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2 June 2023
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Technology: Scientists decode brain signals for pain, sparking hope for chronic pain treatments
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Researchers have identified
an area of the brain associated with chronic pain, raising hopes for new
treatments. Researchers have recorded brain signals for pain for the first
time, using a machine learning technique that could lead to treatments for the
condition. They recorded pain-related data from inside the brains of
individuals who have chronic pain disorders caused by stroke or amputation. Scientists
have long sought to understand how pain is represented by brain activity. With
electrodes implanted in the heads of the patients, the researchers could record
neural activity over the course of months. Then with machine learning they
could predict the pain severity scores from neural activity.
The researchers said the findings, published in Nature Neuroscience, could provide a way forward for developing treatments for chronic pain, which is one of the largest contributors to disability worldwide.
The research was funded by two initiatives, the National Institutes of Health’s (NIH) Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) and the Helping to End Addiction Long-term Initiative.
“This is a great example of how tools for measuring brain activity originating from the BRAIN Initiative have been applied to the significant public health problem of relieving persistent, severe chronic pain,” Walter Koroshetz, director of the National Institute of Neurological Disorders and Stroke, said in a statement.
“We are hopeful that building from these preliminary findings could lead to effective, non-addictive pain treatments”.
What’s next
Traditionally, researchers gather data about chronic pain through self-reports from those living with the condition. Examples of this type of data include questionnaires about pain intensity and emotional impact of pain. This study however, also looked directly at changes in brain activity in two regions where pain responses are thought to occur--the anterior cingulate cortex (ACC) and the orbitofrontal cortex (OFC)--as participants reported their current levels of chronic pain.
"Functional MRI studies show that the ACC and OFC regions of the brain light up during acute pain experiments. We were interested to see whether these regions also played a role in how the brain processes chronic pain," said Dr. Shirvalkar. "We were most interested in questions like how pain changes over time, and what brain signals might correspond to or predict high levels of chronic pain?"
Four participants, three with post-stroke pain and one with phantom limb pain, were surgically implanted with electrodes targeting their ACC and OFC. Several times a day, each participant was asked to answer questions related to how they would rate the pain they were experiencing, including strength, type of pain, and how their level of pain was making them feel emotionally. They would then initiate a brain recording by clicking a remote-control device, which provided a snapshot of the activity in the ACC and OFC at that exact moment. Using machine learning analyses, the research team was able to use activity in the OFC to predict the participants' chronic pain state.
In a separate study, the researchers looked at how the ACC and OFC responded to acute pain, which was caused by applying heat to areas of the participants' bodies. In two of the four patients, brain activity could again predict pain responses, but in this case the ACC appeared to be the region most involved. This suggests that the brain processes acute vs. chronic pain differently, though more studies are needed given that data from only two participants were used in this comparison.
What is yet unknown
This study represents an initial step towards uncovering the patterns of brain activity that underly our perception of pain. Identifying such a pain signature will enable the development of new therapies that can alter brain activity to relieve suffering due to chronic pain. The most immediate benefit may be in informing ongoing studies in HEAL and BRAIN to employ deep brain stimulation (DBS) to treat chronic pain. Ongoing and future work involving more participants will be key in determining whether different pain conditions share the OFC activity seen in these patients or how the signatures differ among persons with different pain conditions.
More modern approaches to DBS that fine-tune the stimulation based on activity biomarkers from the brain have been used to successfully treat some brain disorders including Parkinson's disease and major depressive disorder, but those successes have required well-established brain biomarkers. For conditions such as chronic pain, the identification of biomarkers is in the early stages.
Effective and non-addictive treatments for chronic pain conditions is a main goal of NIH HEAL Initiative efforts to find scientific solutions to stem the opioid public health crisis. The findings are a key step to identifying pain-specific biomarkers toward personalizing pain management for individuals, leading to the development of new technologies and advances to better understand brain circuit, a major component of the NIH BRAIN Initiative.
Source: Euro News, Gulf News
The researchers said the findings, published in Nature Neuroscience, could provide a way forward for developing treatments for chronic pain, which is one of the largest contributors to disability worldwide.
The research was funded by two initiatives, the National Institutes of Health’s (NIH) Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) and the Helping to End Addiction Long-term Initiative.
“This is a great example of how tools for measuring brain activity originating from the BRAIN Initiative have been applied to the significant public health problem of relieving persistent, severe chronic pain,” Walter Koroshetz, director of the National Institute of Neurological Disorders and Stroke, said in a statement.
“We are hopeful that building from these preliminary findings could lead to effective, non-addictive pain treatments”.
What’s next
Traditionally, researchers gather data about chronic pain through self-reports from those living with the condition. Examples of this type of data include questionnaires about pain intensity and emotional impact of pain. This study however, also looked directly at changes in brain activity in two regions where pain responses are thought to occur--the anterior cingulate cortex (ACC) and the orbitofrontal cortex (OFC)--as participants reported their current levels of chronic pain.
"Functional MRI studies show that the ACC and OFC regions of the brain light up during acute pain experiments. We were interested to see whether these regions also played a role in how the brain processes chronic pain," said Dr. Shirvalkar. "We were most interested in questions like how pain changes over time, and what brain signals might correspond to or predict high levels of chronic pain?"
Four participants, three with post-stroke pain and one with phantom limb pain, were surgically implanted with electrodes targeting their ACC and OFC. Several times a day, each participant was asked to answer questions related to how they would rate the pain they were experiencing, including strength, type of pain, and how their level of pain was making them feel emotionally. They would then initiate a brain recording by clicking a remote-control device, which provided a snapshot of the activity in the ACC and OFC at that exact moment. Using machine learning analyses, the research team was able to use activity in the OFC to predict the participants' chronic pain state.
In a separate study, the researchers looked at how the ACC and OFC responded to acute pain, which was caused by applying heat to areas of the participants' bodies. In two of the four patients, brain activity could again predict pain responses, but in this case the ACC appeared to be the region most involved. This suggests that the brain processes acute vs. chronic pain differently, though more studies are needed given that data from only two participants were used in this comparison.
What is yet unknown
This study represents an initial step towards uncovering the patterns of brain activity that underly our perception of pain. Identifying such a pain signature will enable the development of new therapies that can alter brain activity to relieve suffering due to chronic pain. The most immediate benefit may be in informing ongoing studies in HEAL and BRAIN to employ deep brain stimulation (DBS) to treat chronic pain. Ongoing and future work involving more participants will be key in determining whether different pain conditions share the OFC activity seen in these patients or how the signatures differ among persons with different pain conditions.
More modern approaches to DBS that fine-tune the stimulation based on activity biomarkers from the brain have been used to successfully treat some brain disorders including Parkinson's disease and major depressive disorder, but those successes have required well-established brain biomarkers. For conditions such as chronic pain, the identification of biomarkers is in the early stages.
Effective and non-addictive treatments for chronic pain conditions is a main goal of NIH HEAL Initiative efforts to find scientific solutions to stem the opioid public health crisis. The findings are a key step to identifying pain-specific biomarkers toward personalizing pain management for individuals, leading to the development of new technologies and advances to better understand brain circuit, a major component of the NIH BRAIN Initiative.
Source: Euro News, Gulf News