Researchers develop completely new stimulation method, using ultra-thin microelectrodes
Lund University
Researchers at Lund University in Sweden have developed a completely new stimulation method, using ultra-thin microelectrodes, to combat severe pain. This provides effective and personalised pain relief without the common side effects from pain relief drugs. The study, which was conducted on rats, has been published in the research journal Science Advances.
The lack of a side effect-free treatment for long-term pain often considerably impairs the quality of life of the patients affected. Without analgesic treatment, the persistent pain makes it difficult for the patient to function in everyday life.
Traditional pain-relieving treatment certainly reduces the
pain, but at the same time affects the senses and mental function, and there is
a considerable risk of developing a drug addiction.
Pain
also entails a considerable cost for society in the form of sick leave, healthcare
costs and lost production. According to a recent American report (https://www.cdc.gov/mmwr/volumes/67/wr/mm6736a2.htm)
about eight per cent of the American population suffer from high-impact chronic
pain.
In Lund, a research team led by professor of neurophysiology Jens Schouenborg 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," explains Jens Schouenborg.
The
pain is blocked by activating the brain's pain control centres, and 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," explains Matilde Forni, doctoral student and first author of the new
pain study.
During
the project, which has been running for several years, the researchers
developed a tissue-friendly, gelatine-based technology and surgical techniques
that made it possible to implant the flexible microelectrodes with very high
precision. According to the researchers, the new technique should work on all
sorts of pain that are conveyed by the spinal cord, i.e. most types of pain.
The
most common form of pain relief today is through the use of drugs.
"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," says Jens Schouenborg.
The
study in Lund was conducted on rats. Could the results be transferable to
humans?
"That
is the aim. The human brain has similar control systems to the rat's and our
electrode designs can be scaled up for humans," says Matilde Forni.
The
researchers hope that within five to eight years the method will lead to
satisfactory stimulation treatment of people with particularly severe pain,
such as cancer pain or chronic pain in connection with spinal cord injuries,
for which no satisfactory pain treatment is available today.
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," says Jens
Schouenborg.
