Clinical Manifestations

Area of Science:

• Neurology
• Cognitive Neuroscience
• Geriatrics

Background:

• Impaired insight is a significant challenge in cognitive impairment, affecting diagnosis and care.
• White matter disease (WMD) is linked to cognitive decline, but its specific impact on insight is unclear.
• Understanding the cognitive pathways mediating WMD's effect on insight is crucial.

Purpose of the Study:

• To investigate if white matter disease (WMD) impacts insight in individuals with cognitive impairment.
• To explore the mediating role of cognitive domains in the relationship between WMD and insight.

Main Methods:

• 133 participants with mild cognitive impairment or dementia underwent assessment of white matter hyperintensities (WMH) using the Fazekas scale and insight using the Clinical Insight Rating Scale.
• Structural equation modeling (SEM) was used to analyze direct and indirect pathways between WMH subtypes, cognitive domains, and insight.
• Analyses adjusted for relevant covariates.

Main Results:

• Deep white matter hyperintensities (DWMH), but not periventricular WMH, were associated with poor insight.
• Impaired judgment was strongly linked to poor insight.
• SEM revealed DWMH indirectly affected insight via impaired judgment, with this pathway remaining significant after adjustment.

Conclusions:

• Deep white matter hyperintensities (DWMH) impair insight primarily through their effect on judgment.
• While dementia severity is a strong predictor of insight, the DWMH-judgment link suggests structural changes drive these deficits.
• Disruption of frontal-subcortical circuits by DWM lesions may underlie these findings, necessitating clinical attention to judgment and insight in affected individuals.