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February 19, 2015

Breaking Away From Pain With the Help of ‘The Scrambler’

By Hoyt Finnamore

KarenSafranek1000Participating in a clinical trial gave Karen Safranek a solution to her decade-long struggle with peripheral neuropathy 

Karen Safranek didn't take a worry-free step for 10 years. Severe peripheral neuropathy — a side effect of breast cancer treatment she received in 2002 — left her with constant burning, tingling, numbness and pain in both her feet.

Over time, Karen tried dozens of treatments to rid herself of the discomfort. Nothing worked. So in 2012 when she found out about a clinical research trial available at Mayo Clinic for people who had peripheral neuropathy after chemotherapy, she was interested, but not optimistic.

"I tried so many things. Anything a doctor recommended or heard about, or anything I heard about, I'd give it a try if I could," Karen says. "But years past, and the pain didn't get any better. By 2011, life was not good. I was analyzing my house to figure out where we could put a wheelchair ramp. At that time, I thought it wouldn't be much longer before I couldn't walk anymore." 

This new treatment was different. With MC-5A Calmare Therapy, often called "the scrambler" for short, Karen noticed improvement following the first session. After completing a series of treatments, she was pain-free for the first time in more than a decade. Through her participation in the clinical trial and occasional follow-up treatments at Mayo Clinic, Karen has been able to leave peripheral neuropathy behind and reclaim her life.

Battling pervasive pain

Karen began to notice symptoms of peripheral neuropathy shortly after she started receiving chemotherapy. By the end of her treatments, her breast cancer was gone, but she had constant shooting pain and numbness in her feet and legs that left her weak and unable to maintain her balance.

Peripheral neuropathy is a common side effect of some chemotherapy drugs. For many people, the condition fades away after treatment is over. But for some, like Karen, it can last long after other chemo side effects are gone and can have a significant impact on day-to-day life. The effect on Karen's life was overwhelming.

"It hurt if I was sitting, walking or standing," she says. "Blankets hurt my legs. I wasn't getting a good night's sleep. Going back to work wasn't an option. In time, it got so bad that whenever I went somewhere, I would analyze where I had to park my car and how far it was to get to the building. If there wasn't a spot close enough for me to walk the distance to and from my car, I would just go home."

Retraining the brain

Traditionally, chronic peripheral neuropathy has been challenging to successfully treat. Like many others who have this debilitating disorder, Karen tried everything she and her doctors could think of to relieve her pain. But still she suffered. Then in December 2013, Karen learned of the clinical trial at Mayo Clinic that would change everything for her.

Peripheral neuropathy happens as a result of nerve damage. The damaged nerves send aberrant signals to the brain, causing pain and the other symptoms of peripheral neuropathy. During her treatment sessions as a participant in the research study, the damaged nerves in Karen's feet were connected by electrodes to the scrambler. The device sent painless electrical signals to the damaged nerves, and the nerves relayed those signals to the brain. The new signals broke the pain cycle by retraining Karen's brain to understand that it was not really experiencing pain.

Reclaiming her life

Although the scrambler does not ease symptoms of peripheral neuropathy in all cases, Karen's response was dramatic.

"I was tremendously better after just one treatment," she says. "My feet and legs felt light and pain-free. Previously, I had felt as though they were very heavy to lift and walking was comparable to wearing cement shoes. After the treatment, I could walk really fast. I could take the stairs. I could even run."

After a total of 10 treatment sessions in January 2013, Karen no longer had any symptoms. The effects of the treatment were not permanent, however. She returned to Mayo Clinic for additional scrambler treatment nine months after her first sessions and again eight months after that.

Even though she knows she'll likely need follow-up care over the long-term to keep peripheral neuropathy at bay, Karen is enthusiastic about the difference the treatment has made for her.

