Abstract

Background: We have previously demonstrated that brain levels of gamma-aminobutyric acid (GABA) were diminished in patients with various types of dysgeusia and dysosmia by use of magnetic resonance spectroscopy (MRS). We also demonstrated by use of functional magnetic resonance imaging (fMRI) of brain that when these patients were requested to think of their dysgeusia or dysosmia they exhibited significant brain activation in specific brain regions. Treatment with repetitive transcranial magnetic stimulation (rTMS) increased brain levels of GABA as measured by MRS and decreased brain activation as measured by fMRI. These changes were accompanied by increased levels of plasma, erythrocyte and saliva zinc and copper after rTMS.

Purpose: To evaluate if changes in plasma calcium, either in vivo or in vitro, also occurred in these patients after rTMS.

Methods: Measurements of plasma calcium, in vivo and in vitro, were measured in 129 patients with dysgeusia and dysosmia before and after rTMS.

Results: Both in vivo and in vitro levels of plasma calcium increased significantly after rTMS although levels in vivo were higher than in vitro. These changes occurred in both men and women.

Conclusions: These results, as in previous studies with zinc and copper, indicate that electromagnetic fields increase calcium levels. These studies are the first which describe increased levels of plasma calcium both in vivo and in vitro in humans treated with rTMS. These changes are consistent with changes in neuroplasticity that relate to the role that rTMS plays in calcium metabolism related to changes in GABA and other neurotransmitters.

Keywords: Transcranial magnetic stimulation; Calcium; Dysgeusia; Dysosmia; Neuroplasticit