Posts Tagged deep brain stimulation

[WEB SITE] Depression: Electrical stimulation can ‘significantly’ improve mood

New research shows that deep brain stimulation can tackle treatment-resistant depression. Stimulating a brain area called the orbitofrontal cortex led to “significant” improvements in mood for people with moderate to severe depression.
brain illustration

Using DBS to target certain key areas may relieve symptoms of severe depression.

A significant proportion of people who are living with major depression do not get any relief from existing treatments.

In fact, up to 30 percent of those affected by depression have an intractable form of the condition.

Recently, deep brain stimulation (DBS) has emerged as a potential therapy that may succeed where other treatments have failed.

In DBS, specialists surgically implant stimulating electrodes in the brain to send electrical currents to targeted areas.

In the new study, Dr. Eddie Chang and his colleagues used DBS in 25 people who had symptoms of depression. They report their findings in the journal Current Biology.

Dr. Chang is also a professor of neurosurgery at the University of California San Francisco (UCSF).

Dr. Chang explains what made the researchers focus on the orbitofrontal cortex in this study. The area “has been called one of the least understood regions in the brain,” he reports, “but it is richly connected to various brain structures linked to mood, depression, and decision-making, making it very well positioned to coordinate activity between emotion and cognition.”

The team had access to a clinic that specializes in epilepsy. People with epilepsy have electrodes surgically implanted in their brains as part of routine preparation for surgery.

For this study, Dr. Chang and team recruited 25 participants with epilepsy who also had mild to severe depression.

With the electrodes already in place, the participants reported how they were feeling a few times per day using an app. This enabled the researchers to link changes in brain activity with different moods, focusing on the brain area that was most involved in depression and also accessible with DBS.

The scientists also used mild electrical stimulation on different brain regions and asked participants to say how it affected their mood using specific keywords.

Afterward, they — with the help of a specific piece of software — quantified and analyzed the words that the volunteers had used.

The study revealed that, while stimulating most brain areas had no effect on the participants’ mood, 3 minutes of stimulating the lateral orbitofrontal cortex led to significant improvements.

The successful results were only seen among those with moderate to severe depression; there was no effect in people with mild depression symptoms.

Study co-author Kristin Sellers, Ph.D. — who is a postdoctoral researcher in Dr. Chang’s laboratory — reports on the results. “Patients said things like ‘Wow, I feel better,’ ‘I feel less anxious,’ ‘I feel calm, cool, and collected.'”

“And just anecdotally, you could see the improvements in patients’ body language. They smiled, they sat up straighter, they started to speak more quickly and naturally.”

The patterns of brain activity also supported these noticeable improvements in mood. The authors note that the participants’ brain activity after the stimulation resembled the brain activity that occurred when the volunteers reported feeling naturally good.

These […] observations suggest that stimulation was helping patients with serious depression experience something like a naturally positive mood state, rather than artificially boosting mood in everyone.”

Dr. Vikram Rao

“This is in line with previous observations,” he adds, “that [orbitofrontal cortex] activity is elevated in patients with severe depression and suggests electrical stimulation may affect the brain in a way that removes an impediment to positive mood that occurs in people with depression.”

The researchers note, however, that more studies will be needed before they can conclude that stimulating the orbitofrontal cortex improves mood in the long-term.

“The more we understand about depression at this level of brain circuitry, the more options we may have for offering patients effective treatments with a low risk of side effects,” says study co-author Heather Dawes, Ph.D.

“Perhaps by understanding how these emotion circuits go wrong in the first place, we can even one day help the brain ‘unlearn’ depression.”

via Depression: Electrical stimulation can ‘significantly’ improve mood

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[ARTICLE] Advances in closed-loop deep brain stimulation devices – Full Text

Abstract

Background

Millions of patients around the world are affected by neurological and psychiatric disorders. Deep brain stimulation (DBS) is a device-based therapy that could have fewer side-effects and higher efficiencies in drug-resistant patients compared to other therapeutic options such as pharmacological approaches. Thus far, several efforts have been made to incorporate a feedback loop into DBS devices to make them operate in a closed-loop manner.

Methods

This paper presents a comprehensive investigation into the existing research-based and commercial closed-loop DBS devices. It describes a brief history of closed-loop DBS techniques, biomarkers and algorithms used for closing the feedback loop, components of the current research-based and commercial closed-loop DBS devices, and advancements and challenges in this field of research. This review also includes a comparison of the closed-loop DBS devices and provides the future directions of this area of research.

