Recently I purchased a book by Eric Ahlskog, MD, PhD, a well-regarded movement disorder specialist at Mayo Rochester. The book title is “Dementia with Lewy Bodies & Parkinson’s Disease Dementia: Patient, Family, and Clinician Working Together for Better Outcomes.”
I’ll put it in our support group lending library for someone to borrow at the next support group meeting. By the way, if you are interested in making an in-kind donation of books to the support group, a non-profit organization, let me know. Our wish list is long!
I read three chapters today — one on background, one on symptoms/diagnosis, and one on treatment — and skimmed through the rest. Based on three chapters, I’d say this is a wonderful book. It contains the precision of a researcher and clinician, but worded in such a way that we laypeople can understand. I’ve copied a few excerpts below.
There isn’t anything new in the book for me, but I’ve been reading about Lewy body diseases for quite awhile. There may be new things for you!
Dementia with Lewy Bodies & Parkinson’s Disease Dementia: Patient, Family, and Clinician Working Together for Better Outcomes
by Eric Ahlskog, MD, PhD
“The dementia of both DLB and PDD is due to the Lewy body neurodegenerative process. However, three other factors also contribute, to varying degrees. By themselves, these other three factors are not the primary causes of dementia in Lewy conditions but are additive… One such factor is cerebrovascular disease, which may be…unrecognized; it may also manifest as brain atherosclerosis (hardening of the arteries). Atherosclerosis of small brain arteries is the reason for leukoaraiosis, which is the white blush present to varying extents on the [MRI] brain scans of older adults. Treating risk factors for such cerebrovascular disease, especially earlier in life, is wise; however, once dementia is present it may be too late. Such risk factors include hypertension, diabetes mellitus, elevated cholesterol., smoking, and lack of exercise.”
“A second contributor to dementia, but not a major factor in DLB or PDD, is Alzheimer brain pathology… Such microscopic changes slowly accumulate with aging in most humans, even those without dementia. In many older adults they are modest and not sufficient to result in dementia. However, in a brain already challenged with Lewy neurodegenerative pathology, there is little reserve; a small degree of brain Alzheimer pathology will be additive. Such changes are noted in many, but not all, with DLB or PDD.”
“Finally, contributing to the dementia of DLB and PDD is normal brain aging. With passing decades of life our brains shrink, which is very apparent on MRI brain scans in those over age 80 years. This is primarily due to loss of brain connections as part of the aging process. Although there is a modest, age-related loss of brain cells (neurons), the primary reason for brain shrinkage is loss of synapses and the connecting neuron circuitry (axon terminals, portion of dendrites). Fortunately, many older adults without Alzheimer’s or Lewy disease are able to compensate for this age-related brain shrinkage, but it is additive if neurodegenerative disorders are present.”
Why and How Do We Distinguish DLB from PDD?
“PDD starts as Parkinson’s disease, which then progresses to include dementia; those with DLB start out with dementia. Are these just different ends of a single spectrum? Are they really the same disorder? This is an unresolved question.”
“Parkinson’s disease is devoid of intellectual problems when it first develops. In contrast, cognitive impairment is present at the onset of DLB, sometimes with parkinsonism delayed. In fact, some people with DLB never experience parkinsonism.”
“How do researchers make the distinction? … An international consensus panel has institute the so-called 1-year rule to separate DLB from PDD. … Obviously, this is a little arbitrary, but such distinctions help researchers clearly define what they are studying. In the clinic, where clinicians deal with real people and their problems, that distinction is less crucial.”
Fluctuations in Thinking and Alertness
“Unique to these Lewy dementias is the fluctuation of mental clarity. People with DLB or PDD may be alert and lucid during portions of the day, but inexplicably confused several hours later. This is a hallmark of DLB and PDD. Daytime drowsiness may similarly fluctuate like this, although there may be other treatable reasons for sleepiness… The reason for these fluctuations in mental clarity is unknown.”