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

BACKGROUND: 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). METHODS: 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. RESULTS: 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. CONCLUSION: Baseline WMLs may be associated with the heterogeneous progression of cognitive decline in patients with AD.