Abstract WMP116: Incidental Diffusion-weighted Imaging Lesions In Patients With Cognitive Decline
Objectives: Incidental diffusion-weighted imaging (DWI) hyperintense lesions on MRI, indicative of incident silent infarcts, are not uncommon in patients with advanced cerebral small vessel disease (SVD). SVD has been increasingly recognized as playing an important role in cognitive decline in the elderly. We thus examined the prevalence and associated risk factors for DWI hyperintense lesions in a cohort of patients followed in a memory clinic.
Methods: We retrospectively analyzed MRI scans from 251 patients (43% females, mean age 73.3±8.3) with cognitive impairment enrolled in an ongoing prospective longitudinal study at the Massachusetts Alzheimer’s Disease Research Center (MADRC) between 2001 and 2010. Clinical and demographic data including the presence of specific vascular risk factors and degree of cognitive impairment (as measured by the Clinical Dementia Rating (CDR) Scale) were recorded. DWI and apparent diffusion coefficient (ADC) images were inspected for the presence of DWI-hyperintense lesions. Associated MRI markers of SVD including white matter hyperintensities (WMH), whole-brain mean global ADC, cerebral microbleeds (CMB) and lacunar infarcts were quantified.
Results: We identified 16 DWI-hyperintense lesions in 13 (5.2%) patients. The 14 individuals with at least one DWI lesion did not differ from the 237 without lesions by age, gender, vascular risk factors, CDR, moderate to severe WMH, mean global ADC or number of CMB (p>0.05). Assuming a 10-day post-stroke period when DWI lesions remain hyperintense, their estimated annual prevalence would be 2.3 new infarcts per person-year.
Conclusions: Incident DWI-hyperintense lesions, consistent with subacute cerebral infarcts, are not uncommon in unselected patients with cognitive decline. These lesions do not appear to be associated with other markers of SVD nor with degree of impairment. Our results suggest that the cumulative lifetime burden of these lesions may be substantial. These findings may support a role for small infarcts in age-related cognitive impairment.
- © 2012 by American Heart Association, Inc.