Parkinson disease with dementia: comparing patients with and without Alzheimer pathology.

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.

Studies on the effect of the apolipoprotein E genotype on the lipid profile in Alzheimer's disease.

OBJECTIVE: To determine whether Apolipoprotein E4 (Apo E4) gene status or ApoE gene dose affect the lipid profile in AD. BACKGROUND: Links between hypercholesterolemia and AD development continue to grow. Presently, limited information exists about the influence of the Apo E genotype on the lipid profile characteristics in AD. METHODS: We examined the lipid profiles (total cholesterol (TC), high-density lipoprotein (HDL), lower-density lipoprotein (LDL), TC/HDL ratio, and triglyceride (TG) levels) of 142 subjects with probable or possible AD (mean age 76.5 +/- 8.9 years), not on lipid lowering therapy by Apo E genotype. Assessment was done by gene status and gene dose. RESULTS: ApoE4 gene status did not reveal any significant differences in the lipid profile except for LDL. However, significant differences were observed by ApoE gene dose. CONCLUSION: ApoE gene status has minimal influence on the lipid panel or mean age in AD. Apo E gene dose does influence the lipid panel with Apo E 2/2, and 2/3 having significantly better lipid panels and older age of onset.