Posts Tagged brain implant

[NEWS] Brain-zapping implants that fight depression inch closer to reality | Science News

Researchers are resetting the part of the brain that can shift mood

BY LAURA SANDERS, FEBRUARY 10, 2019
neural activity

MOOD CHANGER  Neural activity in certain areas of the brain (brightly colored strands show connections emanating from those regions) can be measured to decode mood.

Like seismic sensors planted in quiet ground, hundreds of tiny electrodes rested in the outer layer of the 44-year-old woman’s brain. These sensors, each slightly larger than a sesame seed, had been implanted under her skull to listen for the first rumblings of epileptic seizures.

The electrodes gave researchers unprecedented access to the patient’s brain. With the woman’s permission, scientists at the University of California, San Francisco began using those electrodes to do more than listen; they kicked off tiny electrical earthquakes at different spots in her brain.

Most of the electrical pulses went completely unnoticed by the patient. But researchers finally got the effect they were hunting for by targeting the brain area just behind her eyes. Asked how she felt, the woman answered: “Calmer in my nerves.”

Zapping the same spot in other participants’ brains evoked similar responses: “I feel positive, relaxed,” said a 53-year-old woman. A 60-year-old man described “starting to feel a little more alive, a little more energy.” With stimulation to that one part of the brain, “participants would sit up a little straighter and seem a little bit more alert,” says UCSF neuroscientist Kristin Sellers.

Such positive mood changes in response to light neural jolts, described in the Dec. 17 Current Biology, bring researchers closer to an audacious goal: a device implanted into the brains of severely depressed people to detect a looming crisis coming on and zap the brain out of it.

It sounds farfetched, and it is. The project is “fundamental, pioneering, discovery neuroscience,” says Mark George, a psychiatrist and neurologist at the Medical University of South Carolina in Charleston. George has been studying depression for 30 years. “It’s like sending a spacecraft to the moon.”

This video shows the location of brain regions involved in emotion processing: the orbitofrontal cortex (green), cingulate (red), insula (purple), hippocampus (yellow) and amygdala (blue). The dots show where electrodes were placed to monitor seizures in patients with epilepsy.

Still, in the last several years, teams of scientists have made startling amounts of progress, both in their ability to spot the neural signatures that come with a low mood and to change a person’s feelings.

With powerful computational methods, scientists have recently zeroed in on some key features of depressed brains. Those hallmarks include certain types of brain waves in specific locations, like the one just behind and slightly above the eyes. Other researchers are focused on how to correct the faulty brain activity that underlies depression.

A small, implantable device capable of both learning the brain’s language and then tweaking the script when the story gets dark would be an immensely important clinical tool. Of the 16.2 million U.S. adults with severe depression, about a third don’t respond to conventional treatments. “That’s a huge number of people with a very disabling and probably underdiagnosed and underappreciated illness,” says neurologist Vikram Rao, who is working on the UCSF project with Sellers.

A disease of circuits

When George began studying depression decades ago, the field was still haunted by Sigmund Freud, who blamed the disorder on bad parenting and repressed anger. Soon after came the chemical imbalance concept, which held that the brain just needs a dash of the right chemical signal to fix itself. “It was the ‘brain is soup’ model,” George says. Toss in more of the crucial ingredient — serotonin, for instance — and the recipe would sing.

“We have a very different view now,” George says. Thanks to advances in brain imaging, scientists see depression as a disorder of neural circuits — altered connections between important brain regions can tip a person into a depressed state. “We’ve started to define the road map of depression,” George says.

Depression is a disorder, but one that’s tightly linked to emotion. It turns out that emotions span much of the brain. “Emotions are more widespread than we thought,” says cognitive neuroscientist Kevin LaBar. With his colleagues at Duke University, LaBar has used functional MRI scans to find signatures of certain emotions throughout the brain as people are feeling those emotions. He found the wide neural reach of sorrow, for instance, by prompting the emotion with gloomy songs and films.

Some electrical arrays that researchers at the University of California, San Francisco are testing sit on the surface of the brain (top); others penetrate deep into brain tissue (bottom).

Functional MRI allows scientists to see the entire scope of a working brain, but that wide view comes with the trade-off of lower resolution. And resolution is what’s needed to precisely and quickly sense — and change — brain activity. Implanting electrodes, like those used in the UCSF project, gives a more nuanced look into select brain areas. Those detailed recordings, taken from people undergoing epilepsy treatment, are what allowed neural engineer Maryam Shanechi to decode the brain’s emotions with precision.

