Different cognitive profiles between mild cognitive impairment due to cerebral small vessel disease and mild cognitive impairment of Alzheimer’s disease origin

Controversy surrounds the differences of the cognitive profile between mild cognitive impairment resulting from cerebral small vessel disease (MCI-SVD) and mild cognitive impairment associated with prodromal Alzheimer's disease (MCI-AD). The aim of this study was to explore and compare the cognitive features of MCI-SVD and MCI-AD. MCI-SVD patients (n = 56), MCI-AD patients (n = 30), and normal control subjects (n = 80) were comprehensively evaluated with neuropsychological tests covering five cognitive domains. The performance was compared between groups. Tests that discriminated between MCI-SVD and MCI-AD were identified. Multiple cognitive domains were impaired in MCI-SVD group, while memory and executive function were mainly impaired in MCI-AD group. Compared with MCI-SVD, MCI-AD patients performed relatively worse on memory tasks, but better on processing speed measures. The AVLT Long Delay Free Recall, Digit Symbol Test, and Stroop Test Part A (performance time) in combination categorized 91.1% of MCI-SVD patients and 86.7% of MCI-AD patients correctly. Current study suggested a nonspecific neuropsychological profile for MCI-SVD and a more specific cognitive pattern in MCI-AD. MCI-AD patients demonstrated greater memory impairment with relatively preserved mental processing speed compared with MCI-SVD patients. Tests tapping these two domains might be potentially useful for differentiating MCI-SVD and MCI-AD patients.