Clinical Manifestations

Area of Science:

• Neurology
• Neuroscience
• Cognitive Science

Background:

• The prodromal stage of dementia with Lewy bodies (pro-DLB) is recently defined, but its neuropsychological and neuroimaging profile across different clinical onsets remains under-investigated.
• Understanding these profiles is crucial for early diagnosis and differentiating pro-DLB from other neurodegenerative conditions like Alzheimer's disease (AD).

Purpose of the Study:

• To clarify the specific neuropsychological and neuroimaging markers differentiating pro-DLB from mild cognitive impairment due to AD (MCI-AD).
• To investigate how clinical onset (MCI-DLB, psychiatric-onset, delirium-onset) influences these markers in pro-DLB.

Main Methods:

• A cohort of 26 pro-DLB patients (including MCI-DLB, psychiatric-onset, and delirium-onset) and 15 MCI-AD patients underwent comprehensive neuropsychological assessments.
• Structural MRI and Voxel-Based Morphometry (VBM) were used to compare gray matter volume differences between pro-DLB, MCI-AD patients, and healthy controls.

Main Results:

• Pro-DLB patients demonstrated significant deficits in alertness, working memory, visuospatial processing, abstract reasoning, and planning compared to MCI-AD.
• Neuropsychiatric symptoms such as anxiety and hallucinations were more prevalent in pro-DLB.
• Brain imaging revealed increased atrophy in occipital, parietal, and frontal regions, including the nucleus accumbens, with relative preservation of the medial temporal lobe in pro-DLB compared to MCI-AD.

Conclusions:

• The neuropsychological profile of pro-DLB is characterized by deficits in visuospatial abilities, executive functions, and attention, consistent with the full-blown disease.
• Neuroimaging findings correlate with observed cognitive and neuropsychiatric symptoms, supporting distinct regional atrophy patterns in pro-DLB phenotypes.
• Targeted neuropsychological assessments focusing on these domains are recommended for accurate pro-DLB identification.