Neuroanatomical Characteristics Associated With Response to Deep Brain Stimulation of the Nucleus Basalis of Meynert for Alzheimer's Disease

Abstract

Objectives: First reports on the application of deep brain stimulation (DBS) of the Nucleus basalis of Meynert (NBM) showed feasibility and safety of the intervention in patients with Alzheimer´s disease. However, clinical effects vary and the mechanisms of actions are still not well understood. The aim of this study was to characterize neuroimaging changes that are associated with the responsiveness to the treatment.

Materials and methods: We examined preoperative T1-weighted MR images of ten patients with Alzheimer's disease (AD) treated with DBS of the NBM and correlated the clinical outcome with volumetric differences of cortical thickness. Subsequently, we sought to identify brain regions that carry out the clinical effects by correlating the outcome with streamlines connected to the volume of activated tissue. Clinical assessments at baseline, 6 and 12 months after the intervention included the AD Assessment Scale as well as the mini mental status examination.

Results: A fronto-parieto-temporal pattern of cortical thickness was found to be associated with beneficial outcome. Modulation of streamlines connected to left parietal and opercular cortices was associated with better response to the intervention.

Conclusion: Our results indicate that patients with less advanced atrophy may profit from DBS of the NBM. We conclude that beneficial effects of the intervention are related to preserved fronto-parieto-temporal interplay.

Keywords: Alzheimer's disease; Nucleus basalis of Meynert; cortical thickness; deep brain stimulation.