Relationship of Leukoaraiosis to Cognitive Decline and Cognitive Aging

Abstract

Objective: Leukoaraiosis (LA) is a common finding on MRI scans of the elderly. However, its exact relationship to cognitive decline and dementia is in dispute. Because LA involves the paracallosal white matter, we sought to determine if LA, uncomplicated by ischemic lesions or complaints of cognitive impairment, is associated with cognitive loss or difficulties with interhemispheric integration of behavioral functions.Methods: Two hundred fifty-seven MRI scans with deep white matter changes were screened. After a chart review, 38 patients had uncomplicated LA, and 31 gave informed consent to undergo cognitive and behavioral testing.Results: LA severity was not related to any of the cognitive or behavioral assessments. However, some dependent measures showed medium effect sizes that were in keeping with published findings, indicating that LA has a marginal impact on cognition. In comparison, robust relationships with age were found for certain tasks, suggesting that our cohort size was sufficient to detect meaningful clinical relationships.Conclusion: Based on statistical interpretations using effect sizes, LA severity may be better viewed as a biomarker for physiological brain aging that is in advance of chronological age, leaving the elderly individual at greater risk for developing dementia.A lthough leukoaraiosis (LA) is a common finding on MRI scans, its pathophysiologic significance is not fully understood ( Fig. 1). 1-6 LA is most strongly associated with being elderly. Hypertension, diabetes mellitus, coronary artery disease, smoking, and noncoronary arterial vascular disease are additional risk factors. However, its relationship to normal cognitive aging and dementia is not yet known. 6 Some investigators have suggested that its presence may speed the dementia process. Others have hypothesized that LA is a possible risk factor for both dementia and lacunar stokes. 7 Yet, a study using both functional and static imaging techniques found no relationships between LA severity or presence of lacunar infarcts and either cognitive deficits, brain atrophy, or changes in regional cerebral blood flow or glucose metabolism, whereas changes in regional cerebral blood flow and glucose metabolism appropriately predicted cognitive deficits and brain atrophy. 3 Some studies have been able to show weak associations of LA severity to gait disturbances and selected neuropsychologic assessments, such as the Wisconsin Card Sort Test (WCST), Trail Making Test B, Digit Span Forward, and Mini-Mental State Examination (MMSE), whereas others have not. [8][9][10][11][12][13][14][15][16][17] In a recent meta-analysis of the relationship between LA and cognitive impairment, Gunning-Dixon and Raz 18 found that LA is associated with poorer performance on tasks requiring executive functions, processing speed, delayed memory, and global indices of cognitive functions but not indices involving ''psychometric intelligence.'' However, when reviewing the effect sizes for the significant associations using r 2 values calculated from the pap...

Whole-Brain Histogram and Voxel-Based Analyses of Diffusion Tensor Imaging in Patients with Leukoaraiosis: Correlation with Motor and Cognitive Impairment

“…3,4 The possible correlation of LA with cognitive decline or motor deficit has been investigated using visual or computerized methods to assess the LA extent. [5][6][7][8][9][10][11][12][13][14][15][16] Diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) are MR techniques sensitive to changes in the diffusion properties of water protons in terms of apparent diffusion coefficient (ADC), mean diffusivity (MD), or fractional anisotropy (FA). Previous studies using region of interest measurements have demonstrated that MD and FA in patients with LA are altered not only in the areas exhibiting signal intensity changes in T2-weighted images but also in the normal-appearing white matter.…”

The Auditory Oddball Paradigm in Patients with Vascular Cognitive Impairment: A Prolonged Latency of the N₂ Complex

“…factors. The lack of correlation is not completely surprising since the clinical impact of the severity of white matter lesions on cognition is also under discussion [31,32] . However, we did fi nd a signifi cant correlation between the N 2 latency and the total neuropsychological score, while this was not the case with P 3 .…”

Preliminary Evaluation on Cerebral Small Vascular Disease with Cerebral Arerio-venous Pulse Wave Time

“…The occurrence of LA is closely related to circulation disorder of white matter adjacent to the lateral ventricle wall, cerebrospinal fluid circulation disorders and cerebral edema; temporarily no evidence showed that LA is directly related to atherosclerosis. But LA may result in subcortical infarction and cerebral hemorrhage, and is an independent predictor of stroke [14] ; the more severe white matter lesions, the lower regional cerebral blood flow, the worse cerebral autoregulation [15] , reflecting higher levels of ICAM-1, a blood marker of endothelial damage [16] . When LA with cerebral infarction, cerebral hemorrhage, cerebral micro hemorrhage is the mixed group of this study, representative of severe white matter lesions; So mixed group had more obvious correlation with cerebral arteriosclerosis, but it was not necessary that mild LA was related to cerebral arteriosclerosis.…”