the primary motor cortex in Tourette’s, the supplementary motor cortex in Parkinson’s disease and parts of the cingulate cortex in OCD. Notably, the identified circuits partially overlapped, implying that interconnected pathways are disrupted in these disorders.

Further, the investigators were able to apply these findings to fine tune DBS treatments and demonstrate preliminary improved results in three cases, including one at Massachusetts General Hospital, a founding member of Mass General Brigham. This patient, a female in her early 20s, was diagnosed with severe, treatment-resistant OCD involving obsessions about food and water intake, along with compulsive skin picking. Following electrode implantation and targeted stimulation, the researchers were able to show a significant improvement in her symptoms one month after treatment.

Except for the three patients that were tested prospectively, the study was a retrospective analysis of data aggregated from multiple centers. Further studies are needed to validate findings in prospective fashion.

We can take this technique further and finely segregate dysfunctional circuits in order to have greater impact with treatment. For example, with OCD, we can look at isolating circuits for obsessions versus compulsions and so on.”

Barbara Hollunder, MSc, lead author of the Movement Disorders and Neuromodulation Unit in the Department of Neurology, Charité – University Medicine Berlin

Source:

Journal reference:

Hollunder, B., et al. (2024) Mapping Dysfunctional Circuits in the Frontal Cortex Using Deep Brain Stimulation. Nature Neuroscience. doi.org/10.1038/s41593-024-01570-1.

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February 23, 2024
ASU professor offers insights on what may be coming from Neuralink’s PRIME study

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This week, Neuralink’s Elon Musk announced that human clinical trials have begun on its Precise Robotically Implanted Brain-Computer Interface (PRIME) study, a medical device trail that uses wireless, brain-computer interface designed to enable people with paralysis to control external devices with their thoughts.

According to Arizona State University’s Bradley Greger, an associate professor of neural engineering who first addressed the plausibility of Neuralink’s technology in late 2022, “This technology is going to be such a gamechanger.”

Greger has worked on restoring vision and speech using brain-computer interfaces, and is currently investigating how deep brain stimulation (DBS) treats patients with movement and pain disorders.

“We are using DBS technology to record signals from the human brain, but we only have several channels,” said Greger. “Neuralink is using different technology to record from what is equivalent to thousands of channels.”

As a neural engineer, Professor Greger offers his insights on what may be coming from Neuralink’s PRIME study.

Question: How accessible will this technology be to other researchers?

Answer: That’s going to be up to Neuralink. Every researcher I’ve ever talked with about Neuralink has asked the same question: “When are we going to be able to get our hands on it?”

Q: Is Neuralink currently partnering with a research hospital?

A: They definitely have partnered with a major neuro-surgical center somewhere in America with this first patient study. Nobody knows which one – they don’t want media hounding the hospital, the family and most importantly, the patient.

Q: Do you think Neuralink will soon partner with additional neurological research institutions?

A: Oh, absolutely – with multiple medical centers. I suspect that conversations and visits have been underway for a while. But potential partners are totally locked down by nondisclosure agreements as a precursor to research relationships.

The criteria for partnership will be finding qualifying patients, but also institutions with the surgical skill and support infrastructure. There are not a lot of places that meet that criteria.

If I were making the rounds for Neuralink, I’d be talking to the folks at Stanford, UC San Francisco and Massachusetts General – the places that have the neurosurgical expertise and have a proven track record of performing well in this type of research.

Q: Will each of the partnering institutions have to go through the FDA approval process?

A: Probably not. The technology and procedures are already FDA approved. The partners will go through an institutional review board (IRB) process at their institutions – every major hospital has its own IRB.

Q: Will the initial study focus exclusively on paralysis patients?

A: Yes. I think the research partnerships they will take on first will focus on restoring movement for those with paralysis – patients that have amyotrophic lateral sclerosis (ALS) or severe spinal cord lesions.

Control of movement is one of the things we understand most about the brain, so I’d say it’s the easiest target to begin with.

I haven’t seen the actual protocol, but for this type of study you would typically want to work with about 10 or so patients.

Q: How long do you think it will be before they expand the trial?

A: This phase of the study will probably go about a year or two.

If it all goes well and the devices are working as anticipated, and the patients are healthy beyond their paralysis issues, Neuralink may then move beyond feasibility trials into testing safety and efficacy. For instance, they might have a patients try to control robotic arms with their minds. With Neuralink’s technology, I think you could see that as soon as one year from now, or at the outside, two or three years.

In the approval process for the FDA, they have to specify the type of patients they will work with.

Q: If and when Neuralink moves beyond paralysis studies, will they have to go through the FDA approval process again for a speech restoration study?

A: They will certainly need additional IRB approvals. FDA approvals revolve around the device. If they move to a speech restoration study, for example, researchers may have to get an investigational device exemption (IDE), but that’s much more simple process than establishing the safety of the device itself.

For a vision restoration trial, they likely will have to go back to the FDA for another approval because that involves stimulation of the brain, which is quite different than this study. They probably have been working on a vision protocol in the background for years.

Although vision restoration will use the same technology, the same wiring and the same device, it will be implanted in in a different location and will involve electricity going into the brain rather than out of the brain. That’s what may make it different from the FDA’s perspective.

Q: How long do you think it will take before Neuralink’s technology is actually available to the general public?

A: The technology may be generally available with a physician’s or surgeon’s prescription in several years. Therefore, most initial users will be patients with neurological disorders. I am somewhat skeptical that healthy people will undergo neurosurgery to get the device or that the surgery would be allowed without some medical condition to be treated by the device.

