In an entirely new stimulation method to combat severe pain, researchers at Lund University in Sweden have developed ultra-thin microelectrodes which are inserted into the pain centres of the brain.
This approach, which was tested in rats, provides effective and personalised analgesia, without the side effects of drugs. The findings were reported in Science Advances.
The quality of life of patients experiencing pain is greatly impacted by the lack of side-effect free treatment, and pain also impacts society in terms of reduced productivity. Side effects of pain medication can include reduced mental capacity and, in some cases, addiction. According to a recent American report, about 8% of the American population suffer from high-impact chronic pain.
To address this, professor of neurophysiology Jens Schouenborg led a research team which developed a method to combat pain via personalised stimulation using ultra-thin, tissue-friendly microelectrodes.
“The electrodes are very soft and extremely gentle on the brain. They are used to specifically activate the brain’s pain control centres without simultaneously activating the nerve cell circuits that produce side effects. The method involves implanting a cluster of the ultra-thin electrodes and then selecting a sub-group of the electrodes that provide pure pain relief, but no side effects. This procedure enables extremely precise and personalised stimulation treatment that was shown to work for every individual,” explained Prof Schouenborg.
Pain control is achieved by activating the brain’s pain control centres, these in turn block only the signal transfer in the pain pathways to the cerebral cortex.
“We have achieved an almost total blockade of pain without affecting any other sensory system or motor skill, which is a major breakthrough in pain research. Our results show that it is actually possible to develop powerful and side effect-free pain relief, something that has been a major challenge up to now,” explained first author and doctoral student Matilde Forni.
Over several years, the researchers developed a tissue-friendly, gelatine-based technology and surgical techniques that allowed them to precisely implant the flexible microelectrodes. According to the researchers, the new technique should work on all sorts of pain that are conveyed by the spinal cord, which is most types of pain.
“In our study we also compared our method with morphine, which was shown to deliver considerably less pain relief. In addition, of course, morphine has a powerful sedative effect as well as other cognitive effects. In the study we could also show that pain after sensitisation (hyperalgesia), which is common in chronic pain, was blocked”, said Prof Schouenborg.
The researchers plan to test the technology in humans and that within five to eight years yield an effective pain treatment, for pain from cancer or chronic pain in connection with spinal cord injuries, for which there is no currently satisfactory pain treatment..
The researchers also consider that the method could be used in a broader way to treat conditions besides pain.
“In principle, the method can be tailored to all parts of the brain, so we believe that it could also be used in the treatment of degenerative brain diseases such as Parkinson’s disease as well as in depression, epilepsy and probably stroke as well. The electrode technique also has applications in diagnostics and not least in research on how the mysterious brain works,” said Prof Schouenborg.
Source: Lund University