DBS Eases Symptoms and May Slow Progression in Early Stage Patients, Study Says

DBS and early Parkinson's

When given to people at earlier stages of Parkinson’s disease, deep brain stimulation (DBS) reduces the complexity of their treatment, while safely providing long-term motor benefits and possibly slowing disease progression, data from a five-year pilot trial suggests.

A planned Phase 3 study has already received the go-ahead from the U.S. Food and Drug Administration (FDA). If these results are confirmed in a larger group of earlier stage patients, DBS will be the first therapy shown to be effective at slowing disease progression.

Findings were reported in the study, “Deep Brain Stimulation in Early-Stage Parkinson’s Disease: Five Year Outcomes,” published in the journal Neurology.

Deep brain stimulation is a surgical treatment for Parkinson’s disease that involves implanting a neurostimulator, a battery-operated device about the size of a pacemaker, in a person’s body to stimulate via electrical signals fine wires inserted into specific regions of the brain.

Shown to be safe and effective when used to stimulate the subthalamic nucleus (STN) — a brain region involved in movement control — in mid- to late-stage Parkinson’s patients, DBS studies in people at earlier stages are lacking. The safety and efficacy of STN DBS treatment, and its long-term effects, on this patient group are not known.

Researchers at Vanderbilt University Medical Center (VUMC) and colleagues conducted a single-site pilot trial (NCT0282152) to investigated the safety and tolerability of STN DBS in 30 people with early Parkinson’s (ages 50–75).

All, while off medication, were at stage two on the Hoehn & Yahr scale, signifying both sides of the body affected but stiffness and rigidity still at early stages. Their reliance on Parkinson’s medications ranged from six months to four years.

They were randomly assigned to either STN DBS in combination with optimal drug therapy, or to this drug regimen alone for two years.

Patients then entered an observational follow-up study (IRB040797), in which they were monitored for another three years.

Five-year data from 28 patients who completed both study parts found that those given STN DBS alongside optimal drug therapy required lower doses of levodopa to control symptoms, compared with those on an optimal drug regimen alone (a daily average of 774 mg versus 1,158 mg).

In addition to requiring lower levodopa doses, patients given STN DBS were also 16 times less likely to need multiple medications (polypharmacy) for symptom control at five years, compared with those given optimal drug therapy alone.

Through these five years, those on continuous drug therapy were seen to have an almost five times higher risk of worsening rest tremor, and a two times higher chance of a worsening of their motor symptoms in general, analyses showed.

The incidence of adverse events and the overall safety profile was similar in both treatment groups.

“These results suggest that early STN DBS + ODT is a safe Parkinson’s disease treatment with the potential to provide long-term, sustained motor benefit over standard medical therapy while reducing the need for, and complexity of, anti-parkinsonian medications and their associated complications,” the researchers wrote.

A randomized, double-blind, Phase 3 trial (IDEG050016), led by VUMC, plans to recruit about 130 patients from 20 U.S. centers, to investigate the potential of DBS in slowing disease progression when early in the course of the disease.

“With this pilot study, we’ve shown that if DBS is implanted early it’s likely to decrease the risk of progression, and if this is borne out in our larger study it would be a landmark achievement in the field of Parkinson’s disease,” David Charles, MD, a professor and vice chair of neurology at VUMC, and the study’s senior author of the study, said in a press release.

Given the one trial’s preliminary nature, however, Charles stressed its findings should not lead to any changes in clinical treatment of Parkinson’s.

The Neurology study received partial support from Medtronic, which manufactures the DBS system. Its authors, all with VUMC, also report that they had full editorial independence.

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FDA Approves Medtronic’s Percept PC Deep Brain Stimulation System

Nuplazid NDA

The U.S. Food and Drug Administration (FDA) has approved the Percept PC Neurostimulator by Medtronic, designed to allow for a more individualized use of deep brain stimulation therapy in people with Parkinson’s disease and related disorders.

While this device is the fourth deep brain stimulation (DBS) system to be approved in the U.S., it is the first system able to sense and record brain signals while therapy is delivered. As such, it is expected to help doctors more precisely tailor treatment to a patient’s needs.