As seven patients spent time in the hospital with electrodes monitoring brain activity, their emotions naturally changed. Every so often, the participants would answer mood-related questions on a tablet computer so that researchers could measure when the patients shifted between emotions. Then Shanechi, of the University of Southern California in Los Angeles, and her colleagues matched the brain activity data to the moods.

The task wasn’t simple. The implanted electrodes recorded an enormous pile of data, much of it irrelevant to mood. Shanechi and her team developed an algorithm to distill all that data into a few key predictive brain regions for each person. The resulting decoder could tell what mood a person was in based on brain activity alone, the team reported in the October Nature Biotechnology. “In every single individual, we can show how their mood changes in real time,” Shanechi says.[…]

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[WEB SITE] Electrically stimulating the brain may restore movement after stroke

June 18, 2018, University of California, San Francisco
stroke

Micrograph showing cortical pseudolaminar necrosis, a finding seen in strokes on medical imaging and at autopsy. H&E-LFB stain. Credit: Nephron/Wikipedia

UC San Francisco scientists have improved mobility in rats that had experienced debilitating strokes by using electrical stimulation to restore a distinctive pattern of brain cell activity associated with efficient movement. The researchers say they plan to use the new findings to help develop brain implants that might one day restore motor function in human stroke patients.

After a , roughly one-third of  recover fully, one-third have significant lingering  problems, and one-third remain virtually paralyzed, said senior author Karunesh Ganguly, MD, Ph.D., associate professor of neurology and a member of the UCSF Weill Institute for Neurosciences. Even patients who experience partial recovery often continue to struggle with “goal-directed” movements of the arms and hands, such as reaching and manipulating objects, which can be crucial in the workplace and in daily living.

“Our main impetus was to understand how we can develop implantable neurotechnology to help stroke patients,” said Ganguly, who conducts research at the San Francisco VA Health Care System. “There’s an enormous field growing around the idea of neural implants that can help neural circuits recover and improve function. We were interested in trying to understand the circuit properties of an injured brain relative to a healthy brain and to use this information to tailor neural implants to improve  after stroke.”

Over the past 20 years, neuroscientists have presented evidence that coordinated patterns of neural activity known as oscillations are important for efficient brain function. More recently, low-frequency oscillations (LFOs)—which were first identified in studies of sleep—have been specifically found to help organize the firing of neurons in the brain’s primary motor cortex. The motor cortex controls voluntary movement, and LFOs chunk the cells’ activity together to ensure that goal-directed movements are smooth and efficient.

In the new study, published in the June 18, 2018 issue of Nature Medicine, the researchers first measured neural activity in rats while the animals reached out to grab a small food pellet, a task designed to emulate human goal-directed movements. They detected LFOs immediately before and during the action, which inspired the researchers to investigate how these activity patterns might change after stroke and during recovery.

To explore these questions, they caused a stroke in the rats that impaired the animals’ movement ability, and found that LFOs diminished. In rats that were able to recover, gradually making faster and more precise movements, the LFOs also returned. There was a strong correlation between recovery of function and the reemergence of LFOs. Animals that fully recovered had stronger low-frequency activity than those that partially recovered, and those that didn’t recover had virtually no low-frequency activity.

To try to boost recovery, the researchers used electrodes to both record activity and deliver a mild electrical current to the rats’ brains, stimulating the area immediately surrounding the center of the . This stimulation consistently enhanced LFOs in the damaged area and appeared to improve motor function: when the researchers delivered a burst of electricity right before a rat made a movement, the rat was up to 60 percent more accurate at reaching and grasping for a food pellet.

“Interestingly, we observed this augmentation of LFOs only on the trials where stimulation was applied,” said Tanuj Gulati, Ph.D., a postdoctoral researcher in the Ganguly lab who is co-first author of the study, along with Dhakshin Ramanathan, MD, Ph.D., now assistant professor of psychiatry at UC San Diego, and Ling Guo, a neuroscience graduate student at UCSF.

“We are not creating a new frequency, we are amplifying the existing frequency,” added Ganguly. “By amplifying the weak low-frequency oscillations, we are able to help organize the task-related . When we delivered the electrical current in step with their intended actions, motor control actually got better.”

The researchers wanted to know whether their findings might also apply to humans, so they analyzed recordings made from the surface of the brain of an epilepsy patient who had suffered a stroke that had impaired the patient’s arm and hand movements. The recordings revealed significantly fewer LFOs than recordings made in two epilepsy patients who hadn’t had a stroke. These findings suggest that, just as in rats, the stroke had caused a loss of low-frequency  that impaired the patient’s movement.

