PDD Groups Research Articles

Characterizing mild cognitive impairment in Parkinson's disease

There is growing interest in identifying Parkinson's disease (PD) patients with mild cognitive impairment (PD-MCI), but widely disparate criteria have been used. We assessed 143 PD patients and 50 matched controls on 20 measures across 4 cognitive domains (executive function, attention and working memory, learning and memory, visuoperception). Twenty-four patients met criteria for dementia (PD-D); nondementia patients were classified as either with normal cognition or MCI for 12 neuropsychological criteria. We compared the influence of these criteria on the distribution of global cognitive performance in the resulting PD-MCI groups relative to the control and PD-D groups. Different criteria produced substantial variation in the proportion of PD-MCI cases identified. Fourteen percent PD-MCI was found when using 2 scores in 1 domain at 2 standard deviations (SD) below normative scores, with no controls identified as MCI, through to 89% PD-MCI with 1 score in 1 domain at 1 SD below normative scores, when 70% of controls were identified as MCI. The balance of cases with impaired cognition but not those with generally intact cognition was better served by using criteria that required 2 specific deficit scores or deficits across 2 domains. As comparisons with external normative data may have greater applicability across centers, we suggest that 2 scores at -1.5 SD within any single domain (30% PD-MCI) or 1 score at -1.5 SD in each of 2 domains (37% PD-MCI) provide suitable criteria to minimize the inclusion of cognitively well patients. Clinical dementia rating did not improve the relative identification of cognitively impaired and unimpaired nondementia PD patients.

P2-270: Behavioral and psychological symptoms of dementia, of cognitive impairment no dementia and mild Alzheimer's disease in community-dwelling elderly

disinhibition was relatively more common in the SVD patients. These results suggest that neuropsychiatric symptoms are more prominent in PDD and SVD patients than in AD patients with early stage of dementia, because PDD and SVD groups are more related deficits in the frontalsubcortical circuits. Acknowledgment: This study was supported by a grant of the Korea Health 21 R&D Project, Ministry of Health & Welfare, Republic of Korea (A050079).

Motor subtype and cognitive decline in Parkinson’s disease, Parkinson’s disease with dementia, and dementia with Lewy bodies

Background: A previous cross sectional study found over-representation of a postural instability gait difficulty (PIGD) motor subtype in Parkinson’s disease patients with dementia (PDD) and dementia with Lewy bodies (DLB),...

Longitudinal study of cerebral blood flow SPECT in Parkinson's disease with dementia, and dementia with Lewy bodies

People with Parkinson's disease (PD) have an increased risk of developing dementia (PDD), which often has clinical features similar to dementia with Lewy bodies (DLB). Whilst perfusion studies have shown parieto-occipital hypoperfusion in DLB and PDD relative to controls, there have not been any longitudinal studies of perfusion changes in PDD and DLB. In this study, we measured brain perfusion using Tc99m HMPAO SPECT over one year in 17 PDD, 18 DLB and 34 healthy subjects. We used SPM99 to compare perfusion changes in the two dementia groups against the control group. We did not see any reductions in perfusion in either of the dementia groups. However, in the DLB, but not PDD group, there was a significant increase in putamen perfusion relative to controls over the year. In both DLB and PDD groups, there was a correlation between striatal perfusion increase over the year, and worsening of parkinsonism. Perfusion changes were not secondary to changes in antiparkinsonian medication. The increase in striatal perfusion may be a compensatory change related to decreasing striatal dopaminergic input from the substantia nigra in PDD and DLB, consistent with the increased predominance of rigidity over tremor symptoms in these groups compared with non-demented PD.

Pentagon drawing and neuropsychological performance in Dementia with Lewy Bodies, Alzheimer's disease, Parkinson's disease and Parkinson's disease with dementia.

Early and accurate diagnosis of Dementia with Lewy Bodies (DLB) to allow the appropriate clinical treatment is a priority, given reports of severe neuroleptic sensitivity and a preferential response to cholinesterase inhibitors in these patients. There have been suggestions that constructional apraxia is prevalent in DLB, and may provide a sensitive marker of the disease. This study examined the pentagon drawings of 100 DLB patients, 50 Alzheimer's disease (AD) patients, 81 Parkinson's disease (PD) patients of whom 36 suffered from dementia (PDD). Performance on this task was correlated with cognitive performance on the MMSE and CAMCOG scales. Patients with DLB were found to draw significantly worse pentagons than those with AD or PD, but not those with PDD. Drawing scores were significantly correlated with MMSE scores for the AD and PDD groups but not those with DLB. More detailed analysis of the neuropsychological correlates of constructional performance for patients with AD and DLB, revealed that those with AD showed a broad cognitive basis to their impairment, in DLB drawing was linked only to perception and praxis. This study has suggests that DLB subjects show an impairment of pentagon copying that is dissociable from more global cognitive impairments, whereas PD patients are relatively unimpaired on pentagon copying and AD and PDD patients show a linkage of their impairment in copying with more global cognitive deficits.