Identifying the neurostimulation target for treatment of cognitive impairment in aging and early cerebral small vessel disease

Abstract

To develop individualized approaches to the use of neuromodulation as a non-pharmacological treatment of cognitive impairment (CI) based on the assessment of compensatory brain reserves in functional MRI (fMRI). Twenty-one adults over 45 years of age, representing a continuum from healthy norm to mild cognitive impairment due to aging and early cerebral small vessel disease, were studied. All participants underwent fMRI while performing two executive tasks - a modified Stroop task and selective counting. To assess the ability to compensate for CI in real life, functional activation and connectivity were analyzed using the BRIEF-MoCA score as a covariate, which is the difference in ratings between the Behavior Rating Inventory of Executive Function (BRIEF) and the Montreal Cognitive Assessment Scale (MoCA). Both fMRI tasks were associated with activation of areas of the frontoparietal control network, as well as supplementary motor area (SMA) and the pre-SMA, the lateral premotor cortex, and the cerebellum. An increase in pre- SMA connectivity was observed during the tasks. The BRIEF-MoCA score correlated firstly with connectivity of the left dorsolateral prefrontal cortex (DLPFC) and secondly with involvement of the occipital cortex during the counting task. The developed technique allows identification of the functionally relevant target within the left DLPFC in patients with CI in aging and early cerebral microangiopathy.