The paper reviewed here is ‘Magnetic Resonance Imaging in Lewy Body Dementia’ by John O’Brien and colleagues and freely available here. The paper was published online in December 2009.
This is a review article which examines the distinction between Parkinson’s Disease and Lewy Body Dementia using Magnetic Resonance Imaging (MRI). The authors identify the low sensitivity of diagnostic criteria for identification of LBD and the need to incorporate biomarkers from additional investigations such as MRI.
Method: The authors undertook a review of the literature using Medline. The search took place between the years 1966 and 2009 using the search terms
- ‘Lewy and Mag * Res *’
- ‘Parkinson, dementia and Mag’
Studies with at least 5 subjects were included and the references from retrieved papers were searched for additional information.
Results: The authors retrieved 50 papers through the search method above. The retrieved studies utilised several imaging technologies
- Structural MRI
- Functional MRI
- MRI Diffuse Tensor Imaging
- Proton Magnetic Spectroscopy
The results are concisely summarised in Table 1 in the paper.
1. Structural MRI
The authors identify three methodological approaches used within the retrived structural MRI studies
- Region of Interest Analysis
- Visual Inspection
- Voxel Based Morphometry
The data from the studies are not pooled as far as I could see and commentary is made on individual studies. With regard to cortical atrophy the authors identify heterogeneity in the findings in Parkinson’s Disease Dementia (PDD) and LBD. Similarly for rates of cortical atrophy findings were heterogenous although there was a trend to finding a more rapid rate of degeneration in Alzheimer’s Disease (AD). The authors cite evidence suggesting that the Medial Temporal Lobe, subfields within the hippocampus and particularly the Substantia Nigra could be useful in discriminating PDD + LBD from AD. The hippocampus findings looked quite interesting.
2. MR Diffuse Tensor Imaging
The authors discuss findings in the corpus callosum, posterior cingulate and precuneus in LBD.
3. Proton Magnetic Spectroscopy
Positive findings in PDD are discussed which have similarity to those found in AD. The reported findings in LBD were relatively unremarkable.
The authors discuss an exploratory study in which there was reduced occipital cortex activity during a visual task in subjects with LBD compared to those with AD.
This is a recent paper in which the authors have retrieved 50 papers relevant to imaging in DLB and PDD, tabulated the data and summarised the relevant findings. I thought that this could be a useful reference paper particularly for consideration of diagnostic criteria.
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