Background:
Impaired clinical insight is common in cognitive impairment and poses challenges for patient management and counselling. White matter disease (WMD) has been implicated in cognitive dysfunction, but its relationship with insight remains unclear.
Methods:
We conducted a retrospective analysis of 134 clinic patients (mean age 75.8 years) with cognitive impairment. WMD severity was rated using the Fazekas scale by two independent radiologists and categorized into deep white matter (DWM), periventricular white matter (PVWM), and total WMD. Associations between Clinical Insight Rating Scale (CIRS) and WMD were examined using multivariate regression adjusting for age, Functional Assessment Staging Tool (FAST) stage, and medial temporal atrophy (MTA) scores. Path analysis was used to explore direct and indirect mediating effects via cognitive domains.
Results:
Both DWM (β = 0.304) and total WMD (β = 0.153) were associated with impaired insight, while PVWM was not. The domain of judgement was strongly associated with insight (β = 1.743). Path analysis showed that DWM was indirectly associated with impaired insight through judgement (DWM → judgement β = 0.280; judgement → insight β = 0.508), with a weaker but significant direct effect of DWM on insight (β = 0.158).
Conclusion:
DWM disease contributes to impaired insight, mediated through its impact on judgement, and remains significant after accounting for age, FAST and MTA. These findings suggest structural brain changes in DWM may underlie deficits in insight, highlighting the need for clinicians to anticipate counselling challenges in patients with DWM disease.