An overview of repetitive transcranial magnetic stimulation (rTMS) in Alzheimer's disease

Background. Alzheimer's disease (AD) is the most frequent neurocognitive disorder. It affects 50% to 75% of the cases of dementia, and is characterized by a progressive cognitive decline that hinders behavior and functionality. Its etiology is still uncertain, and the efficiency of treatments is limited. Repetitive transcranial magnetic stimulation (rTMS) has been used as an alternative therapeutic strategy, but the clinical impact on Alzheimer's disease has hardly been studied. Objective. To describe the effects of rTMS on cognition, the behavioral and psychological symptoms of dementia (BPSD), and functionality, considering the various modes of application. Method. The PubMed, ScienceDirect, and PsycInfo databases were consulted using key words relating to the topic of study. Articles published between 2006 and 2016 were selected. Results. The studies that have assessed the clinical effect of rTMS have used various parameters to stimulate and compare the different cortical areas, principally the dorsolateral prefrontal cortex. A variety of benefits have been proposed for patients with Alzheimer's disease in cognitive domains such as language and episodic memory, as well as behavior and functionality in everyday activities. Discussion and conclusion. rTMS has been suggested as a possible treatment for AD, and the results indicate the need for further studies with different methodological designs and more participants, in addition to cognitive rehabilitation techniques. The objective is to identify the most efficient parameters for stimulation and to explore new cortical targets.