Results

Although we are in the early stages of the closed-loop DBS approach, there have been fruitful efforts in design and development of closed-loop DBS devices. To date, only one commercial closed-loop DBS device has been manufactured. However, this system does not have an intelligent and patient dependent control algorithm. A closed-loop DBS device requires a control algorithm to learn and optimize the stimulation parameters according to the brain clinical state.

Conclusions

The promising clinical effects of open-loop DBS have been demonstrated, indicating DBS as a pioneer technology and treatment option to serve neurological patients. However, like other commercial devices, DBS needs to be automated and modernized.

Background

Deep Brain Stimulation (DBS) can be classified into open-loop (also known as conventional) and closed-loop (also known as adaptive) paradigms. Closed-loop DBS employs a sensor to record a signal linked to symptoms while open-loop DBS does not use a sensor for recording the brain condition; therefore, stimulation parameters including duration, amplitude, and frequency of the pulse train remain constant in open-loop DBS regardless of fluctuations in the disease state. The recorded signal is known as a biomarker and can have varying nature, e.g. bioelectric, physiologic, biochemical, etc. In the open-loop DBS, a specialist tracks the patient’s clinical state and manually programs the device in a trial-and-error based manner. Adjustments of stimulation parameters are not conducted in real-time based on the ongoing neurophysiological variations in the brain; therefore, adverse effects on the patient may be induced due to the brain overstimulation. On the other hand, in the closed-loop DBS, the stimulation pulses are delivered when the brain is in an abnormal state, or they are automatically and dynamically adjusted based on the variations in the recorded signal over the time. Figure 1 compares open-loop and closed-loop DBS and illustrates how they act in different brain states.

Fig. 1 Overview of open-loop DBS (a) versus closed-loop DBS (b). In open-loop DBS, a neurologist manually adjusts the stimulation parameters every 3–12 months after DBS implantation. On the other hand, in closed-loop DBS, programming of the stimulation parameters is performed automatically based on the measured biomarker. c Demonstration of two different brain states and the action of open-loop and closed-loop DBS. When the brain enters a specific state, it remains in that state for a short or long time. Closed-loop DBS gets deactivated when the brain enters the normal state. Open-loop DBS continues the stimulation regardless of the brain state

Although the conventional DBS is a successful therapy, the closed-loop DBS is potentially capable of further and more efficient improvements in neurological diseases. A systematic review of the clinical literature by Hamani et al. [1] stated that adjusting the stimulation parameters of DBS devices could reduce or abolish adverse effects reported in 142 (19%) of 737 Parkinson’s disease (PD) patients treated with subthalamic nucleus (STN) DBS. In addition, Rosin et al. [2] demonstrated the superior function of closed-loop DBS, which automatically adjusts the stimulation parameters, to alleviate PD symptoms. Moreover, Little et al. [3] indicated that motor scores in eight PD patients improved by 50% (blinded) and 66% (unblinded) during closed-loop DBS, which were 27% (p = 0.005) to 29% (p = 0.03) higher than that of open-loop DBS. Besides these therapeutic benefits, they reported 56% reduction in stimulation time, as well as a decrease in the energy requirement of the closed-loop DBS compared to open-loop DBS. Therefore, patients may also benefit from fewer surgeries for replacement of the neurostimulator battery as a result of less power consumption in non-continuous stimulations [3]. Little et al. [3] and Wu et al. [4] reported that in order to obtain similar results from open-loop and closed-loop DBS, 44% less electrical stimulation is required using closed-loop DBS, which means higher efficiency, fewer surgery numbers, lower power consumption, and longer battery lifespan.

Although DBS is a successful therapy, its operation mechanism is mainly uncertain. Hess et al. [5] explained how the temporal pattern of stimulations might have key information for clarification of the DBS mechanism. A recent short review [6] on the physiological mechanism of DBS suggests the “disruption hypothesis” in which abnormal information is prevented from flowing into the stimulation site as a result of DBS dissociation effect on input and output signals. However, it is still under debate and remains to be confirmed by more pre-clinical research. Another review by Herrington et al. [7] accounts several non-exclusive mechanisms for DBS that depend on the condition being treated and the stimulation target. Despite the existence of different theories on the DBS mechanism, there are still questions in regard to the closed-loop DBS. Does adaptive control of DBS alter the DBS mechanism? If yes, how does it alter the DBS mechanism? These questions deserve consideration in the future experimental studies.

