Modelling of the Electric Field Distribution in Deep Transcranial Magnetic Stimulation in the Adolescence, in the Adulthood, and in the Old Age

Journal: Computational and Mathematical Methods in Medicine 9039613 (2016)

Authors: S Fiocchi, M Longhi, P Ravazzani, Y Roth, A Zangen, M Parazzini

Background:

In the last few years, deep transcranial magnetic stimulation (Deep TMS™) has been used for the treatment of depressive disorders,which affect a broad range of age populations, from adolescents to aging people. To facilitate its clinical application, particular shapes of coils, including the so-called Hesed(H)coils, were designed.

Objective:

This paper aims to provide a picture of the distribution of the induced electric field in four realistic human models of different ages and gender.

Methods:

Theelectric field distributions were calculated by using numerical techniques in the brain structures potentially involved in the progression of the disease and were quantified in terms of both amplitude levels and focusing power of the distribution.

Results:

The results highlight how the chosen Hesed coil (H7 coil) is able to induce the maximal levels of E mainly in the prefrontal cortex, particularly for the younger model. Moreover, growing levels of induced electric fields with age were found by going in deep in the brain, as well as a major capability to penetrate in the deepest brain structures with an electric field higher than 50%, 70%, and 90% of the peak found in the cortex.

Conclusions:

This study shows that H7 coil is able to induce levels of electric field in the typical brain target areas for the treatment of depressive disorders comparable with the ones found for other H-family coils. This conclusion is still valid also considering the effect of age.

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