Physical therapy is the only treatment currently available to aid stroke patients in their recovery. It can help people who are able to recover neurologically get back to being fully functional more quickly, but not those whose stroke damage is too extensive. Ganguly hopes that electrical brain stimulation can offer a much-needed alternative for these latter patients, helping their brain circuits to gain better control of motor neurons that are still functional. Electrical  stimulation is already widely used to help patients with Parkinson’s disease and epilepsy, and Ganguly believes stroke patients may be the next to benefit.

 Explore further: Electrical nerve stimulation could help patients regain motor functions sooner

More information: Low-frequency cortical activity is a neuromodulatory target that tracks recovery after stroke, Nature Medicine (2018). www.nature.com/articles/s41591-018-0058-y

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[WEB SITE] Electrically Stimulating the Brain May Restore Movement After Stroke

Findings Suggest Potential for Brain Implants to Treat Stroke Patients

UC San Francisco scientists have improved mobility in rats that had experienced debilitating strokes by using electrical stimulation to restore a distinctive pattern of brain cell activity associated with efficient movement. The researchers say they plan to use the new findings to help develop brain implants that might one day restore motor function in human stroke patients.

After a stroke, roughly one-third of patients recover fully, one-third have significant lingering movement problems, and one-third remain virtually paralyzed, said senior author Karunesh Ganguly, MD, PhD, associate professor of neurology and a member of the UCSF Weill Institute for Neurosciences. Even patients who experience partial recovery often continue to struggle with “goal-directed” movements of the arms and hands, such as reaching and manipulating objects, which can be crucial in the workplace and in daily living.

Headshot of Karunesh Ganguly, MD, PhD, associate professor of neurology, study's senior author.
Karunesh Ganguly, MD, PhD, associate professor of neurology, study’s senior author.

 

“Our main impetus was to understand how we can develop implantable neurotechnology to help stroke patients,” said Ganguly, who conducts research at the San Francisco VA Health Care System. “There’s an enormous field growing around the idea of neural implants that can help neural circuits recover and improve function. We were interested in trying to understand the circuit properties of an injured brain relative to a healthy brain and to use this information to tailor neural implants to improve motor function after stroke.”

Over the past 20 years, neuroscientists have presented evidence that coordinated patterns of neural activity known as oscillations are important for efficient brain function.  More recently, low-frequency oscillations (LFOs)—which were first identified in studies of sleep—have been specifically found to help organize the firing of neurons in the brain’s primary motor cortex. The motor cortex controls voluntary movement, and LFOs chunking the cells’ activity together to ensure that goal-directed movements are smooth and efficient.

In the new study, published in the June 18, 2018 issue of Nature Medicine, the researchers first measured neural activity in rats while the animals reached out to grab a small food pellet, a task designed to emulate human goal-directed movements. They detected LFOs immediately before and during the action, which inspired the researchers to investigate how these activity patterns might change after stroke and during recovery.

To explore these questions, they caused a stroke in the rats that impaired the animals’ movement ability, and found that LFOs diminished. In rats that were able to recover, gradually making faster and more precise movements, the LFOs also returned. There was a strong correlation between recovery of function and the reemergence of LFOs: animals that fully recovered had stronger low-frequency activity than those that partially recovered, and those that didn’t recover had virtually no low-frequency activity at all.

To try to boost recovery, the researchers used electrodes to both record activity and to deliver a mild electrical current to the rats’ brains, stimulating the area immediately surrounding the center of the stroke damage. This stimulation consistently enhanced LFOs in the damaged area and appeared to improve motor function: when the researchers delivered a burst of electricity right before a rat made a movement, the rat was up to 60 percent more accurate at reaching and grasping for a food pellet.

“Interestingly, we observed this augmentation of LFOs only on the trials where stimulation was applied,” said Tanuj Gulati, PhD, a postdoctoral researcher in the Ganguly lab who is co-first author of the study, along with Dhakshin Ramanathan, MD, PhD, now assistant professor of psychiatry at UC San Diego, and Ling Guo, a neuroscience graduate student at UCSF.

“We are not creating a new frequency, we are amplifying the existing frequency,” added Ganguly. “By amplifying the weak low-frequency oscillations, we are able to help organize the task-related neural activity. When we delivered the electrical current in step with their intended actions, motor control actually got better.”