"Before this, I wasn't able to do some of the smallest things. I couldn't go grocery shopping alone. If I reached up to take an item off the shelf, I'd lose my balance and tip over. I couldn't walk on uneven ground because I couldn't feel my feet. I'd just fall down," she says. "Being able to participate in this clinical trial at Mayo Clinic with the scrambler, it brought my life back to me. It's a miracle. It really is."

In the video below, Karen and her doctor, Charles Loprinzi, M.D., describe her experience in a Reuters news story.



Tags: breast cancer, Cancer, Mayo Clinic Cancer Center, Peripheral Neuropathy, Rochester Campus

The MC5-A Calmare therapy device is designed to generate a patient-specific cutaneous electrostimulation to reduce the abnormal pain intensity. Sixteen patients from one center received one-hour interventions daily over 10 working days.


Hi Christa;
Does scrambler work on hands and arms also. My pain is in legs and arms and feet and hands


Also is it covered by insurance


I am willing to bet that I am at the edge of going crazy and have tried everything for my SEVERE peripheral Neuropathy (chemo induced). I had read of the Mayo clinic trial but never saw any results until now. So…… where do I get the Calmare scrambler treatments in the Southern California! I am hoping that I might soon no longer wake up in tears from the pain. Has it been approved for insurance payment (I don’t really care , if it works).


Hi Janlynne: How are you? Were you able to receive the treatments. Did it work for you.


I just joined after nearly 20 years of PN. I was in peak physical condition when mine hit out of the blue in 1997. First symptoms were numbness, fleeting limb weakness, neurogenic bladder and inorgasmia. As the pain became worse and my limbs felt weaker I stopped exercising. Then I hit menopause so now I’m overweight, glucose intolerant (all which make things worse) and suffering daily. I work from home (which is becoming difficult) and feel my life’s over at 52. I’m hoping I can find some helpful info on this site.


OMG! I couldn’t believe what I was reading! I have suffered with this peripheral neuropathy for so long. When I try to describe what’s going on with me to my family, they have no clue what I’m talking about. Some say, “how can you have numb legs but then they hurt on the inside? I thought if they were numb, you didn’t feel anything.” All of these posted symptoms are exactly like mine – the pain, legs feleling like they are cement, total loss of balance. My many doctors call it “idiopathic” and say there is no cure and it will only get worse and travel up my arms. I am so excited there may be some relief.


Severe PN had symptoms but idk it was PN. Then, sudden onset due to prolonged B vitamin deficiency, autoimmune dx and medication. I alxo underwent a gastric sleeve procedure which made me unable to consume enough nurishment to endure the harsh effects of mefication. Admitted to hospital with severe malnutrition, extremely low sugat and blood pressure as well as pancreatitus, gall bladder obstruction and inflamed liver.
I am now experiencing symptoms of fasciculstion. I am unable to work and have strong desire to overcome this condition.
Currently I had 43 great days with minimal symptoms, past 5 days have not been great.


Not sure if what I have can relate to some, but trying anyway in hopes that someone at the Mayo Clinic will read an respond. I also had cancer 5 years ago this was treated an so far cured through surgery with Cemo/radiation not required. 10 months ago I went to Costa Rica shortly after caught a virus or something that went away. 2 weeks later I wake up with both feet an ankles number & tingling.
Doctors say neuropathy take a pill for your symptoms which are of course anti depressants.

Jump forward after 4 months treatment to help cure neuropathy through infrared an laser treatment maybe it’s not neuropathy at all?? At least there is no consistent evidence to prove to insurance companies!

Best I can figure is they just are looking hard enough to find out why this occurs in some an not others?

Feet are now so numb I can’t feel the break or gas peddle so disability really in my future???

I get out of bed every morning stomp my feet and say wake up!!! It never works:)

Thanks for listening


If you would like to seek help from Mayo Clinic, please call one of our appointment offices (Arizona: 480-301-1735 Florida: 904-953-0853 Minnesota: 507-284-2511). You might also consider visiting Mayo Clinic Connect (, where you can communicate with other patients who may have had similar experiences.


Are there devices available for home use that work?

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