“Percept uses BrainSense technology, which captures brain signal data from implanted brain leads, combined with a patient diary system,” Joohi Jimenez-Shahed, MD, professor of neurology at Icahn School of Medicine at Mount Sinai, said in a news release by the Michael J. Fox Foundation.

“This device allows us to measure and record brain signals, which can be matched with a person’s symptoms as reported in the diary or what we see on exam. By looking at brain signals, we might be able to tell whether symptoms relate to medication wearing off or to dyskinesia, for example, and we can use this information to more precisely understand how a patient’s symptoms respond to DBS,” Jimenez-Shahed said.

“Eventually, we hope to be able to use this data to adjust DBS settings for more tailored and targeted treatment,” she added.

DBS is used to treat neurological disorders that include Parkinson’s, essential tremor, dystonia, epilepsy, and obsessive-compulsive disorder. Therapy is delivered via a small, implantable device that is somewhat similar to a pacemaker. Tiny wires inserted in the brain are used to send electrical signals from the device to specific brain regions, aiming to ease motor symptoms.

Percept is also the first approved DBS system that can be used in certain full-body MRI scans, allowing greater access to imaging for patients and clinicians, Medtronic reports in a press release.

The first U.S. center to implant the device will be the Mayo Clinic in Rochester, Minnesota, it added.

“Our goal is for patients to regain independence, and we know that DBS can significantly improve motor function in people with Parkinson’s disease compared to standard medication alone,” said Bryan Klassen, MD, a neurologist at the Mayo Clinic.

“As with any therapy, considering DBS and choosing between specific devices is about weighing pros and cons,” Jimenez-Shahed said. “Because Percept is a new approach, doctors and patients will learn together in the months ahead who are the best candidates for the new technology and the best ways to take advantage of what it has to offer.”

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Newer MRI Approaches May Allow Tremor To Be Treated Without Surgery

MRI techniques

New magnetic resonance imaging (MRI) techniques capable of zeroing in on a pea-size region of the brain responsible for movement control may allow physicians to treat patients with Parkinson’s disease or essential tremor without having to resort to invasive brain surgery.

These methods were described in the study, “Advanced MRI techniques for transcranial high intensity focused ultrasound targeting,” published in the journal Brain.

Parkinson’s disease and essential tremor are neurological disorders characterized by lack of movement control that is thought to stem from defects in a small region of the thalamus, called the intermediate nucleus, in the brain.

Although first-line treatment for involuntary tremors consists on a combination of medications, this is not effective in about a third of all patients.

In the late 1990s, deep brain stimulation (DBS) — a surgical treatment that involves implanting a device to activate specific brain regions with electrical signals generated by a battery — started being used in non-responsive patients.

More recently, magnetic resonance guided high intensity focused ultrasound (MR-HIFU) — a non-invasive, image-guided therapy that allows physicians to burn (ablate) small pieces of tissue with precision using ultrasound heat waves — started being used to destroy the small region, the  intermediate nucleus, causing tremors in these people.

Unlike DBS, MR-HIFU does not require surgery to open the skull and implant a device, and can be performed without anesthesia while patients are awake.

The main challenge has been locating the exact region within the thalamus where the intermediate nucleus is located.

Although conventional computed tomography (CT) and MRI scans allow surgeons to identify regions that ought to be removed, both methods lack the resolution necessary to visualize the intermediate nucleus, a tiny pea-size region, for MR-HIFU targeting.

Researchers at UT Southwestern and colleagues described three new MRI techniques that allow doctors to spot and eliminate this region, without damaging nearby areas and risking permanent walking impairments and slurred speech.

“The benefit [of using these techniques] for patients is that we will be better able to target the brain structures that we want. And because we’re not hitting the wrong target, we’ll have fewer adverse effects,” Bhavya R. Shah, MD, an assistant professor of radiology and neurological surgery at UT Southwestern’s Peter O’Donnell Jr. Brain Institute, and the study’s first author, said in a press release.

Diffusion tractography, the most widely studied, is possibly the most promising of these three. It generates high-resolution 3D images based on the natural movement of water inside brain tissue.

