Neuroimaging criteria and cognitive performance in vascular mild cognitive impairment: A systematic review

The recognition of Cerebrovascular Disease (CVD) at earlier clinical stages may favor the control of vascular risk factors and prevention of dementia. However, operational criteria for symptomatic phases at non-dementia stages are often difficult, as the current criteria normally require the evidence of extensive subcortical disease.

To identify the neuroimaging profile of Vascular Mild Cognitive Impairment (VaMCI), the impact of those aspects over cognition and the neuropsychological tests that distinguished VaMCI from other groups.

Searches were performed in Scopus, ISI and PsycINFO, using the following key terms: "vascular mild cognitive impairment" OR "vascular cognitive impairment no dementia" OR "vascular cognitive impairment not demented" OR "subcortical mild cognitive impairment".

Of 249 papers, 20 studies were selected. Ten of those included only patients with severe White Matter Hyperintensities (WMH), whereas 10 others admitted subjects with moderate-to-severe WMH. Both groups showed poor performances in Executive Function (EF) tasks in comparison to normal controls and other diagnostic groups. Among EF tests, those assessing "complex" EF abilities consistently distinguished VaMCI from other groups, regardless of the severity of WMH. VaMCI subjects with severe or moderate-to-severe WMH showed cognitive deficits in comparison with other groups. "Complex" EF tests were the most useful in differentiating those patients from the other groups.

The occurrence of VaMCI may be associated with the presence of CVD at moderate levels; the detection of vascular damage at earlier stages may allow the adoption of therapeutic actions with significant effect-sizes.