The researchers wanted to know whether their findings might also apply to humans, so they analyzed recordings made from the surface of the brain of an epilepsy patient who had suffered a stroke that had impaired the patient’s arm and hand movements. The recordings revealed significantly fewer LFOs than recordings made in two epilepsy patients who hadn’t had a stroke. These findings suggest that, just like in rats, the stroke had caused a loss of low-frequency activity that impaired the patient’s movement.

Physical therapy is the only treatment currently available to aid stroke patients in their recovery. It can help people who are able to recover neurologically get back to being fully functional more quickly, but not those whose stroke damage is too extensive. Ganguly hopes that electrical brain stimulation can offer a much-needed alternative for these latter patients, helping their brain circuits to gain better control of motor neurons that are still functional. Electrical brain stimulation is already widely used to help patients with Parkinson’s disease and epilepsy, and Ganguly believes stroke patients may be the next to benefit.

Other UCSF contributors to the work included Gray Davidson; April Hishinuma; Seok-Joon Won, PhD, associate adjunct professor of neurology; Edward Chang, MD, professor of neurosurgery and William K. Bowes Jr. Biomedical Investigator; and Raymond Swanson, MD, professor of neurology. They were joined by Robert T. Knight, MD, professor of psychology and neuroscience at UC Berkeley.

The research was supported in part by funding from the National Institute of Neurological Disorders and Stroke; the National Institute of Mental Health; the Agency for Science, Technology, and Research (A*STAR), in Singapore; the U.S. Department of Veterans Affairs, and the Burroughs Wellcome Fund.

 

via Electrically Stimulating the Brain May Restore Movement After Stroke | UC San Francisco

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[WEB SITE] Minimally Invasive Brain Implant Lessens Seizures

Treatment option for individuals living with refractory epilepsy now available at UC San Diego Health

UC San Diego Health now offers patients with epilepsy another non-pharmacological way to treat seizures. For the more than one million individuals who live with uncontrolled seizures despite taking medications, UC San Diego Health recently began offering the first and only FDA-approved brain-responsive neurostimulation (RNS) system designed for the treatment of refractory epilepsy.

Jerry Shih

Jerry J. Shih, MD, epileptologist and director of the Comprehensive Epilepsy Center at UC San Diego Health.

“This device is approved for use in patients who have seizures coming from up to two different locations in the brain,” said Jerry J. Shih, MD, epileptologist and director of the Comprehensive Epilepsy Center at UC San Diego Health. “When unusual brain activity is detected, the neurostimulation device sends brief painless electrical pulses with the goal of disrupting the emerging seizure and to normalize brain waves.”

Shih added, “This device provides another treatment option for patients who were previously not candidates for traditional surgery because the seizure focus was in or near important brain structures controlling memory, language or movement.”

“In clinical trials, patients treated with this device experienced substantial seizure reductions in the first year that continued to improve over time,” said Sharona Ben-Haim, MD, neurosurgeon at UC San Diego Health. “The device continuously monitors and detects the patient’s unique brain activity, allowing us to personalize treatment for each individual.”

Epilepsy is a neurological condition in which patients experience seizures, sudden surges of electrical activity in the brain. Symptoms range from brief staring spells to uncontrollable limb movements. About one in 26 people in the United States will develop a seizure disorder. Treatment with medications can control seizures for 60 to 65 percent of patients, but 35 to 40 percent of patients continue to have seizures, affecting their quality of life.

Sharona Ben-Haim

Sharona Ben-Haim, MD, neurosurgeon at UC San Diego Health.

Called the RNS System, the device is the first and only closed-loop, brain-responsive neuromodulation system. The neurostimulation system consists of a small, implantable neurostimulator connected to leads (tiny wires) that are placed in up to two seizure onset areas. The system comes with a remote monitor that patients use at home to wirelessly collect information from the neurostimulator and then transfer it to a patient data management system.

The patient’s neurologist can log into this system at any time to review accurate, ongoing information about the patient’s seizure activity and treatment progress. This helps physicians learn more about their patients’ seizures and improves patient care.

The RNS System was developed by NeuroPace, Inc. in Mountain View, CA. The system was approved by the FDA in November 2013. More than 1,300 patients have received the device nationally.

The Comprehensive Epilepsy Center at the UC San Diego Health Neurological Institute is the only nationally designated Level 4 Epilepsy Center in the region. It offers the latest technological advances in diagnostics, medical therapies, surgical procedures and clinical trials.

The epilepsy team includes epileptologists, neuropsychologists, neuroradiologists, epilepsy neurosurgeons, EEG technologists, clinical nurse specialists, and researchers.