“Currently, diffusion tractography is the technique that has demonstrated the most promise with multiple studies showing its clinical utility” for both DBS and MR-HIFU, the researchers wrote.

The second method, known as quantitative susceptibility mapping, is able to create high-contrast images of the brain due to its ability to pick up distortions in the magnetic field caused by the presence of certain substances in tissues, like blood or iron.

Fast gray matter acquisition TI inversion recovery, the third approach, enables doctors to visualize gray matter brain structures with high detail by turning white matter regions dark and gray matter regions white.

Gray matter refers to areas made up of neuron cell bodies, and white matter to areas made up of myelinated nerve segments (axons) that connect gray matter areas and are responsible for  transmitting nerve signals.

All three MRI techniques have already been approved by the U.S. Food and Drug Administration for use with people. Physicians at UT Southwestern are planning to start using them with patients when the Center’s Neuro High Intensity Focused Ultrasound Program opens in the fall.

“Bilateral MRgHIFU [MR-HIFU] thalamotomy clinical trials, now underway, will rely on improved targeting methodologies to reduce adverse effects and improve patient outcomes,” the research team added.

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Light-based DBS Method Can Alleviate Motor Symptoms of Parkinson’s, Animal Study Shows

STN neurons and DBS

Scientists have developed a new light-based deep brain stimulation method that when applied to neurons located in the subthalamic nucleus (STN) — a brain region involved in controlling movement — alleviated motor symptoms in a rat model of Parkinson’s disease.

The study detailing that research, “Frequency-Specific Optogenetic Deep Brain Stimulation of Subthalamic Nucleus Improves Parkinsonian Motor Behaviors,” was published in The Journal of Neuroscience.

Deep brain stimulation (DBS) is a surgical treatment for Parkinson’s disease that involves implanting a device to activate specific regions of the brain with electrical signals generated by a battery-operated neurostimulator.

When used to stimulate the STN, DBS can effectively alleviate motor symptoms of the disease. However, up until now, the “true“ therapeutic targets of DBS responsible for its beneficial effects remained unclear.

This was mostly because the electrical signals used in DBS stimulate not only neurons, but also other cell types found in the STN, making the real therapeutic targets of DBS difficult to identify with conventional methods.

“If you think of the area of the brain being treated in deep brain stimulation as a plate of spaghetti, with the meatballs representing nerve cell bodies and the spaghetti representing nerve cell axons [nerve fibers], there’s a longstanding debate about whether the treatment is affecting the spaghetti, the meatballs or some combination of the two,” Warren Grill, PhD, professor of Biomedical Engineering at Duke University and senior author of the study, said in a news story.

“But it’s an impossible question to answer using traditional methods because electrical deep brain stimulation affects them both as well as the peppers, onions and everything else in the dish. Our new light-based method, however, is capable of targeting just a single ingredient, so we can now begin teasing out the individual effects of activating different neural elements,” Grill said.

The new light-based method uses optogenetics, a technique that combines light flashes and genetic engineering to allow researchers to control the activity of specific cells of interest.

In this case, investigators genetically modified STN neurons to make them produce an ultrafast light-sensitive opsin, called Chronos. Opsins are ion channels found on cell membranes that can be activated using specific light flashes. Chronos is an ultrafast opsin that is able to respond to 130 light flashes per second, which is equivalent to the frequency of electrical stimulation normally used in standard DBS.

To assess if STN neurons could be the therapeutic target of DBS, Grill and his team stimulated genetically-modified neurons in the brain of a rat model of Parkinson’s with 130 light flashes per second.

They found that when applied at a high frequency rate, the new light-based DBS method alleviated motor symptoms of Parkinson’s in the animals, mimicking the effects of electrical DBS. However, if applied at a lower frequency rate, the new approach failed to provide significant benefits.

In addition to demonstrating that STN neuron stimulation was sufficient to lessen motor symptoms of the disease, the new study also highlighted the therapeutic potential of the new light-based DBS method.

With the new method, investigators now have the opportunity to use DBS in specific subsets of cells in particular regions of the brain. This will allow them to pinpoint not only which areas of the brain should be stimulated to obtain specific effects, but also to devise personalized therapies to manage Parkinson’s motor symptoms more efficiently.

