Abstract
Background: The assessment of early and subtle cognitive and behavioral
effects of cerebral small vessel disease (SVD) requires specific and long-lasting
evaluations performed by experienced neuropsychologists. Simpler tools would be helpful
for daily clinical practice.
Objective: To determine whether a simple reaction time task that lasts 5
minutes and can be performed without external supervision on any tablet or laptop can be
used as a proxy of early cognitive and behavioral alterations in CADASIL (Cerebral
Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy), a
monogenic form of pure SVD related to NOTCH3 mutations.
Methods: Twenty-two genetically confirmed patients with CADASIL having
preserved global cognitive abilities and without disability (MMSE >24 and modified
Rankin’s scale ≤1) were compared to 29 age-and-gender matched controls to determine group
differences according to: 1) conventional neuropsychological and behavioral testing; 2) a
computerized battery evaluating reaction time, processing speed, and executive functions.
In a second step, correlations between reaction time and cognitive and behavioral
alterations detected using both conventional and computerized testing were tested in
patients.
Results: Reaction time was significantly higher in patients than in controls
(mean in patients: 283 ms – in controls: 254 ms, p = 0.03). In patients,
reaction time was significantly associated with conventional and chronometric tests of
executive functions, working memory, and apathy.
Conclusion: Reaction time obtained using a very simple task may serve as a
proxy of early cognitive and behavioral alterations in SVD and could be easily used in
daily clinical practice.