Source:

Arizona State University (ASU)

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February 3, 2024
Nerve stimulation plus physical rehabilitation may boost recovery of arm and hand function
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Combining brain stimulation with intense physical rehabilitation helped stroke survivors recover movement in their arms and hands and maintain these improvements for one year, according to a study to be presented at the American Stroke Association’s International Stroke Conference 2024. The meeting will be held in Phoenix, Feb. 7-9, and is a world premier meeting for researchers and clinicians dedicated to the science of stroke and brain health.

The recovery of arm and hand function after a stroke often stalls or even declines, leaving many patients with chronic motor deficits that limit their independence and quality of life. New treatments that can boost the benefits of physical rehabilitation are desperately needed.”

Teresa J. Kimberley, Ph.D., study’s lead author, professor of rehabilitation science and physical therapy at MGH Institute of Health Professions in Boston

Vagus nerve stimulation is the first approved neuromodulation device to aid in chronic stroke recovery. It was approved by the U.S. Food and Drug Administration in 2021 to treat moderate to severe upper extremity motor function deficits (physical movement and coordination of arms and hands) associated with chronic stroke.

“This is the first time that brain stimulation combined with rehabilitation therapy for stroke is available outside of a clinical trial. It could set the stage for even more advancements in recovery from other impairments beyond the arm,” Kimberley said. “This is a watershed moment for rehabilitation science.”

This study represents one-year outcomes in the VNS-REHAB pivotal trial, which studied people who had a stroke resulting in moderate to severe upper extremity impairment.

Two groups of participants (108 total people) -; a control group and an experimental group -; completed six weeks of in-clinic, intense rehabilitation paired with active or sham vagus nerve stimulation. All participants were implanted with the nerve stimulation device and then randomized to receive either real nerve stimulation or a sham stimulation that only turned on for a few pulses. The in-clinic therapy was followed by a three-month home exercise program for both groups. The active vagus nerve stimulation group continued the home exercise program for a year. After the six-week period of sham stimulation, the control group crossed over and received six weeks of active vagus nerve stimulation followed by a year of the home exercise program.

Before and after the stimulation and rehabilitation therapies, motor function was assessed with the Fugl-Meyer Assessment-Upper Extremity, which assesses motor impairment, and the Wolf Motor Function Test, which is a time-based method to evaluate upper extremity motor ability while providing a better understanding of joint-specific and total limb movements.

The final study results represent outcomes for arm and hand function in 74 stroke survivors after one year of physical rehabilitation treatment. Data was unavailable for the remaining 34 participants mainly due to the COVID-19 pandemic.

This analysis found:
- At one-year, upper limb function improved by 5.3 points in the Fugl-Meyer Assessment-Upper Extremity and by 0.51 points in the Wolf Motor Function Test when compared to baseline.
- Vagus nerve stimulation therapy improved hand and arm function by 2-3 times more than intense rehabilitation alone.
“The pairing of rehabilitation therapy with vagus nerve stimulation likely helps the brain strengthen new neural pathways – like building a bridge to bypass a damaged area,” Kimberley said.

“These long-term, pivotal results mirror our long-term results from an earlier pilot study where we found that patients continue to improve or maintain their gains up to three years after starting vagus nerve stimulation therapy paired with rehabilitation,” she said. “As a clinician, it is surprising to see someone with chronic stroke – stroke that in many ways is a progressive disease – continue to improve and not show a decline.”

Study details and background:
- The vagus nerve stimulation device in this study included a pacemaker connected to a lead that wraps around the vagus nerve in the neck region. There’s one vagus nerve on each side of the body; each one runs from the lower part of the brain through the neck to the chest and stomach.
- VNS-REHAB trial participants were between the ages of 22-80 and had a stroke nine months to 10 years prior to study enrollment.
- Study participants in the experimental group were 64% male and 36% female; 79% white, 17% African American adults, 2% Asian, Indian or other adults, and 1% did not have any race reported. The control group was 65% male and 35% female; 78% white, 16% African American adults, 7% Asian, Indian or other adults, and 1% did not have any race reported.
- The study took five years to complete: 2017-2019 for enrollment, and the study ended in 2021.
- The study was triple-blinded, meaning neither the participants, the researchers testing participants nor the health care professionals treating participants knew which intervention group participants were in.
Study limitations included the small sample size and lack of details about the rehabilitation therapy regimens followed by each participant over the one-year period, which were variable.

Future studies and an ongoing clinical registry will explore the long-term impact of active vagus nerve stimulation in real-world settings.

“Often after a stroke, people don’t seek additional treatment, thinking that their current impairments are permanent. This is not true! Paired vagus nerve stimulation opens a new avenue and new hope for these patients. I’m also excited about future research that will investigate vagus nerve stimulation paired with rehabilitation for other conditions, such as gait and speech impairments after stroke,” Kimberley said.

“These are encouraging findings,” said Joel Stein, M.D., FAHA, chair of the writing group for the American Heart Association’s/American Stroke Association’s 2021 Clinical Performance Measures for Stroke Rehabilitation and the Simon Baruch Professor and chair of the department of rehabilitation and regenerative medicine at Columbia University’s Vagelos College of Physicians and Surgeons; professor and chair of the department of rehabilitation medicine at Weill Cornell Medicine; and physiatrist-in-chief at NewYork-Presbyterian Hospital. “These results demonstrate the durability of the effects of vagus nerve stimulation, an important finding that supports the use of this modality to enhance recovery post-stroke. There is some evidence for lasting improvement with continued use outside of a formal exercise program, which is intriguing, although further research is needed to confirm this finding and clarify who is likely to experience ongoing improvements.” Dr. Stein was not involved in this study.

Source:

American Heart Association
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February 1, 2024