The team is planning to use the same approach to assess the possible contribution of STN nerve fibers known as the hyperdirect pathway — the “spaghetti” in the dish — in alleviating motor symptoms of the disease.

“This is very important because somewhere in that big bowl of spaghetti are some elements that are responsible for treating symptoms and some elements that generate side effects,” Grill said.

“And if we can figure out which is which, we can design electrode stimulation geometries and patterns to target the elements that suppress symptoms while leaving the others alone,” he added.

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Brian Grant Foundation Launches Online Education Program for Exercise Pros

Grant's Army

The Brian Grant Foundation (BGF) has opened a new online education program that seeks to help exercise professionals provide safe and effective classes for Parkinson’s disease (PD) patients.

Called Grant’s Army, the program features a compilation of cutting-edge PD exercise research, case studies of exercise programs nationwide, and stories about patients who use fitness classes to help deal with symptoms. There also are video tutorials demonstrating activities known to help patients manage the neurodegenerative disorder that affects about seven to 10 million people globally.

“Research has found that exercising on a consistent basis is one of the best tools that people with Parkinson’s can use to manage symptoms of their disease,” Katrina Kahl, the foundation’s executive director, said in a press release. “Our goal with Grant’s Army is to ensure that exercise professionals are equipped with knowledge of evidence-based activities that are safe for people with Parkinson’s, and have been shown to effectively manage the symptoms.”

Exercise is important for those living with PD because it helps maintain balance, mobility and the ability to perform daily tasks. Researchers have found that patients who exercise at least 2.5 hours weekly also experience a slower decline in quality of life.

Specifically, research has indicated that exercise can lessen PD-associated tremor and improve gait, balance, flexibility, grip strength and motor coordination. Exercise also may improve cognition and lessen depression and fatigue, but studies in these areas remain ongoing.

A Grant’s Army’s patient profile features former pickup basketball player, long-distance swimmer and marathon runner Dale Moss, who experienced improvements in gait and balance after incorporating more Parkinson’s-specific exercises into his fitness routine.

Living with PD for about a decade, Moss enjoys the Parkinson’s fitness program at Northwestern Medicine Lake Forest Hospital in Illinois, where he has participated in clinical trials and had deep brain stimulation surgery (DBS) three years ago. DBS is a neurosurgical procedure in which doctors implant thin metal wires in the brain that send electrical pulses to help control some motor symptoms.

“I’m not always as steady as I want to be,” Moss stated on a program webpage. “These days I’m more focused on exercises that target Parkinson’s rather than doing some of those more grandiose events I used to do in the past. That’s the direction I’m going now athletically. I know that I need to be working out every day.”

He said he focuses on exercises such as squats, lunges and those that help improve balance. “These are the types of exercises that will help improve my quality of life and make it easier to do things like get up out of chairs.”

With a focus on PD exercise, nutrition and emotional health programs, the 20-year-old Brian Grant Foundation offers evidence-based tools to enhance patients’ well-being. Since 2016, the BGF has been training exercise experts on activities specifically for individuals with Parkinson’s. Its Exercise for Parkinson’s training program for professionals is offered online as well as in person.

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New Brain Pathway Key to Movement Found in PD Patients, Study Reports

new brain pathway

Placing electrodes directly in the brains of people with Parkinson’s disease revealed a “hyperdirect” pathway between two regions of the brain responsible for movement and cognition, a study reported.

This pathway was shown to be important in being able to stop body movements once initiated. Modulating or controlling this pathway may be a therapeutic strategy for treating movement disorders such as Parkinson’s.

The study, “Prefrontal-Subthalamic Hyperdirect Pathway Modulates Movement Inhibition in Humans,” was published in the journal Neuron

Parkinson’s disease is characterized by a progressive loss of coordination and movement leading to involuntary tremors and other motor symptoms.

Stopping a body movement that has already been initiated is important for motor control, which is thought to be mediated by a pathway between two regions in the brain. The pathway connects the subthalamic nucleus (STN), which is involved in many complex motor and non-motor functions, and the inferior frontal gyrus (IFG), associated with cognition.

