**2. Current treatment pathways**

Parkinson's disease is a degenerative disease of the nervous system. The exact cause for Parkinson's disease is not well understood. There is no definitive test for PD – diagnosis is often based on medical history and the presence of the classic symptoms and signs of PD (Samii et al. 2004; Tolosa & Katzenschlager, 2007). Sometimes people are given anti-PD drugs to see if they respond, or other tests may be performed, such as MRI and CAT scans, to rule out other disorders with similar symptoms (Gelb et al. 1999; Hughes et al. 2002). The presence of other diseases, such as dementia and general ageing can obscure PD symptoms and reduce the chance of an accurate diagnosis. Certain drugs, when taken for long periods of time or in amounts greater than recommended, can cause Parkinsonism (Di Fabio et al. 2013) and have side effects. These medications do not result in Parkinson's disease, however, and symptoms resolve when the medications are no longer used.

**4. Oxidative stress and Parkinson's disease**

**5. Selenium and other antioxidants in Parkinson**

time, can cause harm in ways that we are just beginning to understand.

(Ambani et al. 1975).

Oxidative stress could play an important role in the degenerative process leading to Parkin‐ son's disease. These considerations provide a rationale for therapeutic strategies to diminish oxidative stress in dopaminergic regions of brain. If oxidative stress is a major factor, the agents that selectively and safely chelate iron may be of value. It was reported that the mitochondrial deficiency (Shoffner et al. 1991; Jenner, 1991; Saggu et al. 1989; Perry & Yong, 1986) in electron transport, enhanced lipid peroxidation, elevated superoxide dismutase, diminished capacity to remove excess hydrogen peroxide (suggested by low glutathione and glutathione peroxi‐ dase levels) and the presence of increased iron, which catalyses formation of highly reactive hydroxyl ions from hydrogen peroxide, make attractive the suggestion that oxidative stress could play an important role in the degenerative process leading to Parkinson's disease

Possible Relation Between Trace Element Status and Clinical Outcomes in Parkinson Syndrome

http://dx.doi.org/10.5772/57612

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Deficiency of the minerals and other antioxidants required for life are relatively uncommon, however, modest deficiency is very common and often not taken seriously. Selenium is an essential trace element which is necessary for growth and protein synthesis. Selenium protects cellular elements from oxidative damage and may participate in redox type reactions. Low plasma selenium concentrations are associated with subtle neurological impairments reflected in soft neurological signs (Shahar et al. 2010). A statistically significant increase in plasma Se was identified for PD patients (McIntosh et al. 2012). This has been evidenced by an increased lipid peroxidation and reduced glutathione levels (Delanty and Dichter, 2000) and high concentration of iron and free radical generation via autocatalytic mechanisms within neuro‐ melanin-containing catecholaminergic neurons in the substantia nigra. In addition, the observation that exogenous administration of cysteine, N-acetyl cysteine or glutathione decreased the neurotoxic effects of 6-hydroxydopamine in vitro and in vivo reinforces this hypothesis (Soto-Otero et al. 2000). McCann et al. (2011), tested whether selenium-dependent proteins that are essential from an evolutionary perspective are more resistant to selenium deficiency than those that are less essential. The authors demonstrated a highly sophisticated array of mechanisms at cellular and tissue levels that, when selenium is limited, protect essential selenium-dependent proteins at the expense of those that are nonessential. It was also found that mutations in selenium-dependent proteins that are lost on modest selenium deficiency result in characteristics shared by age-related diseases including cancer, heart disease, and loss of immune or brain function (McCann et al., 2011). It was concluded that taking a multivitamin that contains selenium is a good way to prevent deficiencies that, over
