The role of transcranial magnetic stimulation in the diagnosis of dementia

Transcranial magnetic stimulation (TMS) is a safe, noninvasive, and powerful tool to assess specific cortical circuits in the central nervous system. Over the past two decades, the use of TMS in clinical neurophysiology, neurology, neuroscience, and psychiatry has spread widely, leading to important findings on cortical excitability, plasticity and connectivity in different forms of dementia, providing objective biomarkers of disease pathophysiology and predictors of cognitive decline. More recently, TMS has been successfully employed in the classification of Alzheimer's disease, frontotemporal dementia and atypical Parkinsonism. The objective of the present chapter is to examine the utility of TMS as a means to support and predict the clinical diagnosis of the most common neurodegenerative dementias, foreshadowing the need for non-invasive and low-cost biomarkers in view of the advent of novel disease modifying treatments.