“This pathway is critical to controlling movement overall,” Witney Chen, a graduate student at the University of California, San Francisco (UCSF) and the study’s first author, said in a news story.

“We’re interested in understanding how the brain controls the ways we can stop movement because when this control isn’t functioning properly, it can result in movement disorders such as Parkinson’s,” Chen said.

“This is more than just being able to quickly stop your step into the street if you see oncoming traffic,” she added.

Evidence suggested that the STN-IFG pathway exists in animals. However, only indirect imaging studies have supported its importance in humans, and in the workings of Parkinson’s disease.

To explore this pathway, Chen and colleagues based at UCSF designed a study involving 21 Parkinson’s patients in which electrodes were placed directly in the brain in both the IFG and STN regions. The goal was to gather as much information as possible about this pathway in humans.

“It’s a wonderful opportunity to study the human brain as an intact system,” said Philip Starr, MD, PhD, co-director of the UCSF Surgical Movement Disorders Center and the study’s senior author.  “And fortunately, Parkinson’s patients are especially eager to volunteer. They’re often people who had normal lives for a long time, and now they have this disorder and they really want to contribute to understanding and treating it.”

“These experiments can really only be done well with invasive electrodes at both ends of the pathway,” Starr added.

The Parkinson’s patients enrolled in the study were already scheduled to have electrodes implanted in the STN region of the brain, a standard procedure for deep brain stimulation (DBS), often used on those with mid-stage disease. As there are no pain receptors in the brain, the participants are awake during surgery and can confirm the placement and function of the DBS implants with physicians. 

During the procedure, electrodes also were placed on the surface of the brain, about five centimeters (2 inches) from the DBS implants. Chen noted that these electrode could easily be removed after the experiments.

The team then recorded high-resolution electrical impulses focusing on location and time. They found the response to STN stimulation was detected very quickly (low latency) in the IFG region, which demonstrated a “hyperdirect” connection between these two parts of the brain. 

A second experiment was conducted to measure the ability to stop a body movement. Here, patients were shown either a right or left arrow on a screen as a “go” signal, to which they responded by pushing a respective right or left button in response. Randomly, they received a “stop” signal after the “go” signal and the time taken to stop movement was measured.

The results showed that the longer the IFG and STN signals were simultaneously activated — representing a higher synchronization between both regions — the faster the participants stopped their action, and that faster initiation of activity was found to be important for successful stopping. These findings, shown across all participants tested, demonstrated a direct synchronization between these two brain regions in movement control.

Although movement inhibition has been found to be impaired in people with Parkinson’s, the team did not find physiological factors or stopping behaviors to be associated with parkinsonian severity, as assessed by the Unified Parkinson’s Disease Rating Scale.

“Our study is the first to show that the hyperdirect circuit co-modulation is linked to stopping behaviors, which has broad implications for stimulation-based therapies to treat maladaptive movement inhibition,” the scientists concluded. 

“These findings may inform therapies to treat disorders featuring perturbed movement inhibition,” they added. 

The next step is to study the role of the IFG and STN pathway in more real-life settings using electrodes that can record brain activity over longer periods of time, the researchers said. 

“Using this technology, we can start to tease apart what this circuit is doing in real life when people are moving, talking, walking, playing music or sports or whatever they want to do,” Chen said. 

“We’re really pursuing these therapeutic aspects, because we think modulation in this circuit can translate to better clinical outcomes,” she concluded.

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Imaging Technique Finds Key Neurons in Brain Interact, May Support More Targeted Treatments

nerve cell communication

Two key types of brain nerves cells affected by Parkinson’s disease — cholinergic neurons and dopaminergic neurons — communicate and interact via signaling systems, researchers were able to “see” using a new imaging approach.

This beneficial neuron-to-neuron interaction, confirmed through the novel approach in a rat model of the disease, also supported further work on targeted treatments for Parkinson’s, including a potential gene therapy.

Their study, DREADD Activation of Pedunculopontine Cholinergic Neurons Reverses Motor Deficits and Restores Striatal Dopamine Signaling in Parkinsonian Rats,” was published in Neurotherapeutics.

