BRAIN MERCURY IN NEURODEGENERATIVE DISORDERS

Background: Trace element neurotoxicity has long been invoked as an et iologic factor for Alzheimer's disease. This study was conducted to de termine the concentrations of mercury in seven different brain regions from deceased patients histologically confirmed with Alzheimer's dise ase or multiple sclerosis as compared to control subjects without know n central nervous system and renal disorders. Brain mercury concentrat ions in all deceased subjects can arise From amalgam restorations, die t, and the working environment. Methods: Autopsy frozen specimens (con trol, Alzheimer's disease and multiple sclerosis) from seven brain reg ions, which included frontal cortex, temporal cortex, occipital cortex , putamen, hippocampus, corona radiata and corpus callosum were assaye d for the concentrations of selenium using instrumental neutron activa tion analysis and mercury using radiochemical neutron activation analy sis. Results: We found that the concentrations of mercury and the merc ury/selenium molar ratios were significantly lower in the hippocampi o f multiple sclerosis patients as compared to aged-matched controls. Ho wever, no statistically significant differences were detected for the concentrations of mercury mercury and the mercury/selenium molar ratio s for the remaining six brain regions among these groups. Conclusions: Since brain mercury concentrations from deceased subjects with either Alzheimer's disease or multiple sclerosis are not significantly highe r than controls, the present study provides no scientific support that mercury plays a significant role in the pathogenesis of these neurolo gic disorders.