Can non-invasive neurostimulation help treat chronic pain?
Chronic pain is that pain which lasts beyond the time of one’s expected healing. Many patients e
xperience continuous pain despite having conventio
nal treatments like injections, medical and physical therapy, surgery etc. Non-invasive brain stimulation is gradually becoming a popular tool as an alternative treatment of chronic pain syndromes. tDCS has been explored in a variety of pain population with various chronic pain syndromes such as multiple sclerosis, central pain due to spinal cord injury, fibromyalgia, headaches, neuropathic and post-operative pain etc. It may non-invasively modulate cortical areas related to sensation and pain representations.
Recent evidences suggest that tDCS interacts with several neurotransmitters in the brain, such as serotonin, acetylcholine, dopamine. It also brings about changes in brain-derived neutrophic factors that deal with process of pain. It alters the
way the nervous system send messages, for example pain messages t
hat the nervous system sends when nerve cells are damaged. Furthermore, it is also said that tDCS can upregulate and downregulate the functional connectivity of brain regions that are associated with motor, cognitive and pain processing.
Effects Of TDCS On Chronic Pain In Spinal Cord Injured Patients:
Sixteen spinal cord injured patients were randomly allocated to active or sham treatm
ent groups. tDCS was administrated by placing the anode over the dominant M1 and cathode over the contralateral supra orbit scalp area. Patients received either sham or active treatment for 5 consecutive days and 20 minutes daily.
In result, no adverse effects of the treatment were seen, while treatment seemed to have reduced the pain scores on VAS.
Effects Of TDCS On Chronic Pain In Fibromyalgia Patients:
48 female patients with (45 females having) fibromyalgia were randomly investigate
d with the results of 2 mA anodal tDCS given for 5 consecutive days, 20 minutes each day. Changes in pain, stress, daily functioning and psychiatric symptoms were observed. A small but significant improvement was seen under the active tDCS treatment. Fibromyalgia related daily functioning was improved. The stimulation was also well tolerated by the patients. And no adverse effects were observed.
This study suggests that tDCS has the potential to induce pain relief in patients suffering from fibromyalgia, without any adverse effects.
Effects Of TDCS On Chronic Pain In Phantom Limb Pain Patients:
Eight patients with unilateral lower and upper limb pain were enrolled and were given anodal tDCS (applied over motor cortex) for over 5 consecutive days, 15 minutes each day. tDCS induced a sustained decrease in phantom limb pain. Moreover, the patients reported a relief in pain each day along with a better condition to move their phantom limb.
The results showed that a 5-day treatment of motor cortex stimulation with tDCS can induce stable relief from Phantom limb pain.
tDCS is a unique and fine treatment to treat chronic pain. The intensity of current used in tDCS is so low that it cannot be felt while it is applied to the skull. The studie
s have shown that tDCS affects variety of brain area in a positive way. tDCS polarizes the brain cells under the electrodes and then alters the way the brain sends and receives messages. It is believed that this polarization can reverse the abnormal brain excitability responsible for pain.
A New Treatment for Chronic Pain. (n.d.). Retrieved from Headache and pain. a centre of palm beach: http://www.palmbeachpain.com/new-pain-treatments/41-a-new-treatment-for-chronic-pain.html
Effects of Transcranial Direct Current Stimulation (tDCS) on Chronic Pain in Spinal Cord Injured Patients. (2017, march 22). Retrieved from Spine Research: https://spine.imedpub.com/effectsof-transcranial-direct-current-stimulation-tdcs-on-chronic-pain-in-spinal-cord-injured-patients.php?aid=14974
Evidence-based review of transcranial direct current stimulation (tDCS) for chronic pain syndromes. (2017, march-april). Retrieved from brain stimulation: https://w
Immediate and Sustained Effects of 5-Day Transcranial Direct Current Stimulation of the Motor Cortex in Phantom Limb Pain. (2015, april 18). Retrieved from NCBI: https://www.ncbi.nlm.nih.gov/pubmed/25863170
Stimulating the brain without surgery in the management of chronic pain in adults. (2018, april
13). Retrieved from cochrane: http://www.cochrane.org/CD008208/SYMPT_stimulating-brain-without-surgery-management-chronic-pain-adults
Transcranial direct current stimulation as a treatment for patients with fibromyalgia: a randomized controlled trial. (2015, JAN). Retrieved from NCBI: https://www.ncbi.nlm.nih.gov/pubmed/25599302