Parkinson’s is a progressive neurodegenerative disease, meaning that it steadily worsens as neurons die over time. One of its hallmarks is the loss of dopamine — a neurotransmitter crucial for coordinating movement and regulating mood — that occurs when dopaminergic neurons in a brain structure called the substantia nigra malfunction and die.

Cholinergic neurons — those that produce the neurotransmitter acetylcholine — are nerve cells found in the pedunculopontine nucleus (PPN) of the brain. They are also implicated in Parkinson’s, since in post mortem studies of patients’ brain tissue a significant amount of these cells are found dead.

Researchers had previously used used a harmless virus to deliver a genetic modification to cholinergic neurons in a rat model of Parkinson’s disease. This technique is called designer receptors exclusively activated by designer drugs (DREADDs), and consists of a class of engineered proteins that allow researchers to hijack cell signaling pathways in order to look at cell-to-cell interactions more easily.

The animals were then given a compound designed to activate the genetic ‘switch’ and stimulate the target neurons. After treatment, almost all animals had recovered and were able to move.

Now, this same research team used positron emission tomography (PET), a brain imaging technology, together with DREADDs to selectively activate cholinergic neurons in the brains of diseased rats and look at how other brain cells responded.

They found that stimulating cholinergic neurons led to the activation of dopaminergic neurons in the rat brain, and dopamine was released.

This means that cholinergic activation restored the damaged dopaminergic neurons. The parkinsonian rats appeared to completely recover — they were able to move without problems and their postures returned to normal.

“This is really important as it reveals more about how nerve systems in the brain interact, but also that we can successfully target two major systems which are affected by Parkinson’s disease, in a more precise manner,” Ilse Pienaar, PhD, a researcher at the University of Sussex and Imperial College London and study author, said in a press release.

“While this sort of gene therapy still needs to be tested on humans, our work can provide a solid platform for future bioengineering projects,” Pienaar added.

This new technique has several advantages over deep brain stimulation (DBS), a surgical procedure that sends electrical impulses to the brain to activate the neurons.

Deep brain stimulation can help to relieve some Parkinson’s symptoms, but is invasive and has had mixed results. Some patients show improvements while others experience no changes in symptoms or even a deterioration. This may be due to therapy imprecision, as DBS stimulates all types of brain nerve cells without a specific target.

This study sought to address the selectivity issue by looking at the activation of one type of cell in a specific part of the brain to get a better understanding of how other parts might be influenced.

“[T]he current data could allow for designing medical approaches capable of improving the ratio between desirable and undesirable outcomes and leaving nonimpaired functions intact. For example, specific genetically defined neurons … could be targeted to treat motor symptoms of [Parkinson’s], without inducing a cognitive detriment, and vice versa,” the researchers wrote.

“For the highest chance of recovery, treatments need to be focused and targeted but that requires a lot more research and understanding of exactly how Parkinson’s operates and how our nerve systems work,” Pienaar said. “Discovering that both cholinergic and dopaminergic neurons can be successfully targeted together is a big step forward.”

The researchers concluded, “[t]his study supports the hypothesis that it is the cholinergic neuronal population, projecting from the PPN, which delivers some of the clinical benefits associated with PPN-DBS.”

Pienaar and colleagues collaborated with Invicro, a precision medicine company, for this study. Lisa Wells, PhD, a study co-author on the study and Invicro employee added, “It has been an exciting journey … to combine the two technologies [DREADD and PET] to offer us a powerful molecular approach to modify neuronal signaling and measure neurotransmitter release. We can support the clinical translation of this ‘molecular switch’ … through live imaging technology.”

This work may make possible more selective and more effective treatment alternatives to deep brain stimulation.

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Glassy Carbon Electrodes Safer Than Metal in MRIs, Study Suggests

glassy carbon electrodes

Implantable electrodes made of glassy carbon may be safer for use in MRI scans than traditional electrodes made of metal for people who undergo deep brain stimulation, a new study shows.

The study, “Glassy carbon microelectrodes minimize induced voltages, mechanical vibrations, and artifacts in magnetic resonance imaging,” was published in Microsystems & Nanoengineering.

