Some 1,300 people will head to the RiverCentre in St. Paul next Saturday to learn more about the millions of patients suffering from dementia and its dominant form, Alzheimer’s disease. But the keynote address will focus on what some call “the most common disease no one has ever heard of’ ” — a brain-wasting disease that typically strikes people in their prime.

Frontotemporal dementia (FTD) strikes about as many people younger than 65 as early-onset Alzheimer’s disease, and some experts suspect it’s even more common because it’s often misdiagnosed as a psychiatric disorder or mistaken as symptoms of a midlife crisis.

Now FTD is drawing more attention because of more reliable diagnostic procedures and research that has linked it to Parkinson’s disease and to a form of dementia that results from sports injuries. The disease has even made its debut on MTV: In the series, “Teen Wolf,” the character Stiles recently discovered that he must undergo tests for FTD, which, viewers learn, killed his mother.

The attention to FTD comes as Alzheimer’s advocates and researchers are broadening their approach to dementia. “For so many years, we’ve been so limited in the focus, thinking that … dementia in general was only affecting old people,” said Debbie Richman, education and outreach director for the Minnesota-North Dakota chapter of the Alzheimer’s Association. “Yet the youngest diagnosed Alzheimer’s patient was 27; the original Alzheimer’s patient, in 1906, was 57. We have to think of this disease very differently, and all dementias very differently.”

As a result, Richman said, the group decided to focus more broadly on dementia, which is a class of disorders that degrade memory, alter personality or confound problem-solving skills. The association’s annual conference in St. Paul this year features Dr. Bruce Miller, director of the Memory and Aging Center at the University of California in San Francisco, who is among the world’s leading FTD researchers.

Journey to diagnosis can take years

While Alzheimer’s primarily affects memory, FTD attacks the judgment center of the brain, altering personality and leading to embarrassing, bizarre and sometimes risky behaviors. The “journey to diagnosis” can take years because FTD mimics other psychiatric disorders and can only be confirmed with an autopsy, said Dr. Bradley Boeve, who chairs Mayo Clinic’s behavioral neurology department. Mayo is one of the few U.S. centers for FTD research and is a collaborator in the annual dementia conference.

“It really strips people away from their persona, so they do things that are sort of out of character for them, and it’s really disturbing for the families and friends,” Boeve said. “It’s frankly very gut-wrenching. …”

Estimates of FTD’s prevalence range from 50,000 to 250,000, he said, “but that is probably a gross underestimate.” FTD has no known cure, and treatment is limited to managing symptoms, such as depression or anxiety.

Arnold Pick, a professor at the University of Prague, first identified what came to be known as FTD in 1892, when he performed autopsies on dementia patients and found tangled proteins in their brains, which came to be called “Pick bodies.” That form of the disease primarily affects behavior.

As many as half of the people with FTD have a family history that includes the disorder, Parkinson’s disease or Lou Gehrig’s disease (amyotrophic lateral sclerosis), Boeve said. In contrast, the most common form of Alzheimer’s disease, which increases in frequency above age 70, appears to be sporadic and not primarily a result of hereditary gene mutations, he said.

Boeve said the hereditary linkage in FTD could make it easier to find a way to prevent or even cure the disease if it can be caught soon enough.

Early diagnosis can be critical

Dr. Michael Rosenbloom, a behavioral neurologist at HealthPartners in the Twin Cities, worked under Miller as a fellow. He said when Miller got started, no one could even spell the disease, and now he leads one of the world’s premier research centers on the disorder.

Miller said he believes that the disorder he’s been studying for the past 30 years, once considered rare, is actually “quite common.” He said as recently as the 1990s, FTD was believed to have a single cause. Now it appears that it has different molecular causes that can be targeted for potential therapies. Because early diagnosis can be crucial, he said, primary-care physicians, psychiatric counselors and society need to be alert whenever family members complain about behavioral changes in a loved one.

“If we looked in prisons, if we looked in mental hospitals systematically, I think we might double the prevalence of this.”