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Neuroimaging in Nuclear Medicine
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
Anne Larsson Strömvall, Susanna Jakobson Mo
Lewy-body dementia (LBD) is a neurodegenerative disorder that shares the features of both Alzheimer´s disease and Parkinson’s disease with the formation of both amyloid plaques and Lewy body inclusions in the brain. Patients with LBD develop both cognitive impairment and Parkinsonism. In Lewy body dementia, there is both a dopamine deficit and a reduction of metabolism in the parietal and temporal lobes. In addition, often the occipital metabolism is affected.
Identifying stage of Alzheimer disease using multiclass particle swarm optimisation technique
Published in Journal of Experimental & Theoretical Artificial Intelligence, 2018
In early AD, intra-neuronal filamentous deposits, or neuro fibrillary tangles (NFTs), accumulate within neurons. These deposits are composed of hyper phosphorylated tau-protein (Shiino et al., 2006). This cellular pathology disrupts axonal transport and induces widespread metabolic decline. The resulting neuronal loss is observable as gross atrophy with MRI. Temporoparietal association cortices and the medial temporal lobe are severely atrophied in AD (DeCarli, 2000), with the entorhinal cortex and hippocampus the earliest and most severely affected (Janke et al., 2001; Thompson et al., 2001). Profound atrophy is also observed in the posterior cingulate gyrus and adjacent precuneus. Specific atrophic patterns differentiate AD from frontotemporal, semantic, and Lewy body dementias (Paling et al., 2001; Studholme et al., 2001). Patients with AD show minimal primary visual, sensorimotor, and frontal atrophy until late in the disease. Before symptom onset in AD, and also in those at genetic risk, grey matter loss is detectable in the anterior hippocampal/amygdala region (Lehtovirta, Laakso, Frisoni, & Soininen, 2000; Reiman et al., 2001). Atrophying grey matter (Lˇders., Steinmetz1, & Jncke, 2002) is a sign of the progression of Alzheimer’s disease and other forms of dementia. Atrophy in the grey matter is shown as the amount of grey matter shrinks in the imaging tests (Douaud et al., 2013).