How to Distinguish Dementia with Lewy Bodies from Alzheimer Disease

Dementia with Lewy (DLB) bodies is the most common type of degenerative dementia after Alzheimer Disease (AD). Although an accurate diagnosis of DLB is important for adequate prognosis and therapy, its differentiation from other dementias and, especially, from AD may be extremely challenging for clinicians, as highlighted by the high variability in reported sensitivity (0.22 - 0.83) and specificity (0.79 - 1.00) rates for a diagnosis of probable DLB applying current clinical criteria. Various kinds of imaging procedures, including conventional MRI and brain perfusion SPECT, have been proposed for improving diagnostic accuracy, especially for most controversial cases. Among such techiques, those using radioactive tracers measuring the striatal binding at pre-synaptic dopamine transporter sites or myocardial uptake in post-ganglionic sympathetic fibers have emerged as the most useful for diagnostic purposes.