What Absence Feels Like

New therapies give hope to amputees experiencing the common phenomenon of 'phantom pain'

By Gary Goettling

hull

A LOT OF NERVE: Losing an arm didn’t stop fire department veteran Eugene Hull from continuing to serve. Now new treatments are helping him fight residual pain.

Kay Hinton

Eugene Hull still feels sensation in his right arm, even though cancer forced its amputation at the shoulder, along with a portion of collarbone, nine years ago. Not long after surgery, the fifty-three-year-old father of three began experiencing “phantom pain” in his absent limb. He describes the feeling as a “tingling like needles” similar to what people mean when they say their foot or arm has fallen asleep.

“That’s a constant,” says the thirty-four-year veteran of the Columbus Department of Fire and EMS, who attained the rank of lieutenant as a firefighter and now works as a training officer. “But every two or three weeks I would get sharp jolts of pain that radiated up my fingers and into my shoulders. I described it one time as like sticking a hot wire up my arm and shooting electricity through it. At times you couldn’t get a whole lot done because it was so debilitating.”

He discovered an interesting trick with his left hand: Rubbing the back of his thumb with his forefinger stopped the pain, “but as soon as I quit, it came back. Anyway, you can’t rub the back of your thumb all day long.”

Hull’s orthopedic surgeon recently read about clinical studies on alleviating phantom pain conducted by J. David Prologo, an assistant professor and interventional radiologist at the School of Medicine. For the past decade, Prologo has worked with cryonic techniques to mitigate the severe, difficult-to-treat pain accompanying heart disease, cancer, and other conditions. More recently, his attention has turned to applying the procedures to the phantom pain frequently experienced by amputees.

“For a long time, people studied whether or not these feelings are initiated in your brain or initiated peripherally,” Prologo says. “Then evidence started to suggest that you could get some pain relief if you could shut down the nerve peripherally.”

When an appendage is amputated, whether by trauma or surgery, the nerve is cut. Scar tissue called neuroma forms at the end of the damaged nerve. “It’s not normal tissue, but it sends false signals to the brain about the missing arm or leg, producing phantom pain,” Prologo explains.

To stop the symptoms, Prologo uses a technique called cryoablation therapy. First, the severed nerve is identified and located by sonogram or CT scan. Nerves in the human body serve very defined areas, Prologo notes, so symptoms are specific to certain nerves. In most situations it’s just one nerve producing phantom pain; it’s usually not more than two. Then a cryoprobe is inserted through the skin precisely at the neuroma site and left in place for twenty-five minutes as it lowers the neuroma’s temperature to freezing, creating an ablation zone and effectively shutting down nerve transmissions. The entire process takes about an hour and is performed on an outpatient basis.

Cryoablation therapy to extirpate pain in non-amputee situations has provided significant relief for up to a year in 90 percent of his patients, Prologo says. It’s still too early to know what kind of long-term results can be expected for amputees, which is why more clinical trials are necessary.

Hull contacted Prologo and underwent the procedure this past May. Except for some discomfort caused by swelling around the ablation site, it went well.

“I’m feeling optimistic,” Hull says. “Dr. Prologo is very positive with everything, so I’ve got a lot of faith in him.” 

Hull has since reported positive results from the procedure.

He can also take heart from the example of Joan Burton. Complications from diabetes forced the amputation of her right leg above the knee nearly six years ago. 

“The phantom pains started about three or four months after the surgery,” says Burton, seventy-five, a great-grandmother and retired educator. “I was not aware of what was causing the pain because it was in a limb that no longer existed, so it was very confusing for me to understand what was going on.”

Over the years, “the pain would come and go, but finally at one point its ferocity became more than I could bear,” she continues. “I was grinding my teeth and having an enormous amount of difficulty, and that’s when I was referred to Dr. Prologo.”

Following cryoablation therapy, she was pain free for six or seven months, until symptoms resurfaced, but from a different nerve affecting a different part of her missing leg and foot. A second treatment brought improvement.

“Once in a while I get a twinge,” she says. “It’s not in the leg and foot, it’s at the end of the stump. But right now it’s bearable.”

Prologo believes military veterans who experience phantom pain after losing an arm or leg in combat are excellent candidates for cryoablation therapy. He is applying for a grant from the Department of Defense to fund an ambitious, multisite clinical trial at Emory, Massachusetts General Hospital, Brooke Army Medical Center, Washington University in St. Louis, and Brown University.

“Injured veterans want to return to society, get jobs, and walk with their kids,” he says, “but because of severe phantom pain, their use of orthotics and prosthetics is limited or they don’t want to wear their prosthetics at all. We think we can change that with effective cryoablation therapy.”

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