Neuropathy And Electro Stimulation Part 1

Today's post from absolutept.com (see link below) is the first of 4 looking at the qualities and effectiveness of EMS or Tens units in helping reduce neuropathic symptoms. Not all experts are fans of TENS systems, or believe that electro-stimulation is beneficial to neuropathy patients but as with so many of these things in the neuropathy world; they work for many people and bring relief, so deserve to be taken seriously. The problem may be that to get treatment in this area, many people have to go to private clinics and pay outside their normal insurance and that immediately raises the spectre of rampant commercialism and leads people to suspect they're going to be ripped off. This blog doesn't normally advertise but when someone provides useful and fact based information, which is of benefit to everyone considering their treatment options, then there is no objection to highlighting a medical facility. That's the case here. Chad Reilly (sports physical therapist) provides such a comprehensive analysis of EMS/TENS that patients may wish to take it further, either with him or their local TENS provider. Definitely worth reading if you want to know more about how it all works. All four sections appear within these four days.

Electric Stimulation and Neuropathy (Part 1)

Chad's Physical Therapy Blog - Chad Reilly

I’ve have to admit I have never been very interested in neuropathy because as a physical therapist it was never something I could do anything about. However, as a former weightlifter I have always been very interested in strength, and increasing strength does a great job improving balance and decreasing fall risk in a number of my patients. Those patients it turns out very often have neuropathy and until 2013 I thought neuropathy was just something we had to accept, work around do our best to compensate for.

However in 2011 I read the Charlie Francis Training System, which was a book about coaching sprinters and it had a chapter on electric muscle stimulation for both injury recovery and increasing strength. Some time after that I had a runner friend report she used one of the newer-fangled EMS/TENS units, with results I thought had to be psychological. However, that got me looking more into it, and it turns out according to literally hundreds of new studies it works a lot better than placebo. So by 2013 I was very interested in electric stimulation and the capabilities of newer, better, and best of all, less expensive machines.

About that time I had patient I was seeing for a total hip replacement, but the muscles around his ankle were extremely weak from neuropathy. Exercise alone was getting such a weak contraction that there was little chance for it to result in any muscular hypertrophy or strengthening. So I thought this is where electric muscle stimulation could be a big help, and sure enough it was. I started using it on the the feet and hands of my patients with neuropathy and universally they all loved it. They reporting it made their feet and hands feel better, decreasing pain, decreasing tingling and increasing strength. Also with long term home use at least one patient I have is noting increased sensation in his hands measured with Semmes Weinstein monofilament testing.

So I did a literature review on electric stimulation and neuropathy and found I wasn’t the first to make the connection. I found several studies already showing significant and substantial improvement in peoples’ condition with electric stimulation. I thought each study would be worth a blog of its own discussing the patients types, the electrical stimulation parameters used, and the results they found. I figure this will better optimize my own treatment protocols which I plan to put together in a case study, case series, and later randomized controlled trial to see exactly what electric stimulation can achieve in the treatment of neuropathy. It was a circuitous route that got me here, but as my blog posts will show it’s certainly an area of interest for me now.

That said, here’s the first study I came across:

Diabetic peripheral neuropathy: amelioration of pain with transcutaneous electrostimulation. Diabetes Care. 1997 Nov;20(11):1702-5. Kumar D, Marshall HJ.


Abstract
OBJECTIVE:
 
To evaluate the efficacy of transcutaneous electrotherapy for chronic painful peripheral neuropathy in patients with type 2 diabetes.
RESEARCH DESIGN AND METHODS:
Thirty-one patients with symptoms and signs of peripheral neuropathy were randomized to the electrotherapy or sham treatment (control) group. The electrostimulation was given by a portable unit (H-Wave machine) than generated a biphasic, exponentially decaying waveform (pulse width 4 ms, 25-35 V, and gt; or = 2 Hz). Patients treated each of their lower extremities for 30 min daily for 4 weeks at home. Nine patients from the sham-treatment group participated for a second period, during which all of them received the active electrotherapy. Patient’s degree of pain and discomfort was graded on a scale of 0 to 5.

RESULTS:
In the sham-treated group (n = 13), the neuropathic symptoms improved in five (38%) patients, and the pain score declined from 2.92 +/- 0.13 to 2.38 +/- 0.26 (P and lt; 0.04), suggesting a procedure-related placebo effect. In the electrotherapy group (n = 18), symptomatic improvement was seen in 15 (83%) cases, 3 of which were completely asymptomatic; the pain score declined from 3.17 +/- 0.12 to 1.44 +/- 0.25 (P and lt; 0.01) and the posttreatment pain scores were considerably lower (P and lt; 0.03), indicating a substantial treatment effect over and above any placebo influence. Patients in the electrotherapy group reported greater reduction in symptoms (52 +/- 7% vs. 27 +/- 10% in control subjects, P and lt; 0.05) on an analog scale. Moreover, the electrotherapy decreased pain scores (from 3.0 +/- 0.62 to 1.56 +/- 0.32, P and lt; 0.02) in nine patients who had received sham treatment earlier.

CONCLUSIONS:
A form of transcutaneous electrotherapy ameliorated the pain and discomfort associated with peripheral neuropathy. This novel modality offers a potential non-pharmacological treatment option.

My comments:

This study didn’t look at function but rather attempted to lessen/eliminate pain in patients with the painful form of neuropathy (some patients don’t hurt but only have numbness). As noted in the abstract, 83% of those treated with electric stimulation improved and 17% became completely asymptomatic.

Parameters used in the study were:
Waveform: biphasic exponentially decaying
Duty Cycle: continuous (I think)

Pulse Duration: 400 uS
Intensity: 35 mA (max)
Rate: user adjustable from 2-70 Hz
Treatment Length: 30 minutes
Training Frequency: Daily
Training Length: 4 weeks
Electrodes: 4 electrodes; 2 placed on the distal quadriceps, 1 on the neck of the fibula and 1 centered gastrocnemius muscle (size not given)

My treatments are shorter in duration using biphasic square waveforms and EMS patterns designed to increase strength, but my patients report pain relief similar to the above researchers. The reason I use the EMS strength protocols is because they have been found to be better than TENS at decreasing pain. For neuropathy, I really want to try to not just decrease pain but also increase muscle mass to help with function, to elicit strong muscle contractions, and to pump blood into the area in an attempt to improve circulation. I think all of these things should help with neuropathic pain. Also I use 4 large electrodes (4” circular) and right now prefer to place 2 on the gastrocnemius, 1 on the tibialis anterior, and 1 on the sole of the foot. One thing I notice with my lower extremity neuropathy patients is they often need an especially strong stimulator to get a good muscle contraction. The 35 mA used in this study I expect will decrease pain, but I think they would get better results if they increased their pulse width to 450 mA, and intensity as tolerated up to around 60-70 mA. Also while I have not tried it yet, I suspect an ideal EMS program would not be just one set of parameters, but rather alternate between 2 or more, with some settings directed at increasing strength, and with others directed more towards improving circulation and cardiovascular benefits.

The study was only 30 days long, and while my patients usually report immediate relief ongoing treatment seems to continually lessen symptoms. My patient who I am following with regards to increased sensation has been doing the electric stimulation at home every other day for 3 months, and we plan to retest going forward. So I do think home use of a stimulator is ideal because they often pay for themselves quickly and ideal use I would expect to be at least 3 times per week if not daily. So while I frequently do the treatment in my office, a lot of what I do is help patients decide what kind of EMS/TENS machine and accessories they need, help them program the machine, and teach them how to set up the electrodes for home use.

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