Authors: Sean J Colloby John D Fenwick David E Williams Sean M Paling Kyriakos Lobotesis Clive Ballard Ian McKeith John T OBrien
Publish Date: 2002/03/05
Volume: 29, Issue: 5, Pages: 615-622
Abstract
Differences in regional cerebral blood flow rCBF between subjects with Alzheimers disease AD dementia with Lewy bodies DLB and healthy volunteers were investigated using statistical parametric mapping SPM99 Fortyeight AD 23 DLB and 20 agematched control subjects participated Technetium99m hexamethylpropylene amine oxime HMPAO brain singlephoton emission tomography SPET scans were acquired for each subject using a singleheaded rotating gamma camera IGE CamStar XR/T The SPET images were spatially normalised and group comparison was performed by SPM99 In addition covariate analysis was undertaken on the standardised images taking the Mini Mental State Examination MMSE scores as a variable Applying a height threshold of P≤0001 uncorrected significant perfusion deficits in the parietal and frontal regions of the brain were observed in both AD and DLB groups compared with the control subjects In addition significant temporoparietal perfusion deficits were identified in the AD subjects whereas the DLB patients had deficits in the occipital region Comparison of dementia groups height threshold of P≤001 uncorrected yielded hypoperfusion in both the parietal Brodmann area BA 7 and occipital BA 17 18 regions of the brain in DLB compared with AD Abnormalities in these areas which included visual cortex and several areas involved in higher visual processing and visuospatial function may be important in understanding the visual hallucinations and visuospatial deficits which are characteristic of DLB Covariate analysis indicated group differences between AD and DLB in terms of a positive correlation between cognitive test score and temporoparietal blood flow In conclusion we found evidence of frontal and parietal hypoperfusion in both AD and DLB while temporal perfusion deficits were observed exclusively in AD and parietooccipital deficits in DLB
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