Harnessing the brain’s own opiate-like painkiller to treat face pain
A potential new treatment that uses the brain's own naturally occurring painkillers could be used in the future to help people affected by trigeminal neuralgia.
Trigeminal neuropathic pain or trigeminal neuralgia is a relatively rare condition which causes attacks of pain on one side, or less commonly both sides, of the face. The pain comes and goes and usually lasts only a few seconds although this varies between individuals. The condition is named after the trigeminal nerves: one on the left side of the face and one on the right, which both pass signals onto the brain. See our page on trigeminal neuralgia for more information.
Treatments have traditionally consisted of medication or in some cases surgery, but a single case study described by researchers in America may signal a potential new treatment which uses the brain’s own naturally occurring painkillers by using transcranial direct current stimulation (tDCS).
Transcranial Direct Current Stimulation (tDCS)
tDCS is a technique which involves non-invasive stimulation of the brain using external electrodes which are placed on the head and is thought to be a beneficial treatment for neuropsychiatric disorders and chronic pain. Low level electric currents are administered through the electrodes which result in stimulation of the brain and mild side effects such as a slight tingly/itchy sensation on the scalp. In the case study described by Marcus DosSantos and colleagues, a 62 year old woman who suffered from trigeminal neuralgia was given tDCS for 20 minutes during a PET (positron emission tomography) scan. The PET scan showed that when the patient was receiving stimulation through the electrodes, the brain released mu-opioids which change the brain’s recognition of pain.
What does this mean?
After one session, the patient’s score for pain related to a cold stimulus were reduced by 30%, although the score for pain related to trigeminal neuralgia was not lowered. Despite this, there are positive findings from this study. For example, the researchers observed a significant increase in the levels of mu-opioids produced by the brain which means that multiple sessions of tDCS may prove to be beneficial. When an individual experiences long term pain, the brain rewires itself somewhat like picking up a bad habit and it’s thought that repeated mu-opioid exposure may alter and reverse this and provide a more natural treatment for trigeminal neuralgia in the future.