The following is a summary of “White Matter Hyperintensity Trajectories in Patients With Progressive and Stable Mild Cognitive Impairment,” published in the August 2023 issue of Neurology by Kamal et al.
White matter hyperintensities (WMH) are brain changes linked to aging and cognitive decline. The link between WMH and amyloid positivity, dementia, and mild cognitive impairment (MCI) is still unclear. Examining whether changes in WMH burden over time differ in amyloid-negative (Aβ−) and amyloid-positive (Aβ+) individuals with MCI who remain stable or convert to dementia.
Researchers performed a retrospective study comparing regional WMH burden among four groups: Aβ+ progressors, Aβ− progressors, Aβ+ stable individuals, and Aβ− stable individuals.
They analyzed participants with MCI from the Alzheimer’s Disease Neuroimaging Initiative. Those with available APOE ɛ4 status and amyloid measures for determining amyloid status (Aβ+ or Aβ−) were included. Encompassed individuals with a baseline MCI diagnosis, APOE ɛ4 data, and amyloid measurements. Across 13 years, the analysis involved 5.7 follow-up time points per participant, totaling 5,054 follow-up time points.
The results showed 820 subjects (55 to 90 years) with Aβ+ progressors (n = 239), Aβ− progressors (n = 22), Aβ+ stable individuals (n = 343), and Aβ− stable individuals (n = 216). Individuals who remained Aβ− stable displayed lower baseline WMH levels compared to both Aβ+ progressors and Aβ+ stable individuals across regions of interest (β range: 0.20–0.33, CI range: 0.03–0.49, P<0.02), except for deep WMH. Over time, all groups showed a sharper rise in WMH burden than Aβ-stable individuals. Among them, Aβ+ progressors had the most substantial rise (β range: −0.03 to 0.06, CI range: −0.05 to 0.09, P<0.01), indicating the highest accumulation of WMH over time.
They concluded that WMH accumulation contributes to conversion to dementia in older adults with MCI, regardless of amyloid status.