[18F]FDG-PET study in dementia with lewy bodies and alzheimer's disease

Due to similar presenting symptoms, many physicians find it difficult to distinguish cases of dementia with Lewy bodies (DLB) from Alzheimer’s disease or Parkinson’s disease with dementia. The pathologic diagnosis of DLB has improved because of the discovery of probes for α-synuclein, a protein found in Lewy bodies. However, pathologic diagnosis can be employed postmortem only, and therefore diagnostic techniques that can be employed to guide patient management are still needed. Consensus criteria have been developed for establishing a clinical diagnosis of DLB, but they lack sensitivity. Therefore, a review of the recent literature was conducted to establish whether neuroimaging studies are useful diagnostic tools to help differentiate these syndromes. At least six types of tests can be used to image the brain of patients with dementia. Structural studies (x-ray, magnetic resonance imaging and computerized tomography) can disclose the presence of stroke sequelae and other lesions, whereas functional studies (magnetic resonance spectroscopy, positron emission tomography and single-photon emission computed tomography) can disclose metabolic and blood flow alterations that may be characteristic for different types of dementia. Although more formal studies are needed to confirm that these imaging techniques are reliable diagnostic tools for DLB and permit the establishment of guidelines for their use, neuroimaging techniques currently are being employed in practice to differentiate dementia types as a guide to treatment.

Section: Functional Studies For Differentiating Dlb From Adsupporting

confidence: 75%

Neuroimaging as a Diagnostic Tool in Dementia with Lewy Bodies

Small¹

2003

“…According to the hypothesis described in detail by Scarmeas et al [7] , we expected an inverse association between schooling and glucose metabolism as a measure of neuronal function in brain areas primarily affected by the disorder, controlling for cognitive symptom severity. We therefore hypothesized that metabolic correlates of BRC in DLB should be found in posterior temporal and parietal association cortices and in the occipital association cortex [8] .…”

Section: Introductionmentioning

confidence: 99%

Metabolic Correlates of Brain Reserve in Dementia with Lewy Bodies: An FDG PET Study

Perneczky¹,

Häussermann

Diehl‐Schmid³

et al. 2007

Background: Studies suggest that brain reserve allows patients with more years of schooling to cope better with brain damage. Research has been mainly focussed on Alzheimer’s disease and no studies exist on patients with dementia with Lewy bodies (DLB). The aim of this study was to provide evidence for brain reserve in DLB. Methods: Twenty-one consecutive patients with DLB and 16 age-matched healthy controls were included. The participants underwent cerebral ¹⁸F-FDG PET imaging at rest. A group comparison was conducted in SPM2 between the patient and control groups. A linear regression analysis with glucose metabolism as the dependent and years of schooling as the independent variable was performed. Age, gender and a total score of the Consortium to Establish a Registry for Alzheimer’s Disease neuropsychological battery were included as covariates into the analysis. Results: The patients showed a significant metabolic reduction in the frontal and posterior association cortices, the basal ganglia and the pulvinar of the thalami. Glucose metabolism and education showed an inverse relationship in an extensive cluster in the left temporo-parieto-occipital cortex. Conclusion: Similar findings were previously reported in Alzheimer’s disease and are regarded as evidence for brain reserve. Therefore, we suggest that brain reserve is also present in DLB.

“…This is consistent with the sensitivity of these criteria of 78%, which has been found in clinicopathological correlations [8] . Diagnostic sensitivity may possibly be improved by including more sensitive tests of attention and executive ability in the neuropsychological evaluation and by using the full range of diagnostic possibilities, such as positron emission tomography [39,42,43] , brain perfusion scintigraphy [44] and liquor markers [45][46][47] .…”

Section: Discussionmentioning

confidence: 99%

The Alzheimer Variant of Lewy Body Disease: A Pathologically Confirmed Case-Control Study

Perneczky

Mösch²,

Neumann³

et al. 2005

The objective of the study was to identify clinical features that distinguish patients with dementia with Lewy bodies (DLB), who were classified as Alzheimer’s disease (AD) patients, from patients with AD. We examined a group of 27 patients from our memory clinic, originally diagnosed with AD, of whom 6 were postmortem found to have DLB. For the present study, we compared cognitive, noncognitive and neurological symptoms between the two groups. We found that there were no differences on ratings of dementia and scales for activities of daily living. Patients with DLB performed better on the MMSE and the memory subtest of the CAMCOG, but there was no difference in any other cognitive domain. Furthermore, genetic risk factors, including family history of dementia or allele frequency of the apolipoprotein ε4, did not discriminate between the two groups, and there were no differences on CCT scans. Taken together, our findings suggest that Lewy body pathology may be present in patients who do not show the typical clinical features which distinguish DLB from AD.