This paper presents a comprehensive review of portable closed-loop DBS devices. While there exists a number of excellent reviews on closed-loop DBS systems [8, 9, 10, 11, 12, 13, 14, 15, 16], this work differs from the existing works as described in the following. Among the published reviews, ref. [8] mainly highlights the applications of closed-loop DBS in the rehabilitation of movement disorders. Ref. [12] mainly describes the benefits of closed-loop DBS which using local field potentials (LFPs) as the feedback biomarker. Ref. [13] mainly reviews DBS (both open-loop and closed-loop) in terms of neurological aspects and clinical benefits. Ref. [9] indicates the available biomarkers for closing the feedback loop, and gives control strategies for manipulating measured signals relating to PD patient clinical state. Ref. [10] concentrates on emerging techniques in DBS including new electrode design, new stimulation patterns, and novel targeting techniques. Ref [16] has mainly focused on selection of biomarker and its benefits and problems. Ref. [14] introduces adaptive DBS, and outlines some technological advances in DBS including stimulation type and patterns, energy harvesting, and methods for increasing life quality of patients. Similarly, ref. [15] reviews some technological advancement such as surgical targeting, DBS parameters programming, and electrode design. On the other hand, ref. [11] highlights a range of issues associated with closed-loop DBS including biomarker sensing and processing, DBS parameters programming, control algorithm, wireless telemetry, and device size and power consumption.

This paper, on the other hand, provides a comprehensive review of closed-loop DBS devices, and covers a wider range of issues and advancements associated with such devices including: (i) biomarker selection, (ii) DBS parameters programming, (iii) stimulation type and pattern, (iv) control algorithms, (v) concurrent stimulation and recording, (vi) portability, (vii) battery-less technique, (viii) user-friendly interface, and (x) remote monitoring and wireless telemetry. The paper combines the key features of the current reviews going beyond devices that are used for specific disorders or biomarkers. It covers closed-loop DBS devices reported in the latest research publications not included in the existing reviews. The paper gives a brief history of closed-loop DBS. Next, it discusses different biomarkers for closing the feedback loop. Then, it reviews the algorithms developed for controlling stimulation parameters. After that, it highlights the current challenges and limitations for implementing closed-loop DBS. Also, it reviews the technological developments in closed-loop DBS. Then, it describes commercial closed-loop DBS systems. After that, it compares research-based closed-loop DBS devices highlighting future design expectations, and giving future directions and recommendations on closed-loop DBS devices. […]

Continue —> Advances in closed-loop deep brain stimulation devices | Journal of NeuroEngineering and Rehabilitation | Full Text

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[WEB SITE] UCLA researchers use noninvasive ultrasound technique to jump-start the brain of coma patient

A 25-year-old man recovering from a coma has made remarkable progress following a treatment at UCLA to jump-start his brain using ultrasound. The technique uses sonic stimulation to excite the neurons in the thalamus, an egg-shaped structure that serves as the brain’s central hub for processing information.

“It’s almost as if we were jump-starting the neurons back into function,” said Martin Monti, the study’s lead author and a UCLA associate professor of psychology and neurosurgery. “Until now, the only way to achieve this was a risky surgical procedure known as deep brain stimulation, in which electrodes are implanted directly inside the thalamus,” he said. “Our approach directly targets the thalamus but is noninvasive.”

Monti said the researchers expected the positive result, but he cautioned that the procedure requires further study on additional patients before they determine whether it could be used consistently to help other people recovering from comas.

“It is possible that we were just very lucky and happened to have stimulated the patient just as he was spontaneously recovering,” Monti said.

A report on the treatment is published in the journal Brain Stimulation. This is the first time the approach has been used to treat severe brain injury.

The technique, called low-intensity focused ultrasound pulsation, was pioneered by Alexander Bystritsky, a UCLA professor of psychiatry and biobehavioral sciences in the Semel Institute for Neuroscience and Human Behavior and a co-author of the study. Bystritsky is also a founder of Brainsonix, a Sherman Oaks, California-based company that provided the device the researchers used in the study.

That device, about the size of a coffee cup saucer, creates a small sphere of acoustic energy that can be aimed at different regions of the brain to excite brain tissue. For the new study, researchers placed it by the side of the man’s head and activated it 10 times for 30 seconds each, in a 10-minute period.

Monti said the device is safe because it emits only a small amount of energy — less than a conventional Doppler ultrasound.

Before the procedure began, the man showed only minimal signs of being conscious and of understanding speech — for example, he could perform small, limited movements when asked. By the day after the treatment, his responses had improved measurably. Three days later, the patient had regained full consciousness and full language comprehension, and he could reliably communicate by nodding his head “yes” or shaking his head “no.” He even made a fist-bump gesture to say goodbye to one of his doctors.

“The changes were remarkable,” Monti said.

