Delineating dementia with lewy bodies: can magnetic resonance imaging help?

As future treatments increasingly target the protein chemistry underlying the different dementias, it becomes crucially important to distinguish between the dementias during life. Neither specific protein nor genetic markers are as yet available in clinical practice. However, neuroimaging is an obvious candidate technique that may yield enhanced diagnostic accuracy when applied to the dementias. The physiopathology and anatomopathology is complex in dementia with Lewy bodies (DLB). Besides the relative sparing of medial temporal lobe structures in DLB in comparison to Alzheimer's disease, no clear signature pattern of cerebral atrophy associated with DLB has been established so far. Among others, one reason may be the difficulty in visualizing the small brain nuclei that are differentially involved among the dementias. While we think that structural magnetic resonance imaging neuroimaging should be part of the diagnostic workup of most dementia syndromes due to its usefulness in the differential diagnosis, its contribution to a positive diagnosis of DLB is as yet limited. The development of different neuroimaging techniques may help distinguish reliably DLB from other neurodegenerative disorders. However, in order to become accepted as part of standard care, these techniques must still prove their effectiveness under routine conditions such as those encountered by the general practitioner.