Electric Muscle Stimulation Better than TENS for Neuropathy

Effective treatment of symptomatic diabetic polyneuropathy by high-frequency external muscle stimulation. Diabetologia. 2005 May;48(5):824-8.  Reichstein L, Labrenz S, Ziegler D, Martin S.

Abstract
AIMS/HYPOTHESIS:
Diabetic distal symmetrical sensory polyneuropathy (DSP) affects 20-30% of diabetic patients. Transcutaneous electrical nerve stimulation (TENS) and electrical spinal cord stimulation have been proposed as physical therapies. We performed a controlled, randomised pilot trial to compare the effects of high-frequency external muscle stimulation (HF) with those of TENS in patients with symptomatic DSP.

 
METHODS:
Patients with type 2 diabetes and DSP (n=41) were randomised to receive treatment with TENS or HF using strata for non-painful (n=20) and painful sensory symptoms (n=21). Both lower extremities were treated for 30 min daily for three consecutive days. The patients’ degree of symptoms and pain were graded daily on a scale of one to ten, before, during and 2 days after treatment termination. Responders were defined by the alleviation of one or more symptoms by at least three points.

 
RESULTS:
The two treatment groups were similar in terms of baseline characteristics, such as age, duration of diabetes, neurological symptoms scores and neurological disability scores. The responder rate was significantly higher (p<0.05) in the HF group (80%, 16 out of 20) than in the TENS group (33%, seven out of 21). Subgroup analysis revealed that HF was more effective than TENS in relieving the symptoms of non-painful neuropathy (HF: 100%, seven out of seven; TENS: 44%, four out of nine; p<0.05) and painful neuropathy (HF: 69%, nine out of 13; TENS: 25%, three out of 12; p<0.05). The responders did not differ in terms of the reduction in mean symptom intensity during the trial.

 
CONCLUSIONS/INTERPRETATION:
This pilot study shows, for the first time, that HF can ameliorate the discomfort and pain associated with DSP, and suggests that HF is more effective than TENS. External muscle stimulation offers a new therapeutic option for DSP.

My comments:

I would have really liked this study had it shown great results with the high frequency (HF) electric stimulation, and compared it to TENS and found the HF worked considerably better. The next study I am going to cite uses the exact same HF machine and calls it EMS (electric muscle stimulation) rather than HF, and that fits with my observations and other research that EMS works better than TENS to control pain.

What I don’t like about this study, however, is that from the description of the parameters I can’t figure out what they used. Plus, other things besides the current are different, including electrode size and placement.

For the TENS group I get:

  • Waveform: biphasic exponentially decaying
  • Duty Cycle: continuous (I think)
  • Pulse Duration: 400 uS
  • Intensity: 20-30 mA
  • Rate: 180 Hz
  • Treatment Length: 30 min
  • Training Frequency: daily
  • Training Length: 3 days
  • Electrodes: two sticky ~2” electrodes per leg, placed on proximal and distal fibula region

For the HS group:

  • Waveform: biphasic exponentially decaying
  • Duty Cycle: 3 sec ramp, 3 sec on (3 sec off I think, because that’s what the next study using the same machine reports)
  • Pulse Duration: does not say but with the high Hz I expect its pretty short
  • Intensity: adjusted to a pleasant level without pain or uncomfortable paresthesia
  • Rate: 4096 Hz – 32768
  • Treatment Length: 30 min
  • Training Frequency: daily
  • Training Length: 3 days
  • Electrodes: two carbon ~3.5” rubber carbon electrodes per leg, placed on the proximal and distal quadriceps.

So in this study the HS group did a lot better, but it is hard to tell if it is due to the difference in current, or the larger electrodes being used in the HS group, or the HS group putting the electrodes over a muscle rather than a bony region. I would expect the larger electrodes to work better because you can turn the machine up higher with greater patient comfort because of lesser current density (coulumbs delivered per square inch of skin). Also I don’t think it’s at all ideal to place the smaller electrodes over the bony region of the fibula, though I find it interesting that the larger electrodes on the quadriceps worked so well since presumably the diabetic neuropathy sufferers were complaining of the most pain and paresthesias in the feet. Another interesting thing is the good results of the HS group was noticed in just 3 days of treatment, which is in accordance with my observation using EMS. My patients report relief immediately after my 12 minute treatment, and those results continue to improve with future treatments. Also interesting from this study is they treated people with both painful and non painful neuropathy, noting it worked on non-painful neuropathy better. My patients tend to report similar improvements painful or not with my protocol, but that could be due to the different parameters where I’m using 4 electrodes per leg instead of two, placing all the electrodes on muscle (including the bottom of the foot), my electrodes are larger still, and I use as long a pulse width as my machines allow (300-450 uS) for as high an intensity as they can tolerate.  

