**3.6 Imaging of dementia with Lewy bodies**

Dementia with Lewy bodies (DLB) is a common Parkinsonian neurodegenerative dementia that is characterized by the development of α-synuclein positive Lewy body neuronal inclusions in the cortex, substantia nigra and brainstem. Patients with DLB, suffer from progressive cognitive decline including memory loss, visual hallucinations, cognitive circadian fluctuations and sleep disorders. In FDG PET of DLB patients, unique hypometabolism in the medial and lateral occipital lobes is observed, and is the feature that distinguishes DLB from AD (Ishii, 2002). DLB can also be distinguished from AD using [18F]DOPA PET. Dopamine deficiencies, similar to PD, have been observed in DLB patients, but not in AD patients (Hu, et al., 2000).
