Sharing Mayo Clinic: Neurostimulation stops pain signals in their tracks

Sharing Mayo Clinic: Neurostimulation stops pain signals in their tracks

By
Dana Sparks

June 2, 2019

Unrelenting foot pain dictated Valerie Nicolaison's life for years. It eventually took away her ability to drive, cook, walk and stand. In 2018, however, Valerie's pain met its match when she received a device that stops pain signals in their tracks.

There was a time in her life that Valerie Nicolaison didn't think she would ever be able to take her Chihuahua, Colt, for a walk. Day in and day out for more than seven years, Valerie lived with foot pain so intense that it hobbled her. She couldn't wear shoes. Socks were problematic. Even soft sensations, like a sheet on her feet in bed, shot jolts of electric pain up her legs and through her body.

In fall 2018, however, Valerie's life underwent a dramatic transformation when she was implanted with a dorsal root ganglion stimulator at Mayo Clinic. The device blocks the pain signals moving from Valerie's feet to her brain, and it has opened up her life to a world of shoes, outings and new possibilities.

"I can take Colt on short walks now, which feels pretty amazing," Valerie says. "It's definitely still a work in progress, but I am able to do so many things now that I wasn't sure I would do again. And I know it's only going to get better."

Although spinal cord stimulators have been available for about 30 years for chronic back and leg pain, the devices have been much less effective for foot pain. Mayo Clinic was one of the first medical centers in the U.S. to offer patients dorsal root ganglion, or DRG, stimulation, says Valerie's physician Tim Lamer, M.D., in Pain Medicine.

"The problem with the traditional spinal cord stimulator is while they do a good job of covering pain in the legs and lower back, they don't do as good a job of covering pain in the feet," Dr. Lamer says. "DRG is a honed electrical signal to a specific area."

An arduous journey

Valerie's struggle with foot pain began in 1999 when she was 24. The pain set in gradually. Eventually, it became so severe that it prevented her from walking or driving. Valerie, who at the time lived in Staples, Minnesota, was diagnosed with Morton's neuroma — a thickening of the tissue around the nerves leading to the toes. In 2001, the abnormal tissues were surgically removed. After that, her pain subsided.

But one morning in November 2011, Valerie woke up, and the pain was back. "It was overnight. I was not able to walk," Valerie says. "My feet just constantly wanted to cramp. All the way through my toes and arches, just all at once. It was pressure that just did not let up."

Valerie's surgeon determined the Morton's neuroma had caused additional growths to develop.

"Seven more tumors were removed from both feet, which gave me a little bit of relief," Valerie says. "But the pain still always came back."

"I could not sit with my feet down on the floor like a normal person. I'd have to have them propped up on something."
Valerie Nicolaison

Valerie was referred to a larger medical center in the Twin Cities for testing. "Everything on the planet was ruled out," she says, explaining that she was examined by neurologists, oncologists, rheumatologists, vascular surgeons and other specialists.

Valerie, an accountant, tried to work around her painful symptoms, but eventually was forced to go on unpaid medical leave. "I could not sit with my feet down on the floor like a normal person. I'd have to have them propped up on something," she says. "At work in meetings, I would have to find another chair to bring over."

Temperature also affected Valerie's pain. When her feet got cold, as they often did in Minnesota, the pain got worse. The impact of the cold temperatures on her painful condition prompted her and her husband, Chad, to recently move to Arizona.

Through the years, Valerie tried a number of pain management strategies, including injections, acupuncture, mirror therapy, physical therapy, transcutaneous electrical stimulation and biofeedback. None of them worked.

In 2018, Valerie started working with a pain management specialist in Duluth, Minnesota, who diagnosed her with complex regional pain syndrome, or CRPS. In addition to a new diagnosis, the pain specialist provided Valerie with a referral to Dr. Lamer.

An alternate treatment route

During her first appointment at Mayo Clinic's Rochester campus, Valerie detailed her history and symptoms to Dr. Lamer. "Dr. Lamer looked at my feet and really listened to my story," Valerie says. "That was one thing that impressed me. I felt like he was there to listen to everything I had to say and get all of the information that he needed to help me."

While complex regional pain syndrome is not a common condition, it can be debilitating to those it affects, Dr. Lamer says. "The word 'complex' is there for a reason. It's a chronic pain condition almost always affecting an arm or leg or foot or hand, and it almost always occurs after trauma."

The trauma could be as slight as an ankle sprain or intense as a surgical procedure, Dr. Lamer explains. "And what happens is instead of the nerves in the affected limb healing normally, they never really get back to normal and remain in a constant state of overdrive."

In extreme cases, nearly everything the limb is exposed to causes pain. For Valerie, even the slightest touch was unbearable. "Valerie came into my office in the middle of winter with sandals on," Dr. Lamer says. "If her dog steps on her foot, it sends her through the roof. It was literally debilitating her. She was basically housebound."

For patients like Valerie, whose pain is unresponsive to other treatment, dorsal root ganglion stimulation, can be life-changing. The device consists of electrical leads that run from a battery and are surgically placed directly next to the dorsal root ganglion — one of the control centers for nerves coming into the spinal cord. When the device is activated, an electrical current is generated and sent to the dorsal root ganglion, where it intercepts the pain signals coming from the affected limb.

A huge step forward

For all the relief the device could possibly give her, Valerie says she was petrified of the surgery. "There weren't many stops after this if it didn't work," Valerie says. "Dr. Lamer knew that, and he was very calming and reassuring."

During the outpatient operation in October 2018, the leads and battery pack were implanted into Valerie's lower back. When she woke up, a staff member with expertise in device programming was present, ready to turn on and fine-tune the device.

"The relief wasn't immediate, but it was pretty quick," Valerie says. A few hours after the device was activated, Valerie was discharged from the hospital.

"This is like night and day for me. I really feel like I've been given my life back."
Valerie Nicolaison

The current from the device is sent continuously, but should Valerie want to stop the electrical signals, she can control the device from an iPod. She will return to Mayo Clinic every few years to have the device's battery pack replaced. Barring unexpected issues, Valerie's foot pain should continue to improve, Dr. Lamer says.

"I got so used to the 24/7 pain that it just became my new normal," Valerie says. "Before, if I wanted to do anything, it had to be right away in the morning. And now, I can actually go play pool in the evenings. I never thought I'd be able to go do something in the evening ever again. This is like night and day for me. I really feel like I've been given my life back."

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