By Femi Ogunyemi
When I told the elderly diabetic woman that her ischemic leg pain may require treatment with electrical stimulation, she grabbed her bag, leapt up and mumbled:“Na NEPA you go take treat me?” “It’s not NEPA Ma,” I smiled. “It is actually a pulse generator.” She was having none of it and headed for the door. “Electricity, NEPA, generator…..all na same family. I de come.”
It dawned on me that this very educated patient was not joking…she was truly concerned. “You de go?” I asked.
“I de come,” she repeated.
I’ve always found it interesting how we say we are “coming” when we are, in reality, “going”. “Please take this with you,” I handed her a pamphlet on electrical stimulation for the treatment of pain. I had planned to discuss this educational document with her, but, that was not to be. She had vacated her seat faster than the speed of political defections!
Electricity has indeed been used to treat pain since ancient times. The Ancient Egyptians and later the Greeks and Romans recognized that electrical fishes are capable of generating electric shocks for relief of pain. In 2500BC, during the Egyptian Fifth Dynasty, stone carvings show electric fish, Malapterurus electricus, used to treat painful conditions.
And in 400 BC Hippocrates used electric fish to treat headache and arthritis.
I won’t be surprised to find that our ancient Babalawos and witchdoctors, had they kept any records, were doing the same along our Atlantic coastline at that time too!
In the 18th and 19th centuries these natural producers of electricity were replaced by man-made electrical devices.
In 1759, Dr John Wesley’s documents described treatment of sciatica, headache, gout and kidney stone using electrical currents.
The 19th century, seen as the “golden age” of electrotherapy saw its use for dental, neurological, psychiatric and gynecological disturbances.
However, at the start of the 20th century electrotherapy fell from grace. It was dismissed as unscientific and used by quacks and charlatans for ignoble objectives.
I will not be surprised if unexpected electrocutions and mishaps went unreported.
Coincidentally, the development of effective analgesic drugs decreased the interest in electricity. In the second half of the 20th century electrotherapy underwent a revival. Based on animal experiments and clinical investigations, its neurophysiological mechanisms were elucidated in more details.
In 1965, two very clever scientists, Melzack and Wall proposed what they called the “Gate Control Theory of Pain”. This was a landmark paper. Ron Melzack, a Canadian, and Patrick Wall from the UCH London, postulated that the spinal cord, in carrying painful stimuli to the brain, has certain “gates” along the way. These gates can open and close, naturally and pharmacologically, and this ability varies between individuals. I was fortunate, though I never met Dr Wall, one of the Consultants under whom I was a Pain Management trainee at the UCH, had worked with him as a junior.
Dr Wall went on, in 1967, with a W. Sweet, to report the use of high frequency percutaneous (through the skin) electrical nerve stimulation for the relief of chronic neuropathic pain. Also in 1967, CN Shealy, et al described the use of Dorsal Column Stimulation (DCS) of the spinal cord (also called SCS)….the same, now much modernised, procedure that I had planned for my patient!
The pain relieving action of electricity is explained by two mechanisms: first, segmental inhibition of pain signals to the brain in the dorsal horn of the spinal cord and, second, activation of the descending inhibitory pathway with increased release of endogenous (body made) opioids and other neurochemical compounds.
Today’s electrotherapy for neuropathic and musculo-skeletal pain is based in on the following types: transcutaneous electrical nerve stimulation (TENS), percutaneous electrical nerve stimulation (PENS or electro-acupuncture) and spinal cord stimulation (SCS).
In mild to moderate pain, TENS and PENS are effective methods, whereas SCS is very useful for therapy of refractory neuropathic or ischemic pain.
As for my patient, she called me some days later, and said she was willing to try my “generator” since NEPA had failed her at home.