In cases where Parkinson’s patients are not responding well to medication, deep brain stimulation (DBS) can be used to treat motor symptoms associated with this neurodegenerative disease. The treatment involves surgically implanting an electrode directly in the brain, then using that electrode to electrically stimulate specific brain regions.

Traditionally, electrodes used for DBS have been made of metal, most typically platinum. But metal electrodes pose a problem when a person needs to undergo an MRI scan. Such scans can be used to image the brain using powerful magnets, but those magnets can interact badly with metal electrodes.

Specifically, the electrodes can lead to large “white spots” on the MRI images themselves, which can limit the utility of the images. Plus, the magnetic fields generated in MRI can cause electrodes to vibrate, or they can generate electrical currents that make the electrode heat up. These circumstances run the risk of causing damage or irritation in the brain.

In the new study, researchers wondered if electrodes made of glassy carbon, instead of metal, would be resistant to these issues. Glassy carbon (GC) is basically a bunch of very thin layers of carbon pressed together.

The researchers previously had created GC-based electrodes designed for DBS, and in a previous study, they showed that these electrodes were more durable than traditional platinum ones.

“Inherently, the carbon thin-film material is homogenous—or one continuous material—so it has very few defective surfaces. Platinum has grains of metal which become the weak spots vulnerable to corrosion,” Sam Kassegne, PhD, a professor at San Diego State University (SDSU) and co-author of both studies, said in a press release.

The researchers tested their GC electrodes in an MRI; but, rather than using actual human brains, they implanted the electrodes in a substance sort of like Jell-O. The researchers demonstrated that, while the metal electrode created a bright white patch on the MRI images themselves, the CG was nearly invisible — suggesting that, in an actual brain, this type of electrode would interfere with imaging far less.

They measured the currents generated in these electrodes during an MRI scan, as well as how much they vibrated, and compared these measurements to similar measurements obtained using traditional metal probes.

They found that the current generated in the GC electrodes was about 10 times lower than that in the metal probes. Similarly, vibrations in the GC electrode were about 40 times weaker than those in the metal ones, Researchers noted, however, that “for both types of microelectrodes, the measurable forces were below the detection limit” — that is, the vibrations were very small for both, even if they were smaller for the GC electrode.

“Our lab testing shows that unlike the metal electrode, the glassy carbon electrode does not get magnetized by the MRI, so it won’t irritate the patient’s brain,” said Surabhi Nimbalkar, study co-author and doctoral candidate at SDSU.

Although the researchers noted that they did not directly assess heating of the electrodes, which may be an avenue for further study, they nonetheless concluded that “GC microelectrodes demonstrate superior behavior with respect to MR safety compared to [platinum]-based electrodes.”

“Since GC has recently been demonstrated to have a compelling advantage over other materials for neural stimulation (…), this MRI compatibility validated in this study offers an additional advantage for long-term in vivo use in clinical settings,” they wrote.

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Activa Patient Programmer for DBS Therapy Available in US, Medtronic Announces

DBS technology

Medtronic, a medical technology company, announced that its Activa patient programmer technology for deep brain stimulation (DBS) therapy is now available to U.S. patients with Parkinson’s disease (PD) and other movement disorders.

The new programmer, approved by the FDA in July, is used with a customized Samsung mobile device to help patients more easily use DBS treatment and in a home setting. The Ireland-based company said that more than 150,000 people have been implanted with its DBS devices globally to manage disease symptoms, particularly those of Parkinson’s, since 1997.

“It is important for patients to have access to advanced technology for user-friendly therapy management at home,” said Sandeep Thakkar, DO, neurologist and movement disorder specialist at Hoag’s Pickup Family Neurosciences Institute, in a press release.

“The new Medtronic DBS Activa Patient Programmer device is an innovative tool that combines familiar consumer technology with medical devices, which facilitates better control for patients in an easier, more accessible way,” Thakkar said.

DBS is a surgical treatment option for people in advanced stages of Parkinson’s, whose movement problems are not being helped by medications. During surgery, one or more wires are inserted deeply into the brain to reach affected areas. These wires are subsequently connected to a pacemaker-like implantable pulse generator that is typically positioned just under the patient’s skin, in the upper thoracic region.

