Subcortical vascular cognitive impairment, no dementia: EEG global power independently predicts vascular impairment and brain symmetry index reflects severity of cognitive decline.

Background And Purpose: Vascular cognitive impairment, no dementia (vCIND) is a prevalent and potentially preventable disorder. Clinical presentation of the small-vessel subcortical subtype may be insidious, and differential difficulties can arise with mild cognitive impairment. We investigated EEG parameters in subcortical vCIND in comparison with amnestic multidomain mild cognitive impairment to determine the additional diagnostic value of quantitative EEG in this setting.

Methods: Fifty-seven community-residing patients with an uneventful central neurologic history and first presentation of cognitive decline without dementia were included. Neuropsychological test results were correlated with EEG parameters. Predictive values for vCIND and amnestic multidomain mild cognitive impairment were calculated using receiver operating characteristic curves and logistic regression modeling.

Results: Vascular cognitive impairment, no dementia and amnestic multidomain mild cognitive impairment differed with regard to the EEG (delta + theta)/(alpha + beta) ratio (DTABR) and pairwise derived brain symmetry index. We found statistically significant correlations between pairwise derived brain symmetry index and immediate verbal memory, immediate global memory, verbal recognition, working memory, and mean memory score in vCIND. Verbal fluency (odds ratio: 1.54, 95% confidence interval: 1.04-2.28, P = 0.033) and (delta + theta)/(alpha + beta) ratio (odds ratio: 2.28, 95% confidence interval: 1.06-4.94, P = 0.036) emerged as independent diagnostic predictors for vCIND with an overall correct classification rate of 95.0%.

Conclusion: Our data indicate that EEG is of additional value in the differential diagnosis and follow-up of patients presenting with cognitive decline. These findings may have an impact on memory care.