Relationship between White Matter Lesions and Progression of Cognitive Decline in Alzheimer's Disease

This study examined the relationship between baseline white matter lesions (WMLs) and the progression of cognitive decline in patients with late-onset Alzheimer's disease (AD).

Fifty-six patients with AD were included in the study (23 men, 33 women; mean age, 77.8 years). All subjects were treated with acetylcholinesterase inhibitors and followed up for approximately 1 year. The Mini-Mental State Examination (MMSE) score was assessed at least twice to evaluate the progressive cognitive impairment. All subjects underwent brain MRI at baseline and were divided into WMLs(-), mild WMLs(+), and moderate WMLs(+) groups based on WML severity. Changes in MMSE scores between baseline and follow-up were analyzed using the Wilcoxon signed-rank test.

MMSE scores at baseline did not differ significantly among the three groups (p = 0.1658), whereas MMSE scores at the follow-up evaluation were significantly lower in the moderate WMLs(+) group than in the WMLs(-) group (p = 0.0257). The mean MMSE scores remained above baseline values during the approximately 1-year follow-up in the WMLs(-) group, whereas they were decreased in the mild and moderate WMLs(+) groups. Moreover, the frequency of improvement in patients from the WMLs(-) group tended to be higher than that in patients from the WMLs(+) groups.

Baseline WMLs may be associated with the heterogeneous progression of cognitive decline in patients with AD.