Joined: Fri Aug 11, 2006 1:46 pm
Location: SF Bay Area (Northern CA)
PDD: comparing patients with and w/o Alzheimer's disease
There are 3 or 4 interesting articles on LBD in 2009, and this is among them.
In this Sun Health Research Institute study, the clinical records of 23 people with PDD (Parkinson's Disease Dementia) without AD (Alzheimer's Disease) were compared to records of 28 people with PDD and AD.
They found that: "PDD+AD subjects were significantly older at age of PD onset and death, progressed to onset of dementia in less time, and had a shorter duration of PD symptoms before the onset of dementia."
On a host of other factors -- presence of cognitive fluctuations and hallucinations, mean MMSE, etc -- there was no difference between the two groups. This means that the two groups cannot be distinguished in a clinical setting. (So, the only way to know if there's AD present is to conduct a brain autopsy.)
"PDD-AD and PDD+AD have similar degrees of dementia and approximately half of PDD subjects have enough AD pathology to attain a neuropathologic diagnosis of AD. PDD can develop in the absence of significant Alzheimer pathology."
I've copied the abstract below.
Alzheimer's Disease & Associated Disorders. 2009 Jul-Sep;23(3):295-7.
Parkinson disease with dementia: comparing patients with and without Alzheimer pathology.
Sabbagh MN, Adler CH, Lahti TJ, Connor DJ, Vedders L, Peterson LK, Caviness JN, Shill HA, Sue LI, Ziabreva I, Perry E, Ballard CG, Aarsland D, Walker DG, Beach TG.
The Cleo Roberts Center for Clinical Research, Harold Civin Laboratory of Neuropathology, Sun Health Research Institute, Sun City, AZ.
Subjects with Parkinson disease (PD) frequently develop dementia with greater than one-third meeting neuropathologic diagnostic criteria for Alzheimer disease (AD).
The objective is to identify clinical and neuropathologic differences between Parkinson disease with dementia (PDD) subjects, with and without coexistent AD pathology. Neuropathologic examination was available on subjects diagnosed by clinicopathologic criteria with PDD-AD (N=23) and PDD+AD (N=28).
A small subset of subjects with PDD-AD and PDD+AD had received at least 1 standardized neuropsychologic assessment.
PDD+AD subjects were significantly older at age of PD onset and death, progressed to onset of dementia in less time, and had a shorter duration of PD symptoms before the onset of dementia.
Education, responsiveness of L-dopa and dopaminergic medications, presence of cognitive fluctuations and hallucinations, and mean Mini-Mental State Examination, Global Deterioration Scale, Functional Assessment Staging, and Unified Parkinson Disease Rating Scale scores did not differ significantly between the 2 groups.
The PDD+AD group had significantly greater total plaques, neuritic plaques, total tangles, and Braak stages compared with PDD-AD.
This study suggests that it is difficult to distinguish PDD+AD and PDD-AD on the basis of movement, clinical, and neuropsychologic assessment.
PDD-AD and PDD+AD have similar degrees of dementia and approximately half of PDD subjects have enough AD pathology to attain a neuropathologic diagnosis of AD. PDD can develop in the absence of significant Alzheimer pathology.
PubMed ID#: 19812474 (see pubmed.gov for the abstract only)