On a chilly October morning, Carl Luepker danced around a boxing ring stained with dried blood while pounding a trainer’s mitts with a flurry of combinations. A loud “thwack” echoed through the northeast Minneapolis gym with each jab.

For Luepker, 44, these sparring sessions have become a symbolic prelude to a much bigger fight — one that could transform his life and that of his 11-year-old son.

Luepker, who has a painful neurological disorder that makes it difficult for him to speak and coordinate his movements, will soon undergo a surgical procedure known as “deep brain stimulation” that, while still unproven for many disorders, is rapidly gaining acceptance in the medical world.

In January, neurosurgeons at the University of Minnesota will drill a nickel-sized hole in Luepker’s skull and implant tiny electrodes, connected to a pulse generator in his chest, to deactivate the region of his brain that is causing his disability, known as dystonia. One surgeon describes it as “like a pacemaker for the brain.’’

“The surgery is a lot like boxing,” Luepker said, as he warmed up outside the ring. “You have to get in close to your opponent and take some risks in order to come out ahead.”

Nearly 120,000 people worldwide have undergone deep brain stimulation to treat neurological disorders such as Parkinson’s disease when traditional medications failed to provide relief. While the procedure often works, U scientists are exploring ways to fine-tune the placement of electrodes in the regions of the brain that cause muscle spasms, stiffness and other often-painful symptoms of neurological disorders. In addition, Minnesota neurologists are researching a potentially groundbreaking technique that would make the procedure less invasive and give patients more control of the implants after surgery.

Currently, patients who undergo deep brain stimulation can expect to have electricity coursing into their brains at about 130 pulses per second — with no way to control it. With a $9.07 million grant from the National Institutes of Health, the U is exploring a process known as “closed-loop stimulation,” that would detect abnormal neural patterns and stimulate the brain only when needed, such as when a person attempts to walk or grab a cup of coffee. This could reduce the side effects of the surgery, which can include headaches and dizziness, researchers said.

“This [procedure] has already gone far beyond what anyone thought it could be,” said Dr. Jerrold Vitek, chair of the U’s neurology department. “But we believe that we can fine-tune this even more, so people can have a much better quality of life.”

A different persona?

Even with such advancements, many doctors and patients have been reluctant to embrace deep brain stimulation; researchers have found that only one in 10 patients who could benefit from the surgery actually undergo the procedure. Many family physicians, who handle patients with Parkinson’s disease and other neurological disorders, are unfamiliar with the technique and still rely on medication, Vitek said. Others are understandably reticent about having a hair-thin wire inserted deep inside the brain, where a slip of a millimeter can trigger a fatal bleed or life-altering stroke.

Luepker has fought what he calls “an internal battle” over whether to undergo the procedure for the past five years. In a conversation last week, the former schoolteacher said he’s less concerned about the surgical risks — doctors have assured him the chance of a brain bleed is less than 2 percent — than the possibility that he might emerge from the operating room with a new, potentially unrecognizable persona.

“I worry about my soul, that I may lose it and never get it back,” he said. “The idea of having surgeons tinkering with your brain is terrifying.”

Like many people diagnosed with dystonia at a young age, Luepker has learned to manage the symptoms through a bevy of muscle-relaxing medications. The drugs reduce the pain and frequency of his involuntary muscle contractions, but often leave him tired, groggy and less focused.

Even with a daily diet of three medications, Luepker’s speech had become so slurred and the spasms so unbearable that last year he finally had to stop teaching 6th-graders at Harambee Elementary School in Maplewood after a 20-year career. When his son recently asked him to sing a Bob Marley tune, Luepker realized his voice had become too strained to sing — a painful discovery for a musically gifted man who used to play the piano and sing in a choir.

“More and more, I began to miss who I was before dystonia took over,” he said. “I would love nothing more than to sing and play the guitar.”

But Luepker’s primary motivation is his redheaded son, Liam, who inherited the gene that causes the disorder.

Last summer, at age 10, Liam began to show the first physical signs of the condition. He now has difficulty writing and playing the violin because of his shaking hands. Each day after school and before bedtime, Liam’s father massages the tendons in his feet and calves to soothe his muscles, which cramp from prolonged muscle contractions. Luepker wants to give his son hope in a treatment that could enable him to walk and speak normally.

At first, Liam called his father a “coward” for choosing to undergo the surgery.

“He’s worried that I’m going to abandon him,” Luepker explained. But gradually, as the family discussed the procedure at home, the 6th-grader warmed to the idea of someday having the surgery if it works for his father.

“For now, I’m neutral,” Liam said matter-of-factly, as the family prepared for dinner on a recent evening. “I need to do more research.”

The surgery has the potential to be transformative.

Recently, Luepker connected with a woman from Nebraska who, like him, has struggled with dystonia since adolescence and also has a child with the condition. Twelve years ago, Kathy Johnston, 47, was confined to a wheelchair and assumed she would never walk again. Within two weeks of having deep brain stimulation surgery, she was on her feet and walking her children home from school, a 4-mile trek.

“It was nothing short of a miracle,” she said.

Johnston now oversees a drug and alcohol treatment center and recently completed a challenging hiking expedition through the jagged canyons of northwest Arizona. Her son, a student at the University of Nebraska, also underwent the procedure at age 13, and went from taking 21 pills a day to zero medications.

“I said, ‘Carl, don’t be scared, but go in with no expectations,’ ” Johnston said. “These kids of ours look to us for hope and guidance, and we need to be strong for them.”