TRAVERSE CITY — Larry Kustra was diagnosed with multiple sclerosis about 10 years ago and now leads a support group.

The Traverse City resident also has a team signed up for what will be his seventh year participating in the MS Walk taking place June 22 at Traverse City Central High School.

A recent study shows that the number of people living with MS is on the rise, which makes the money raised at the event so important, he said.

The money funds research and services for those with the disease, plus, the walk is just plain fun, Kustra said.

"It's quite a sight," he said. "You see all these people in orange t-shirts and costumes. You see people on scooters and walking with canes ... People are just happy to be out there and joining in the comradery with other patients and supporters."

A recent MS Prevalence Study funded by the National Multiple Sclerosis Society (NMSS) shows that in 2010 the estimated 10-year prevalence of adults in the U.S. was 727,344 cases, not the 400,000 that had previously been thought.

In addition, the study shows the prevalence of MS cases from 2000 to 2017 is now estimated at 913,925 cases, though that number may be as high 1,000,000.

The study looked at nearly half of the U.S. population using datasets of health claims from both private and government-sponsored insurance programs, such as Medicare, Medicaid and the Veterans Administration.

Dr. Robert P. Lisak, who specializes in neuroimmunologic diseases at Wayne State University School of Medicine, said that an initial increase in the numbers of people with MS was thought to be because of better diagnostic tools and more awareness of the disease.

"But over the last 10 to 20 years we think there are more cases," Lisak said, though nobody knows why.

"The problem is if you don't know the cause of the disease you can speculate all you want, but you don't really know," he said.

The MS Walk has been going on across the U.S. for 32 years and just surpassed the $1 billion fundraising mark. The walk has been hosted in Traverse City for more than 20 years, said Tammy Willis, executive director of NMSS.

There are usually about 200 people who participate locally, Willis said. So far this year more than 250 people have signed up and the goal is to raise $60,000, about $3,000 more than last year, she said.

"It's such a prevalent disease," Willis said. "Events like this walk are the way we raise funds to support people who are living with MS."

MS occurs when a person's immune system attacks the fatty myelin that protects nerve fibers. Nerves become damaged and the transmission of signals between the brain, spinal cord and the rest of the body is disrupted.

Symptoms are different for everyone, but commonly include fatigue, numbness or tingling, muscle weakness, vision problems and difficulty walking.

Research over the last 20 years has shown that an interaction between genetics and some environmental factors increase a person's risk of contracting the disease, according to information at the National Multiple Sclerosis Society.

Childhood obesity, smoking, a deficiency of Vitamin D and exposure to the Epstein-Barr virus likely all play a role in the disease.

Women under 45 with MS outnumber men by about a 3:1 ratio, something Lisak said may be attributed to the influence of hormones.

"But there is probably no one single cause or one single risk factor," Lisak said.

Lisak said there are new medications out that delay or even prevent progression of the disease. But researchers still need to find out what ultimately causes MS — the mechanisms of what causes attacks, what causes attacks to shut off and what causes progression.

Until that is known it is hard to develop therapies, he said.

"We need to get more basic knowledge in order to make further progress."

If you walk:

What: MS Walk to raise funds for research and services for those affected

When: 10 a.m. June 22

Where: Traverse City Central High School, 1150 Milliken Dr.

Register: Visit walkMS.org, call 855-372-1331 or email fundraisingsupport@nmss.org.

An MS support group meets at 6:30 p.m. on the third Wednesday of every month at the Foster Family Community Health Center, formerly the Munson Community Health Center. Those with MS and their caregivers, friends and family are all welcome.

Walk MS Video: https://www.youtube.com/watch?v=xNJubobKrtY