Google the terms “Lewy body dementia” and “Alzheimer’s disease” appears in most search results. The two are linked through common symptoms, but their differences can have drastic implications. In this month’s Cerebrum story: “Lewy Body Dementia: The Under-Recognized But Common Foe,” by James E. Galvin, M.D., M.P.H., and Meera Balasubramaniam, M.D., the authors stress that diagnosing Lewy body dementia (LBD) incorrectly, or as Alzheimer’s disease, “may expose patients to potentially dangerous adverse reactions to certain medications (such as classic neuroleptic medications like haloperidol).” The writers add: “Early and accurate diagnosis helps families prepare for their role in caregiving, specifically the behavioral management and their own emotional preparation in anticipation of the disease course, one that may have its own unique challenges and burdens.”
After Alzheimer’s disease, LBD is the most prevalent progressive dementia of the more than 100 forms. LBD, which affects 1.3 million people in the US, is characterized by the presence of Lewy bodies, which are abnormal aggregates of a protein called alpha-synuclein. Found in regions of the brain that regulate behavior, memory, movement, and personality, Lewy bodies were first described in the early 1900s by Friederich H. Lewy while researching Parkinson’s disease. The first case of LBD, however, was not described until 1961, with the first set of clinical criteria introduced in 1996.
Because many of the symptoms of Alzheimer’s, Parkinson’s, and LBD overlap, LBD is difficult to diagnose. Underdiagnosis is just part of the reason why LBD is not well known to the public or many health-care providers, and why funding for research to find the causes and develop therapies for LBD lags far behind that for almost every other cognitive disorder.
The authors, who collaborate at the New York University Langone School of Medicine, point out ways to recognize the differences between LBD and Alzheimer’s. “In its early stages, LBD is more likely to be associated with psychiatric symptoms. The patient not only sees nonexistent people, animals, body parts, or even vehicles, but may describe them in detail. He or she may even respond by talking to the hallucinations. Paranoia toward caregivers and unshakable false beliefs, such as that family members are being replaced by impostors, are more prevalent among individuals with LBD than among Alzheimer’s patients.” But they also warn that “patients with Alzheimer’s frequently develop psychotic symptoms later in the course of the disease, such that the late stages of LBD and Alzheimer’s may be indistinguishable.”
The authors advocate drug development, but acknowledge that the problems diagnosing LBD means finding appropriate patients for therapy is a factor in holding clinical trials. The good news is that drugs that become FDA-approved for dementia in Parkinson’s and in Alzheimer’s may be ideal candidates for future clinical trials in LBD.
The ramifications for underfunding are serious. The most rigorous study to date about the financial costs to care for people with dementia, published last April in the New England Journal of Medicine, found that the financial burden is at least that of heart disease or cancer, and probably higher. The New York Times concluded that “the bottom line is that both the costs and the number of people with dementia will more than double within 30 years, skyrocketing at a rate that rarely occurs with a chronic disease.”
Families who have a loved one with LBD dementia would most likely point out that the emotional burden can’t be measured in dollars.