Electroacupuncture
What is it and how does it work
Electrical stimulation for pain was first described in 46 AD by the Roman physician and pharmacologist Scribonius Largus.
The first Electroacupuncture (EA) in Europe began in the 19th century. Early it was used mostly for pain, but more recent work has shown good results in treating musculoskeletal, neurological, obstetric and gastrointestinal conditions as well as intraoperative and postoperative analgesia.
There is a growing interest in using EA in combination with general anaesthesia to reduce post op opioid demands, post op ileus and nausea and improve cardiovascular stability.
EA is a specialized therapeutic method in which a small electrical charge is applied to needles that are already inserted into specific points (Acupuncture points). We use a low or mixed low/intermediate (2/15 Hz EA) frequency of electrical stimulation, with slower onsets but longer effects that built with repeat treatments.
EA blocks pain by activating a variety of bioactive chemicals through peripheral, spinal, and supraspinal mechanisms. These include opioids, which desensitize peripheral nociceptors and reduce pro-inflammatory cytokines peripherally and in the spinal cord, and serotonin and norepinephrine. It depends on the frequency of electrical stimulation which opioid peptids are going to be released.
- Lower frequencies (2Hz) – endomorphin
- slightly higher frequency (15 Hz) – endomorphin, enkephalin, β-endorphin
- higher frequencies (100Hz) – dynorphin
There is still a lot unknown about endogenous opioids, but endorphins seem to be more important with chronic pain and enkephalins & endomorphins with acute pain.
There a different types of nerve fibres. The ones that we are interested in and their response to EA:
- Aα – muscle twitch may occur
- Aβ – numbness and tingling
- Aδ – pricking, ache, pressure, distension
- C – dull ache, pain, warmth, coolness
The main ones we want to stimulate are Aβ and Aδ. C- fibres are more involved in chronic pain and using too many needles you may run the risk of activating too many C-fibres.
When to use EA
- chronic pain
- poor response to dry needle acupuncture
- post op pain management
- weak and / or atrophied muscle – neurogenic or disuse atrophy
- muscle spasticity
- poor healing wounds
- surgical analgesia
- headshaking in horses
When NOT to use EA
- cardiac arrhythmias
- epilepsy
- shock, fever
- weak, hypotension
- anxious, agitated
- pregnancy