To learn more about epilepsy treatment options at UC San Diego Health, please visit health.ucsd.edu/specialties/neuro/specialty-programs/epilepsy-center or call 858-657-7000.

 

via Minimally Invasive Brain Implant Lessens Seizures

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[WEB SITE] New `mind-controlled tech` brings hope to paralysed

These electrical signals – the same as those a doctor looks at when running an electroencephalogram (EEG) test – were sent to a computer, which “decoded” the brain waves.

Although Fritz is now only able to walk a short distance with a mechanical aid, researchers at the University of California have said the technology represents a promising yet incremental achievement in the development of brain-computer interfaces.

Mental training was initially required to reactivate the participant’s ability to use his brain power to walk, according to the study.

First, the patient was taught to control a virtual reality “avatar” with his brainwaves and given exercises to recondition and strengthen his leg muscles.

The participant later practiced walking while suspended 5cm above ground, so he could freely move his legs without having to support himself. On his 20th visit, equipped with a support system to avoid falls and take some of his body weight, he managed to put one foot after the other along a 3.66 m (12 ft) walking course.

Spinal cord stimulation using BCIs offers hope of regaining voluntary lower extremity movements to those with SCI. It would enable intuitive and direct brain control of walking via an external device. “However, independent over-ground walking is still some way off, not least because the issue of maintaining balance hasn’t yet been addressed”.

Spinal cord injuries only sever the neural connection to the legs, but the region of the brain that is responsible for sending the command to move the legs is not affected.

The breakthrough is owed to a functional electric stimulation (FES) device, which essentially acts as a communicator between Fritz’s brain and legs.

Their novel approach permitted the young man, who has complete paralysis of both legs due to spinal cord injury, to take steps without relying on manually controlled robotic limbs.

“Walking is a very fundamental behavior for us”, he said, pointing out that sitting can affect a person’s cardiovascular health or their bladder control. The computer works in such a way that it interprets received brain waves as an intention to either walk or stand still.

Researchers said the goal of testing a BCI system is to develop a brain implant that can communicate with electrodes in the legs, however researchers said a noninvasive version allows for better testing of the method.

“We hope that an implant could achieve an even greater level of prosthesis control because brain waves are recorded with higher quality”, he added.

Dr. Miguel Nicolelis, professor of neurobiology and the director for the Center of Neuroengineering at Duke University, said the study was exciting, but emphasized that the dramatic results will need to be replicated in other paraplegic patients.

Neurosurgeons made it possible by transmitting signals from the brain to electrodes placed around his knees

Source: New mind-controlled tech brings hope to paralysed – CelebCafe.org

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[WEB SITE] NeuroPace gives epileptics new hope of life without seizures

Published: April 9, 2015, 11:21 am Updated: April 9, 2015, 11:28 am

[VIDEO] –> http://kxan.com/2015/04/09/neuropace-gives-epileptics-new-hope-of-life-without-seizures/

AUSTIN (KXAN) — More than 3 million Americans suffer epileptic seizures, a neurological brain condition that can trigger convulsions or even render you unconscious, without any warning. There is a new brain implant now that can detect and stop a seizure before it begins, and the Seton Comprehensive Epilepsy Center — the only Level 4 unit of its kind in the area — has performed its first implant of the device.

“The idea is to prevent seizures from happening; it is not intended as a cure,” said Dr. Pradeep Modur, director of the program.

Seizures can hit anyone at any age for a variety of reasons. For one in three epileptics, medication cannot manage them. But the NeuroPace device can. It is a thumb-size, battery-powered computer that detects an oncoming seizure and zaps it with electrical stimulation — much the way a defibrillator works with your heart.

“It depends on the patient’s individual seizures, so you can teach the system over time what the patient’s seizures will look like,” explains Modur. “When they come back for a clinical appointment, you can tweak the system, and over time, it can get better.”

The first patient in Central Texas to receive the NeuroPace, a 41-year-old woman from East Texas, went home within two days of the surgery and will be monitored long-distance. Surgery to remove the part of the brain causing a seizure is not always an option, and that’s where the NeuroPace comes in. The surgery costs roughly $40,000 and is covered by most insurance plans and Medicare. Doctors point out that the price pays for itself in reduced hospital care and the greater productivity of a normal life without seizures.

Dr. Robert Buchanan, chief of Functional Neurosurgery at UT Dell Medical School, performed the operation here.

“This procedure, for the first time, allows those patients to be discussed again; they now have some hope,” points out Buchanan.

And hope, as they say, is powerful medicine.

via NeuroPace gives epileptics new hope of life without seizures | KXAN.com.

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