So the take home message for me is that all stimulation parameters are not equal, but in this study it is unclear which part of the different stimulation protocols led to the difference in effects. I suspect that greater intensity of stimulation, and on and off period, larger electrodes, placing the electrodes over muscle all contributed to better outcomes in the latter group.  

Thanks for reading my blog. If you have any questions or comments (even hostile ones) please don’t hesitate to ask/share. If you’re reading one of my older blogs, perhaps unrelated to neck or back pain, and it helps you, please remember SpineFit Yoga for you or someone you know in the future.


Chad Reilly is a Physical Therapist, obtaining his Master’s in Physical Therapy from Northern Arizona University. He graduated Summa Cum Laude with a B.S. Exercise Science also from NAU. He is a Certified Strength and Conditioning Specialist, and holds a USA Weightlifting Club Coach Certification as well as a NASM Personal Training Certificate. Chad completed his Yoga Teacher Training at Sampoorna Yoga in Goa, India.


Comments

2 responses to “Electric Muscle Stimulation Better than TENS for Neuropathy”

  1. JEFF WISDOM

    I have idiopathic peripheral neuropathy and no TENS therapy I’ve used helped at all. I’m currently trying an EMS footpad which seems to provide a pretty strong jolt and contraction of muscles in the feet, ankles and calves.

    I’m using it daily for 30 minutes and I must say I’m cautiously optimistic about the results so far. I definitely notice great improvement after a long walk or jog (several miles), but the pain returns in a few days. The only problem is I don’t have time for that on a regular basis, so I’m using the EMS treatments. I can only speculate that the EMS mimics the exercise by temporarily restoring transmission through damaged nerve synapses. If only it could be permanent : ( .

    1. Chad Reilly

      Hi Jeff,

      I have a few comments.

      For neuropathy I agree most TENS probably doesn’t do much if anything. With the nerves being weakened the current needs to be very strong. EMS being better than TENS because EMS is usually stronger. I was getting really good results with my people with just 10 minutes per day, but I think there is good reason for optimism. However, I’ve learned some things that might help more, particularly for neuropathy.

      First, when stimulating my feet regularly to build up my arch support after what I think was the start of a stress fracture a couple years ago in my foot. Instead of standing on the pads, using two channels, one per foot, I now use just one channel and strap one pad to the bottom of each foot while I sit and read a book. My feet cramp, but I’ve just gotten used to that, but by dividing the channel, one side per leg the electrodes are so far from each other that it makes the stimulation go deeper. I can feel the stimulation up to and above my knees, which I think would be ideal for neuropathy.

      Second, I did a blog on aerobic TENS somewhere on here where I determined 5 hz was ideal for increasing blood flow, so now I’ll don 10-50-10, or 5-15-10 for strength with EMS, but my Globus (you need a programmable medical Genesy or european Triathlon, that you can order from Italy off ebay to get one that’s “programmable”) will leg my program 5 hz TENS during the “rest” periods of the EMS blasts. So I’m getting strength and cardio at the same time. I would think for neuropathy this would be perfect as the EMS would increase muscle hypertrophy of the feet, so there’s something to pump blood too, while the aerobic TENS would flush the area with blood.

      Third I would absolutely read my blogs on fasting, as there is research to suggest intermittent fasting helps with the healing of neurons, including peripheral neurons via autophagy. Plus any weight loss would lessen systemic inflammation, blood sugar, and blood cholesterol, all of which are very likely causes for neuropathy.

      Finally. I wrote these articles originally for my physical therapy website, before spinal flow was created, but I think my SpineFit Yoga, would be helpful in that the SF5 flow is only 5 minutes long, builds muscle below the knee, and really seems to have a cardiovascular effects. My resting heart rate now is in the 30s. Which I think is a combination of the my intermittent fasting and SF5.

      All told that might get you more lasting relief, though I expect it’s all to a degree “use it or lose it.”

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