Able to share patient data directly with clinicians, the Patient programmer includes a programmer handset and communicator. When patients wish to modify prescribed therapy settings, check the battery, or activate or deactivate therapy, they hold the communicator above the implanted device and use the programmer to make adjustments.

Clinicians also have the ability to define settings and work with patients to adjust DBS therapy settings when using the therapy away from the clinic.

The system is managed on a Samsung Galaxy Tab S2 tablet with a customized user interface and five-inch touchscreen, and uses Samsung’s security technology to help protect both the device and patient.

Taher Behbehani, head of the Mobile B2B Division, Samsung Electronics America, said the user-friendly therapy marries safety with data control. Medtronic has partnered with Samsung since 2013, expanding into neuromodulation two years later.

“It’s through our open yet secure mobility platform that we can offer this level of customization on our market-leading devices,” he said.

“Medtronic has been the leader in DBS therapy for over 25 years. This launch continues to serve as further evidence of our dedication to our DBS patients,” said Mike Daly, vice president and general manager of the Brain Modulation business, which is part of Medtronic. “With this device, patients gain confidence, as they are able to discreetly manage their DBS therapy no matter where they are.”

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More Years of Schooling Linked to Better Response to DBS in Small Study

DBS and education

The more years of formal education that people with Parkinson’s disease have, the better they seem to respond to deep-brain stimulation — as seen in a greater ability to “dual-task,” or engage in higher-level thought while walking, a study suggests.

Education level affects dual-task gait after deep brain stimulation in Parkinson’s disease” was published in the journal Parkinsonism & Related Disorders.

Dual-tasking (DT) measures an individual’s ability to carry out a cognitive task (such as counting, or naming words that start with a particular letter) while engaging in a motor skill like walking. As such, it can be a helpful proxy for clinically relevant measures of a patient’s ability to perform everyday life tasks, which rarely come one at a time. Cognitive and motor skills are both impacted by Parkinson’s, and having to move while thinking a bit can increase the risk of falls.

Deep brain stimulation (DBS) is a surgical treatment for Parkinson’s that involves implanting a device to stimulate targeted regions of the brain with electrical impulses generated by a battery-operated neurostimulator.

Previous studies on DBS have yielded conflicting results about whether this intervention can improve dual-tasking. The researchers behind this study wondered if this conflict exists because DBS improves dual-tasking in some people with Parkinson’s, but not for others.

They recruited 34 people with Parkinson’s (average age 60.5, 44% female) and measured their DT-related gait changes a few months before DBS and again a year after DBS.

Based on these measurements, participants were divided into two groups: 18 were “responders,” meaning they had significant improvements for four dual-task assignments at the second measurement (i.e., forward and backward counting, and phonemic and semantic fluency); the remaining 16 were “non-responders” who showed no such improvement.

Cognitive reserve — the brain’s ability to improvise and find alternate ways of preforming a task — can account for differences between individuals in “susceptibility to age- or pathology-related brain changes” and has been studied in Alzheimer’s disease. Importantly, in Parkinson’s disease, higher cognitive reserve is associated with milder cognitive and motor deficits.

Education is known to contribute to cognitive reserve. As such, the researchers also divided the participants based on the highest education level they had completed: primary (through 8th grade), secondary (high school), or ‘high level’ (baccalaureate/university studies of up to 12 years).

Among the 16 non-responders, seven had completed a primary education level, four a secondary, and five had a high level. Among the 18 responders, one had completed primary level schooling, eight secondary, and nine had university level.

Responders were more likely to have completed more years of formal education, with further analyses showing that this association was statistically significant.

Other factors analyzed — including levodopa dose, Unified Parkinson Disease Rating Scale (UPDRS) score, and measurements of cognitive function and memory — were not significantly different between the two groups.

“Educational status affects DT-related gait changes one year post-DBS in [Parkinson’s disease],” the researchers concluded, noting that “a high [cognitive reserve] could be considered as a favourable inclusion criterion for future DBS candidates.”

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