Dementia with Lewy Bodies and Functional Magnetic Resonance Imaging Application

Dementia with Lewy bodies (DLB) accounting for approximately 10%-20% of dementia cases, and this makes DLB the second most common type of dementia among neurodegenerative diseases. One of the neuropathological hallmarks of DLB is the presence of Lewy bodies, which mainly consist of alphasynuclein aggregates. However, a mixed pathology with other neurodegenerative dementias is common, which increases the possibility of misdiagnosis. Risk signs such as rapid eye movement sleep behavior disorder (RBD), and anosmia have been identified, and core and supportive clinical features such as cognitive fluctuations, visual hallucinations, parkinsonism, and RBD were proposed. Different biomarkers with nuclear medicine imaging, electrophysiological recording, and structural magnetic resonance imaging can help differentiate DLB from other neurodegenerative dementias, but to date, functional magnetic resonance imaging (fMRI) has not been considered as a valid biomarker. The applications of resting-state and task-related fMRI on DLB were reviewed in this study. Due to the clinical features of DLB, such as attention deficits and visual hallucinations, fMRI can observe functional connectivity differences and activity differences through well-designed stimulations between DLB and controls, making fMRI a promising technique for DLB diagnosis.