Electrically Stimulating The Brain Produces Strong Opiate-Like PainkillerMain Category: Pain / Anesthetics
Also Included In: Neurology / Neuroscience
Article Date: 03 Jan 2013
A patient with chronic, severe facial pain can use electricity on certain areas of the brain to release an opiate-like substance, one of the body's most powerful painkillers.
The finding, which was published in the journal Frontiers in Psychiatry, elaborates on prior research conducted at Harvard University, the University of Michigan, and the City University of New York where patients with chronic migraines received electricity through sensors on their skulls.
The subjects experienced a reduction in the intensity and pain of their headaches. However, the scientists could not exactly understand how or why.
The new study gives insight into what takes place in the brain that causes a decrease in pain during the electricity sessions, explained Alexandre DaSilva, assistant professor of biologic and materials sciences at the U-M School of Dentistry and director of the school's Headache & Orofacial Pain Effort Lab.
In the recent experiment, a radiotracer was intravenously given to patients with TNP (trigeminal neuropathic pain) which reached the critical brain areas involved in this persistent, severe facial pain.
During a PET scan (positron emission tomography), the experts put electrodes and electrically stimulated the skull directly above the motor cortex of the subject for 20 minutes. The stimulation is referred to as transcranial direct current stimulation (tDCS).
The radiotracer was particularly developed to indirectly calculate the local brain release of mu-opioid - a natural substance which changes the recognition of pain. It is necessary for opiate to bind to the mu-opiod receptor so that it can function.
"This is arguably the main resource in the brain to reduce pain. We're stimulating the release of our (body's) own resources to provide analgesia. Instead of giving more pharmaceutical opiates, we are directly targeting and activating the same areas in the brain on which they work. (Therefore), we can increase the power of this pain-killing effect and even decrease the use of opiates in general, and consequently avoid their side effects, including addiction."
DaSilva added that morphine and the majority of other pharmaceutical opiates target the brain's mu-opioid receptors.
The electricity administered is extremely small. The researchers explained that ECT (electroconvulsive therapy), used to treat psychiatric conditions such as depression, administers amperage in the brain varying from 200 to 1600 milliamperes (mA), while the tDCS protocol used in this study used 2 mA, significantly lower than ECT.
After only one session, the patient's threshold for cold pain improved right away by 36%, but not the subject's clinical, TNP/facial pain.
According to DaSilva, this indicates that in order to have an impact on clinical pain as seen in their prior research on migraines, repetitive stimulation over many sessions is crucial.
The scientists recently conducted a different study involving more participants, which confirmed the results of the research above. However, they pointed out that further examination is necessary.
The experts now plan to examine the long-term impact of electrically stimulating the brain and aim to identify certain targets in the brain that could be more successful being contingent on the patient's condition. For instance, people with chronic pain who also have symptoms of depression may find that the frontal areas are more effective.
Written by Sarah Glynn
Copyright: MediLexicon International Ltd
Original article posted on Medical News Today.
Articles not to be reproduced without permission of Medical News Today