Deep Brain Stimulation as a Tool for Improving Cognitive Functioning in Alzheimer’s Dementia: A Systematic Review

Abstract

Deep brain stimulation (DBS) is an established, in selected cases therapeutically effective, non-lesional treatment method delivering current rectangular pulses into dysfunctional brain structures via chronically implanted stimulation electrodes. DBS is a recognized method applied in movement disorders and is increasingly evaluated as a possible therapeutic option for psychiatric diseases such as refractory obsessive-compulsive disorders, Gilles de la Tourette syndrome, major depression, and substance-related addiction. Latest research indicates that DBS may be a method for improving cognitive functions in Alzheimer’s dementia (AD). Translational data in healthy and AD animals appear to support this notion. Nevertheless, many aspects remain unclear, particularly with regard to the optimal target structure. The objective of this review is to present a systematic overview regarding published research on DBS and cognitive functioning in animal and human studies as well as to provide a systematic overview of the feasibility and efficacy of the treatment. We describe three studies investigating the effects of DBS in patients with dementia, using either the fornix or the nucleus basalis of Meynert (NBM) as a target. In total, we identified 25 animal studies with 10 brain structures being targeted: fornix, NBM, anterior caudate nucleus, dorsal striatum, anterior thalamic nucleus, midline thalamic nuclei, central thalamus, lateral hypothalamus, hippocampus (entorhinal cortex, perforant path), and amygdala. Considering the wide and diverse spectrum of targets, we add to this review a supposition about possible underlying mechanisms of operation and recommendations for further research.

Neuropsychiatric Effects of Subthalamic Nucleus Deep Brain Stimulation in Parkinson Disease in China: A Prospectively Controlled Study

“…Stimulation at the site of NBM markedly improved various aspects of cognitive functions by enhancing cholinergic innervation to the cortex [33]. Other stimulation targets include fornix, amygdala, rhinal cortex, hippocampus, pedunculopontine tegmental nucleus and entorhinal cortex as to indicate an alternative way to cope with cognitive disorders in clinical practice [34].…”

Chemical and Physical Approaches for the Treatment of Alzheimer's Disease

“…It triggers θ-phase resetting and the release of ACh, the necessary condition of long-term potentiation (LTP) [14]. One study investigated whether perforant path DBS intervened with the circuits related to encoding and retrieving the information of the received stimuli in the working memory task [146].…”

Neuroradiology, Anesthesia, Bioengineering, and Hardware Programming in the Clinical Applications of Deep Brain Stimulation

“…Deep brain stimulation offers a method by which a surgeon may affect neuronal discharge patterns within the vicinity of the target, as well as in distant regional sections of the brain, via conveying bioelectric impulses along trajectories that originate in the target area and spread to remote neuronal structures [1]. In DBS, stereotactically-guided electrodes are placed within a predefined target structure in the brain, and electrical stimulation of these electrodes pulses specific neurons causing a bioelectrical effect in the targeted brain cells.…”