We’ve helped over 1,500 families donate a loved one’s brain, so we have read many neuropathology reports. About half the time, people diagnosed clinically with multiple system atrophy (MSA) end up with a brain donation report that says the person had “Lewy body disease.” And, some of the time, people diagnosed clinically with Lewy body dementia (LBD) end up with a brain donation report that says the person had “Lewy body disease.” Same thing for people diagnosed clinically with Dementia with Lewy bodies. And, a lot of the time, people diagnosed clinically with Parkinson’s disease (PD) end up with a brain donation report that says the person had “Lewy body disease.”
Oh, the terminology is confusing! I wish neuropathologists would use language that we laypeople can understand.
The most common Lewy body disease is Parkinson’s disease
The second most common Lewy body disease is Lewy body dementia, also called PD dementia
Parkinson’s disease is a clinical diagnosis, not a neuropathologic one. We have to read deeper into a report to know if, when a report indicates the person had “Lewy body disease”, if it means that they had Parkinson’s disease or something else. Reports usually refer to the “likelihood” someone has Lewy body dementia. If the likelihood is “low,” then we’d call this PD. If the likelihood is “intermediate” or “high,” we must know the person’s symptoms. If the person did not have hallucinations, delusions, or progressive dementia, we’d call this PD. If a person had mild cognitive impairment and no hallucinations, we’d call this PD.
Similarly, Lewy body dementia is a clinical diagnosis, not a neuropathologic one. And, as with PD, we have to read deeper into a report. Reports usually refer to the “likelihood” someone has Lewy body dementia. If the likelihood is “intermediate” or “high,” we must know the person’s symptoms. If the person had hallucinations or delusions, and progressive dementia, we’d call this LBD.
Finally, Dementia with Lewy bodies (DLB) is a research diagnosis, not a neuropathologic one. Not many people are given this diagnosis. It’s given to people who have dementia or psychosis (hallucinations or delusions) at least one year before parkinsonism symptoms. As with LBD, reports usually refer to the “likelihood” someone has Lewy body dementia. If the likelihood is “intermediate” or “high,” we must know the person’s symptoms. If the person had hallucinations or delusions, and progressive dementia, we’d call this LBD or DLB. Often, reports note the so-called “one-year rule” in identifying whether the person would be considered as having DLB. (DLB is included under the Lewy body dementia umbrella.)
Still confused?
Please contact the brain donation case manager who assisted you or contact us. Or the brain bank. Or consult with the diagnosing neurologist. Neurologists don’t read many of these reports, though, and often find the language confusing. However, neurologists do know that “Lewy body disease” can refer to PD.
One last point. In our many years of coordinating local caregiver support groups, many people refer to “Lewy bodies” as akin to something that causes hallucinations. Lewy bodies are aggregations of alpha-synuclein proteins. Lewy bodies are found in PD, Lewy body dementia, and DLB. Lewy bodies are not found in MSA.
Robin
Founder and CEO
Brain Support Network