The technique targets the thalamus because, in people whose mental function is deeply impaired after a coma, thalamus performance is typically diminished. And medications that are commonly prescribed to people who are coming out of a coma target the thalamus only indirectly.

Under the direction of Paul Vespa, a UCLA professor of neurology and neurosurgery at the David Geffen School of Medicine at UCLA, the researchers plan to test the procedure on several more people beginning this fall at the Ronald Reagan UCLA Medical Center. Those tests will be conducted in partnership with the UCLA Brain Injury Research Center and funded in part by the Dana Foundation and the Tiny Blue Dot Foundation.

If the technology helps other people recovering from coma, Monti said, it could eventually be used to build a portable device — perhaps incorporated into a helmet — as a low-cost way to help “wake up” patients, perhaps even those who are in a vegetative or minimally conscious state. Currently, there is almost no effective treatment for such patients, he said.

Source: University of California – Los Angeles

Source: UCLA researchers use noninvasive ultrasound technique to jump-start the brain of coma patient

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[WEB SITE] These Brain Implants Promise To Eradicate Depression From Humanity

 Deep brain stimulation

…Despite a number of controversies (which we’ll discuss in a moment), and no matter how little doctors understand about the mechanisms behind deep-brain stimulation, it’s clear that, at least in some cases, it works wonders. In an interview with Huffington Post earlier this year, Brandy Ellis stated that the stimulator implant changed her life:

Now that I have persevered through the episode, and had the surgery, I get to build a new ‘me.’ I’m changing my behaviors beliefs, thoughts, and feelings. I am creating a new life based on what I value, because my goal has been to never return to the life I had before. I get the opportunity to implement all the tools from therapy that I have learned, with the hope that they will help me be more effective. Now that I have my implant, life is all possibilities.

And there are others who have said similar things. You can read a great first-person account of the pains of depression and the hope that an effective deep-brain stimulator brought to Liss Murphy, a Boston woman, at WBUR’s CommonHealth. And there are a number of others.

The evidence goes beyond first-person accounts. A German team trialed a deep-brain stimulation depression treatment last year and found that six of the seven patients’ symptoms improved “considerably and rapidly.” This particular study used electrical currents to target the brain’s reward system. A number of other studies have come up with similar findings.

But not everyone is convinced.

A number of people are skeptical of the efficacy of these treatments, and with good reason. First of all, while some studies have shown solid improvements in participants, a few have shown that the treatments are only as effective as more standard, less-invasive treatments. And if a treatment as risky, complicated, and expensive as implanting electrodes in the brain isn’t any more effective than prescribing medications, there’s no reason to continue studying it.

Let’s clear up what “risky” means. Any procedure that involves drilling holes in the skull is going to be risky. While neurosurgeons are really great at what they do, and take every necessary precaution, there are always going to be some risks, like infections caused by the implanted hardware, or bleeding on the brain. For the most part, the operations are safe . . . but the risk adds another factor to why some people are skeptical of the treatment.

Beyond the cost/benefit analysis of the procedure, there’s the question of whether or not we’ve studied it enough. Many of the studies have only used a handful of participants, and some of them weren’t performed in a properly scientific, controlled manner with placebos and double blinds…

more–> These Brain Implants Promise To Eradicate Depression From Humanity.

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[WEB SITE] Brain Massage | The Scientist Magazine®

Researchers may be able to improve memory by discharging magnetic pulses on the skull to alter the neural activity at and beneath the brain’s surface.

via Brain Massage | The Scientist Magazine®.

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[A review] Neurostimulation for traumatic brain injury

Abstract

Traumatic brain injury (TBI) remains a significant public health problem and is a leading cause of death and disability in many countries. Durable treatments for neurological function deficits following TBI have been elusive, as there are currently no FDA-approved therapeutic modalities for mitigating the consequences of TBI.

Neurostimulation strategies using various forms of electrical stimulation have recently been applied to treat functional deficits in animal models and clinical stroke trials. The results from these studies suggest that neurostimulation may augment improvements in both motor and cognitive deficits after brain injury. Several studies have taken this approach in animal models of TBI, showing both behavioral enhancement and biological evidence of recovery.

There have been only a few studies using deep brain stimulation (DBS) in human TBI patients, and future studies are warranted to validate the feasibility of this technique in the clinical treatment of TBI. In this review, the authors summarize insights from studies employing neurostimulation techniques in the setting of brain injury. Moreover, they relate these findings to the future prospect of using DBS to ameliorate motor and cognitive deficits following TBI.

JNS – Journal of Neurosurgery –.

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