Roy and Lynn Roden bicycled up the snowy mountains in Washington and through a sandstorm in the New Mexican desert. They picked apples, marveled at seals and hummingbirds — and grew closer with each mile.

Most of all, they spread the word about Parkinson’s disease, as they rode cross-country from Seattle back to Miami with their two dogs riding behind them in carriers. Samantha is their Labradoodle; Oliver, their English springer spaniel.

“If I can travel 5,000 miles on a bicycle, maybe it can motivate someone to get out of the house, and just take a bike ride or walk around the block and get some exercise,” said Roy Roden, 55, of North Miami Beach, who has Parkinson’s.

Roden and his wife returned to Miami on Friday, completing their four-month “PD Challenge.” Looking trim, fit and tanned, they cycled to the University of Miami Miller School of Medicine amid much fanfare, welcomed by Roy’s doctors, family, friends and other members of the Parkinson’s disease community.

“It’s an amazing trip, and it’s obviously going to increase awareness of Parkinson’s disease and that there are treatment options that improve quality of life,” said Dr. Jonathan Jagid, a neurosurgeon and associate professor at UM Miller School of Medicine.

During their adventure, the Rodens met with Parkinson’s patients and researchers, sharing their experiences of managing the disease. Roy encouraged patients to join clinical trials and spoke about the benefits of Deep Brain Stimulation, a treatment he underwent in July that suppresses Parkinson’s symptoms.

“Talking to people about their disease and to other care partners about how it affects them, that was one of the best things for me,” said Lynn, Roy’s wife.

A progressive, neurodegenerative brain disorder, Parkinson’s is the second most common degenerative disease of the brain after Alzheimer’s. It affects one million people in the United States, including an estimated 35,000 in South Florida, according to the National Parkinson Foundation, which is based in Miami.

Each year, about 50,000 to 60,000 cases of Parkinson’s are diagnosed, with an average age at diagnosis of 62. With the aging of the baby boomer population, diagnoses are expected to double by 2030.

Among its symptoms, Parkinson’s causes tremors, slowness of movement and rigidity. Those with the disease can also display a host of other early signs, including loss of smell. The disorder can also affect cognition and gastrointestinal functions.

The disease is caused in large part by a deficiency in the brain of the neurochemical dopamine, and progression can take at least a decade. About 15 percent of cases are known to be familial, and the other 85 percent are due to unknown genetic and environmental factors, said Dr. Carlos Singer, professor of neurology at UM and division chief of Parkinson’s and movement disorders.

Roy experienced his first symptom, insomnia, at age 25. Over the next 25 years, he displayed other symptoms: difficulty holding a spoon, hand tremors, memory problems and an unexplained twitch. In 2009, after visiting many doctors, he was finally diagnosed with Parkinson’s.

Last July, Jagid, the UM neurosurgeon, and Dr. Bruno V. Gallo, assistant professor of neurology and neurosurgery and director of the Deep Brain Stimulation program at UM, surgically implanted a device into Roden’s chest with wires leading to his brain. The device, similar to a pacemaker, delivers electrical impulses to precisely targeted areas of the brain involving motor control and muscle function.