Treatment of pain with TENS currents
Transcutaneous Electrical Nerve Stimulation
The Transcutaneous electrical stimulation (TENS) is a analgesic stimulation which is carried out with the peripheral nervous system impulses through electrodes placed on the area to be treated.
TENS stimulation is done typically with symmetrical biphasic pulses (wave) and with frequencies that can range from 8 to 200 Hz.
This type of analgesic stimulation, allowing fighting pain without resorting to drugs, uses 2 different physiological mechanisms to achieve this:
- The endogenous production of beta-endorphins and enkephalins thanks to the endorphin system with very low frequencies of stimulation (< 8 Hz). This type of stimulation, which has a slow onset, produces a general pain reliever.
- The production of serotonin and block pain signals (gate control) towards the higher nerve centers. The stimulation is made in this case with higher frequencies (from 80 Hz)
Serotonin and the mechanism of the "gate control" achieve a rapid but short-lived analgesic effect.
INSTRUCTIONS FOR APPLICATION
The TENS, biphasic, symmetrical, compensated using a current, are used in two different ways:
segmented sensory inhibition against acute and localized –
– release of endorphins to treat chronic pain and widespread.
ANALGESIC ACTION FOR SENSORY SEGMENTAL INHIBITION
In humans find themselves two snowy afferent fiber types, meaning the end of the fibers that lead information from the periphery until level brain stem. The former are large diameter fibers, called A-beta fibers, which are responsible for the conduct of tactile sensitivity from the periphery up centrally. The second, called A-delta fibers are smaller diameter, and lead to brain pain sensitivity level. A further differentiation between these two types of fiber, is the fact that the former have a low arousal threshold, while the latter show a threshold most high arousal. The pain signal path from the periphery to the Center is located, at the level of the spinal cord, an interneuron, which acts as an inhibitor signal select switch.
The current TENSby stimulating A-beta fibers of big diameter, goes to excite the inhibitory interneuron. Its activation, which prevents pain signals to the brain, get to level blocks the painful sensation.This mechanism was called, by Melzack and Wall who were those who identified in 1965, gate effect "or" Gate Control ".
In this mode of TENS stimulation impulses must be of short duration (1 < msec) with a frequency between 80 and 150 Hz. The intensity should be comfortable and produce only a tingling sensation (tactile sensitivity threshold).
To be effective the treatments will have a duration of at least 30 min.
ANALGESIC ACTION FOR RELEASE OF ENDORPHINS
Endorphins and enkephalins are proteins produced in the brain with morphine-like functions and present in different structures of the central nervous system, for this reason, particularly effective in the pain subsides.
These morfineuro natural mediators are endogenous analgesia it: you may set on receptors st mobilecerebral rutture com the thalamus, the Libyan system reticulated tissue producing pain parago sedationcan be compared to that of morphine.
Electrostimulation with TENS currents can stimulate the release of these substances Mallik-similar endogenous.
In fact, research has shown that treatments of 30 ' with low frequency currents and high intensity, capable of producing a rhythmic muscle shock almost to the threshold of pain, can raise the rate of 20% relative to baseline of endorphins. This increase is maintained in 30 min following the arrest of treatment.