Tom Schneider experienced a slow but steady decline since his 2011 Parkinson’s disease diagnosis.

His voice softened. His joints became stiffer, his face less expressive. By 2018, Tom now 60, took two or three tablets of the medication Sinemet up to seven times a day.

That is, until October, when Spectrum Health neurosurgeon Hayden Boyce, MD, and neurologist R. Ross Coleman, MD, implanted a pair of devices in Schneider’s brain in a procedure called deep brain stimulation. From the moment Dr. Coleman activated the device, life has been different for Tom and his wife, Julie.

“It was like turning back the clock,” Julie recalled. “Immediately, I thought, ‘I know that guy.’ I didn’t realize how much I had missed him.”

Tom’s voice became louder and stronger, his speech improved, his movements became more fluid “and I feel like he has the ability to communicate again,” Julie said. “We have young grandkids and if Tom isn’t expressive enough, it is difficult for them.”

A couple months after Dr. Coleman activated the electrodes implanted in Tom’s brain, the Schoolcraft, Michigan, man returned to Spectrum Health for a checkup.

In addition to improved speech and a decrease in tremors, his handwriting is more legible and he’s eating and sleeping better, Tom told Dr. Coleman. He’s playing the piano again and doing a little woodworking.

“My hands are better but my right foot is still an issue,” he said. The tremors in his foot are most obvious when he hits the dampening pedal on his piano. He studied piano performance in college and stopped playing in recent years as his Parkinson’s symptoms progressed.

So doctor and patient sat down at a piano outside Dr. Coleman’s office for a short concert. Tom pulled sheet music from his wife’s bag, removed his wire-rimmed glasses and launched into a piece composed by Johann Sebastian Bach.

Using a controller the size of a tablet, Dr. Coleman initiated micro-adjustments to the high-frequency signals emanating from the leads deep inside Schneider’s head—one on the right side of his brain and another on the left. The signals stimulate areas of the brain that control movement, compensating for the damage done by Parkinson’s.

“It’s kind of like a pacemaker for the brain,” Dr. Coleman explained.

Each lead resembles a spaghetti noodle and is about 16 inches long. The end implanted in the brain has four contacts. Which of the contacts receive voltage and how much varies for each patient. So does the precise location of the noodle-like device. The opposite end of the lead snakes down the neck and into a battery pack implanted under the skin.

No portion of the device is visible as Dr. Coleman adjusts the voltage. But it’s clear that different settings temper or exacerbate the tremor in Tom’s foot and his ability to steady his hands and speak clearly. Tom, meanwhile, can only detect a change in his tremor. He can’t feel the electrical impulses.

“The programming is tailored to each patient. We identify goals before we plan for surgery and we still focus on those goals afterward,” Dr. Coleman said. “One of Tom’s goals was more quality time with family and friends. And golf and piano.”

Deep brain stimulation gives Tom more “on time,” Dr. Coleman said, which is when medication is working and he is functioning at his best. When he took medication seven times a day, he inevitably experienced lots of “off time” as dosages wore off.

“As the disease progresses, medication doesn’t last as long,” Dr. Coleman said.

Only 10 to 20 percent of those who have Parkinson’s are good candidates for deep brain stimulation surgery, Dr. Coleman said. First, doctors must be confident the patient truly has Parkinson’s, which takes about four years of monitoring symptoms and progression of the disease. Then doctors evaluate whether tremors are responding to medication. If not, or if medications are actually causing more involuntary movement or negative side effects, deep brain stimulation may be a good option.

Thomas’ suspicion that “something wasn’t right” with his health dates back more than two decades. He lost his sense of smell, an early and often overlooked symptom, in 2003 and began experiencing tremors in 2010. A diagnosis of Parkinson’s disease was confirmed a year later.

“You don’t recover. It’s progressive,” he said.

Indeed, deep brain stimulation is not a cure, Dr. Coleman said. It’s good at improving motor skills but won’t help with balance, memory loss, depression or dizziness. He was surprised Tom’s voice improved as a result of the procedure because deep brain stimulation does not typically affect the patient’s voice.

Drs. Boyce and Coleman implanted the leads in two separate surgeries. Dr. Boyce created a nickel-sized hole in Tom’s skull, first on his left side then, one week later, on his right. After the opening was created, they woke Tom. Dr. Boyce threaded the wire into the subthalamic nucleus while Dr. Coleman mapped the route and then turned on the current. Then the pair fine-tuned the placement based on the pattern of brain cell electrical activity and how Tom’s symptoms responded.

“A 2 millimeter change in placement can make a pretty big difference,” Dr. Coleman said.

Five days after his procedure, Tom returned to the hospital for installation of the battery pack.

“The main difference is my interaction with Julie,” Tom said. The couple met in English class at Northern Michigan University and has been married for 38 years. Tom earned a degree in computer sciences and worked as a clinical program manager or director until he retired last year.

“He feels like he has more hours in the day,” Julie said. “We are hoping this will last for a really long time.”

Dr. Boyce, who has been performing this surgery for more than 10 years, says deep brain stimulation has also improved the quality of life for some patients with epilepsy, essential tremor or dystonia.

In recent years, it has become more patient friendly, including the option of implanting the devices under general anesthesia using an MRI. That surgery has become popular for those who can’t overcome the fear of being awake during brain surgery.

“It’s really rewarding to see the real-life implications, to see how what you are doing is immediately improving somebody’s quality of life,” Dr. Coleman said. “That’s pretty awesome.”