LBD: Parkinson's Dark Secret

Dr. Graham Lennox, of Cambridge’s Regent’s College, called dementia “the dark secret of Parkinson’s disease.” Nancy, a surviving LBD spouse, agrees. In 2006, Nancy’s husband, Del, was diagnosed with Parkinson’s with dementia (PDD). “We were shocked,” Nancy said. “We’d been dealing with his Parkinson’s for eight years—attending the support groups, listening to all those lectures—and yet, no one, not even Del’s doctor, had mentioned dementia until that day.” Nancy’s voice caught. “We thought we were coping, but this hit us hard. We weren't prepared.”

There were several reasons for Nancy and Del’s lack of information in 2006. Years later, these reasons still exist:

a)      PDD is a “new” disorder. Dementia was not even recognized as a Parkinson’s symptom until the early 1990s. Until then, it was considered to be two diseases: Parkinson’s and dementia, likely Alzheimer’s. In 1994, “Parkinson’s disease with dementia” was included in the DSM-IV, the basic diagnostic manual for mental disorders, and added to the insurance codes. It takes at least a couple of decades for awareness of a “new” disease to develop.

b)      PD doctors are movement, not dementia, specialists. Neurologists who specialize in treating Parkinson’s focus heavily on movement issues and are less likely to be trained to recognize early signs of PDD. Thus their patients’ dementia may go untreated until it is so severe that it can’t be ignored.

c)      Cross-sectional studies don’t tell the true story. Although dementia has finally become recognized as a symptom of PD, Parkinson’s websites often quote cross-sectional studies, which are a  single “snapshot” of a specified group of people—in this case, people with PD. These usually report a 10% to 30% rate of occurrence, numbers that make the possibility of impending dementia easy to ignore—or deny. Cumulative studies, which are of a group of people over time, show a different picture, with from 65% to 80% of Parkinson’s patients eventually developing dementia.

d)     Parkinson’s disease with dementia is often considered a symptom of late stage PD.  Although the possibility of PDD does increase with age, dementia can occur at any time, sometimes within months of a Parkinson’s diagnosis. Additionally, recent studies have found that mild cognitive impairment (MCI-LB), a major risk for eventual PDD, is often present in PD’s early stages—even at diagnosis.

 “Please spread the word,” Nancy begs. “Don’t leave other families in the dark as we were.” That’s our goal with this blog, our trainings, our book and our bookstore. You can help by telling others about these and about Parkinson’s and its connection to Lewy body dementia.