Electrical Stimulation Shows Pain-Relieving Effect

Transcranial Electrostimulation Reduces Pain in Experimental Study

Newswise — A simple, noninvasive technique providing low-level electrical stimulation of the brain produces significant pain-reducing effects in humans, reports the November issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS).

With further research and development, transcranial electrostimulation (TES) could provide a valuable, non-drug approach to reducing pain and the need for pain medications, according to the study by pain researchers at Stanford University.

Electrical Stimulation Reduces Initial and Exaggerated Pain ResponsesIn the study, ultraviolet light was used to create a small, painful area of sunburn on the upper thigh in healthy volunteers. The researchers used this technique—a standard model used to test the pain-relieving effects of drugs—to evaluate the effects of TES on pain responses.

In TES, a mild electrical current is delivered through electrodes placed around the patient's head. Two different stimulation frequencies were tested: 60 and 100 hertz (Hz). The subjects felt only a mild tingling sensation during electrical stimulation. The pain-relieving effects of TES were evaluated by means of sensory testing, with hot temperature and mechanical force applied to the sunburned skin and to undamaged skin.

The results showed that TES significantly reduced pain responses in both sunburned skin and non-burned skin in a frequency-dependent manner. Only 60 Hz TES was effective, while 100 Hz TES had little or no pain-relieving effect.

"The effects of TES on both heat and mechanical pain suggest that it may be able to diminish the exaggerated responses of the central nervous system to painful stimuli, which play an important role in the development and maintenance of many pain states," comments lead author Dr. Vladimir Nekhendzy.

The effect was limited to the time that TES was being applied. "However, there is a possibility that TES could provide lasting benefits to patients receiving multiple treatments," Nekhendzy adds.

There is a great need for new and safe approached to pain control—driven in part by the rapidly increasing use of potent morphine-related opioid drugs for pain management, according to an accompanying Editorial by Dr. Felipe Fregni of Harvard University. The idea of brain stimulation for pain control is not new: TES is in some ways similar to other types of noninvasive "brain stimulation" under study, such as transcranial magnetic stimulation and transcranial direct current stimulation. Although confirmatory research is needed, the new study "adds important data for the development of noninvasive cortical stimulation as an analgesic method," Dr. Fregni writes.

"The possibility of non-pharmaceutical approaches to pain relief is very exciting," adds Dr. Steven L. Shafer of Columbia University, Editor-in-Chief of Anesthesia & Analgesia. "The next step is to move beyond these volunteer trials to see if transcranial electrostimulation is effective in patients suffering from chronic pain."

Read the full study in Anesthesia & Analgesia

About the IARS The International Anesthesia Research Society is a nonpolitical, not-for-profit medical society founded in 1922 to advance and support scientific research and education related to anesthesia, and to improve patient care through basic research. The IARS contributes nearly $1 million annually to fund anesthesia research; sponsors an annual forum for anesthesiology leaders to share information and ideas; maintains a worldwide membership of more 15,000 physicians, physician residents, and others with doctoral degrees, as well as health professionals in anesthesia-related practice; sponsors the SAFEKIDS initiative; and publishes the journal Anesthesia & Analgesia. Additional information about the society and the journal may be found at www.iars.org www.iars.org and www.anesthesia-analgesia.org .

About Anesthesia & Analgesia Anesthesia & Analgesia was founded in 1922 and was issued bi-monthly until 1980, when it became a monthly publication. A&A is the leading journal for anesthesia clinicians and researchers and includes more than 500 articles annually in all areas related to anesthesia and analgesia, such as cardiovascular anesthesiology, patient safety, anesthetic pharmacology, and pain management. The journal is published on behalf of the IARS by Lippincott Williams & Wilkins (LWW) , a division of Wolters Kluwer Health .