Abstract
BACKGROUND: Multiple sclerosis (MS) is an autoimmune neurodegenerative disease with a higher prevalence in women. While puberty appears to act as a trigger for MS, menopause has no clear effects on disease progression. Many studies have shown that transcranial magnetic stimulation (TMS) is a potential antioxidant treatment for MS, but the sexual hormones have been identified as a potential factor affecting TMS response by affecting cortical excitability and possibly clinical outcomes. METHODS: The aim of this study was to test the effect of estrogen, progesterone, and testosterone hormonal supplementation as adjuvants to TMS treatment of experimental autoimmune encephalomyelitis (EAE), an experimental model of MS. The effects of the three hormones were also tested as replacement therapy in ovariectomized rats treated with TMS. Clinical signs of the disease, as well as disease-induced oxidative stress and antioxidant defenses of the glutathione system, were evaluated. RESULTS: TMS alone, without supplements or replacement therapies, is effective against oxidative stress caused by EAE. Estrogen and progesterone replacement therapy is useful to enhance the role of TMS in ovariectomized rats, activating antioxidant defenses and improving clinical signs of the disease. CONCLUSIONS: TMS is effective in the treatment of MS, but its role could be enhanced, using hormone replacement therapy with estrogens and/or progesterone.