Clinical associations of T2-weighted lesion load and lesion location in small vessel disease: Insights from a large prospective cohort study

Abstract Background Subcortical T2-weighted (T2w) lesions are very common in older adults and have been associated with dementia. However, little is known about the strategic lesion distribution and how lesion patterns relate to vascular risk factors and cognitive impairment. Aim The aim of this study was to analyze the association between T2w lesion load and location, vascular risk factors, and cognitive impairment in a large cohort of older adults. Methods 1017 patients participating in a large prospective cohort study (INtervention project on cerebroVAscular disease and Dementia in the district of Ebersberg, INVADE II) were analyzed. Cerebral T2w white matter and deep grey matterlesions, the so-called white matter hyperintensities(WMHs), were outlined semi-automatically on fluid attenuated inversion recoveryimages and normalized to standard stereotaxic space (MNI152) by non-linear registration. Patients were assigned to either a low-risk or a high-risk group. The risk assessment considered ankle brachial index, intima media thickness, carotid artery stenosis, atrial fibrillation, previous cerebro-/cardiovascular events and peripheral artery disease as well as a score based on cholesterol levels, blood pressure and smoking. Separate lesion distributions were obtained for the two risk groups and compared using voxel-based lesion-symptom mapping. Moreover, we assessed the relation between lesion location and cognitive impairment (demographically adjusted z-scores of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological AssessmentBattery Plus, CERAD-NAB Plus) using voxel-based statistics (α = 0.05). Results A total of 878 out of 1017 subjects (86%) had evaluable MRI data and were included in the analyses (mean age: 68.2 ± 7.6 years, female: 515). Patients in the high-risk group were characterized by a significantly higher age, a higher proportion of men, a higher lesion load (p  Conclusion Age, gender, several cognitive scores, and WMH lesion load were shown to be significantly associated with vascular risk factors in a population of older, but cognitively preserved adults. Vascular risk factors seem to promote lesion formation most severely at well-defined locations. While lesion load showed weak associations to some cognitive scores, no focal locations causing specific cognitive disturbances were identified in this large cohort of older adults.