External electric muscle stimulation improves burning sensations and sleeping disturbances in patients with type 2 diabetes and symptomatic neuropathy. (2009)

OBJECTIVE:
External muscle stimulation (EMS) of the thighs was previously shown to have beneficial effects in a pilot study on painful diabetic neuropathy. However, differential effects on specific symptoms of neuropathy as well as determinants of treatment response have not been described.

DESIGN:
Ninety-two type 2 diabetes patients with different neuropathic symptoms were included in a prospective uncontrolled trial. Patients were treated twice a week for 4 weeks. Symptoms were graded on numeric scales at baseline, before the second and the eighth visit.

RESULTS:
Seventy-three percent of the participants reported marked improvement of symptoms. Subjective treatment response was positively and independently associated with symptom intensity but independent of disease extent, metabolic factors, age, or gender. Total symptoms graded by patients on numerical scales decreased significantly after 4 weeks of treatment. Patients in the upper tertile of symptom intensity showed significant improvement of paresthesia, pain, numbness and most pronounced for burning sensations and sleeping disturbances.

CONCLUSIONS:
In an uncontrolled setting, EMS seems to be an effective treatment for symptomatic neuropathy in patients with type 2 diabetes, especially in patients with strong symptoms.

 

Parameters:

• Waveform: biphasic sinusoidal
• Duty Cycle: 3s ramp, 3 on,
• Pulse Duration: ?
• Intensity: tolerable but not painful muscle contraction
• Rate: 20 Hz frequency scanner of 4096-32768 Hz
• Treatment Length: 60 minutes
• Training Frequency: 2x/week
• Training Length: 4 weeks
• Electrodes/Placement: two electrodes per leg placed on the quadriceps

My comments:
This study is interesting because it broke down symptom improvement to include paresthesias, pain, burning sensation, sleep disturbance and numbness. However all of these improvements were based on patient reports, which is good, but as of yet nobody that I am aware of has objectively tested sensation to see if it changes. They noted improvement after the 2nd treatment and greater improvement after the 8th. Symptom reduction was consistent, but less than reported in prior studies. I would expect better improvements with daily or every other day stimulation (as the prior study seems to have had greater results with just 3 treatments on consecutive days) so I think portable but strong electric muscle stimulators patients can use at home would have led to a better outcome.  Also, treatment duration of 60 minutes does not seem to work any better than 30 minutes. Additionally, anecdotal evidence from my office is that just 12 minutes works pretty well, but I’m using a greater intensity of electric stimulation, with electrode pad placement directly over muscles in the painful/numb regions.

So my take home message from this study is daily stimulation is probably better than 2 times per week, and a really good study would be to objectively test sensation before and after a trail of EMS to see if lost sensation can be restored along with subjective reductions in pain and paresthesias.