Cognitive heterogeneity among community-dwelling older adults with cerebral small vessel disease

Abstract

Some degree of ischemic injury to white matter tracts occurs naturally with age and is visible on magnetic resonance imaging as focal or confluent white matter hyperintensities. Its relationship to cognition, however, remains unclear. To explore this, community-dwelling adults between the ages 55 and 80 years completed structural imaging, neuropsychological testing, and questionnaires to provide objective measures and subjective experience of executive functioning. Volumetric lesion burden derived from structural MRI identified those with significant white matter hyperintensity burden (∼10 cm3). Half of those recruited met this criterion and were designated as the cerebral small vessel disease (CSVD) group. Subjective cognitive complaints but not objective test scores differentiated adults with and without CSVD. Hierarchical clustering revealed 2 CSVD subgroups that differentiated those with impaired versus preserved executive function relative to controls. Overall these results provide some explanation for behavioral heterogeneity often observed in studies of age-related white matter changes. They also support the use of questionnaires to assess subjective cognitive complaints that may point to subtle effects of vascular pathology not evident on standardized cognitive scores.