New Technique Combines Electrical Currents and Local Anesthetic for Pain Management
Numerous types of electrical currents are offered in modern electromedicine. The plethora of currents is made possible by varying the frequency, amplitude (intensity), and direction of the current in time. Within these electric current parameters are distinct and varying physiologic and therapeutic effects for the human biosystem.
Typically, therapeutic electric currents are classified according to their frequencies—for example, low frequency (LF; <2,000 Hz), medium frequency (MF; 2,000-100,000 Hz), or high frequency (HF; >100,000 Hz). This therapeutic classification system appears to originate from numerous physiologic investigations made in the last century.1-5 In the human biosystem, LF and MF currents are used for therapeutic stimulation of excitable cells (receptors, nerves, and muscles). Depending on the stimulating frequency delivered, physiologic and therapeutic actions may occur that may include vasodilatation, vasoconstriction, analgesia, activation of regeneration, and facilitation of metabolism.
This article describes a new electromagnetic device and its use in combination with local anesthetic therapy to treat pain problems.
New Advanced Technology
The vast majority of electromedical devices available in the United States employ LF stimulation (eg, transcutaneous electrical nerve stimulation [TENS]). Balanced MF currents have been developed that produce twice the electrical current with no electrical charge. A new type of electrical current technology has been developed to enhance the stimulating lower frequencies and nonstimulating middle frequencies for increased efficacy in clinical practice. The device also combines, and simultaneously delivers, frequency-modulated (FM) and amplitude-modulated (AM) electric cell currents in the MF range. We refer to this electromedical approach as electronic signal treatment (EST).
This new technology may reach deeper into tissue structures with simultaneous modulation of amplitude and frequency between 2,500 Hz and 33,000 Hz. It is also capable of modulating its MF electric cell-signaling current down into the LF range at available frequency rates between 0.1 and 999 Hz.
In addition, we have combined the new EST with local anesthetic injections (bupivacaine 0.25%) with clinical success. This technique provides a combined (electrical and chemical) nerve block that enhances treatment of a neuropathy or a painful condition (see Tables 1 and 2). According to the Gould Medical
Dictionary, a nerve block is defined as “[t]he interruption of the passage of impulses through a nerve, as by chemical, mechanical, or electrical means.” Because nerve blocks occur at voltage-gated channels, all nerve blocks are essentially electrical. According to Szasz, “There is no such thing as a chemical block … only an electrical block.”6 We refer to this as combined electrochemical block (CEB).
It is the experience of the authors that pain is reduced by CEB in about 80% of patients who have neuropathies. As shown in Figure 1, 16 patients with neuropathies improved over a course of 20 treatments. The CEB also has worked well in many cases of failed spine fusion syndrome and failed back surgery syndrome. In a small series of patients, more than 50% of those with hardware and intractable pain and proprioception difficulties showed improvement with bilateral transforminal epidural bupivacaine injections along with the application of EST.7 In fact, CEB may be considered a less invasive alternative to spinal cord stimulator implantation.
A 73-year-old woman had a 15-year history of low back pain with pain radiation down the legs. Diagnostic studies revealed spinal stenosis and facet arthropathy. She received three CEBs and two ESTs weekly for 3 weeks. After a pause of several days, she received two CEBs and three EST treatments over 2 weeks. At the end of this time, her visual analogue scale pain score had dropped from 10 of 10 to 2 of 10, and she was able to leave her house and walk with her husband.
Electromagnetic Physics of the Body
Why does this work? One major difference between the electric cell-signaling currents in EST and older devices is that EST allows greater depth of penetration through the dermal tissue by overall lowering of impedance to higher-frequency currents. This unique multiplex signaling configuration of mixed higher MF with overriding lower stimulatory frequencies (combined FM and AM signals) allows for the optimum voltage necessary to achieve proper depth of penetration while using lowered therapeutic response frequencies to affect the voltage-gated channels and receptors within target tissue (see Table 2).
By continually varying the primary medium frequency or using the frequency-modulated signals in a higher range, we can overcome the natural resistance to different tissue structures. Examples of these different resistant values are typically measured in ohms. The lowest resistance (impedance) is, in fact, neural tissue (1,000 Ω), so most (>65%) of the current (energy) will be drawn to the nerves.
Stimulatory effects are defined as the physiologic effects that appear from the use of lower electric current frequencies, which produce repeated action potentials (impulses) in excitable cells (LF). The induced membrane depolarization and subsequent repolarization produce a number of mechanisms of action known to be effective in treatment by varying the stimulation frequency. These include analgesia from the principle of counter-irritation; analgesia from stimulated neuropeptide release (eg, β-endorphin, encephalin); enhanced circulation; sympathetically mediated vasoconstriction (detumescence effects); sympathetically mediated vasodilatation (antispasmodic effects); muscle activation, training, and strengthening; excitation of sprouting nerve axon processes; and an overall influence on the metabolism.8-12
Facilitatory effects are defined as the varied and multiple physiologic effects (biochemical changes) that appear from the use of higher MF electric currents directly or indirectly, but not occurring from the repeated production of any action potentials. There are a number of physiologic changes and biochemical actions that can be seen from the use of these higher MF signals and their resonance components. Examples include analgesia from balancing the metabolite concentration differences (pH); analgesia from second-messenger formation (cyclic AMP [cAMP]-mediated membrane repair processes); analgesia from nerve (pain) fiber blockade via reactive depolarization; vessel vasoconstriction via contraction of the vessel wall smooth muscle; anti-inflammatory activity by activating filtration/diffusion processes;11 edema management, activation of regeneration and support by second messenger formation (eg, cAMP); immune system activation and support via improved intercellular communication; and the general facilitation of metabolism.11-14