The nature of the parkinsonism-dementia complex and amyotrophic lateral sclerosis of Guam and magnesium deficiency.

The parkinsonism-dementia complex (PDC) and amyotrophic lateral sclerosis (ALS) were the fatal neurological diseases, showing very high incidence during 1950-1970 and dramatic decrease after 1970 on Guam. Through the research, the present author insisted that; (1) NFTs in Guam ALS patients are merely a background feature widely dispersed in the population, (2) Guam ALS and PDC are basically different diseases, and (3) Guam ALS occurs initially as classic ALS. As pathogeneses of the diseases, intake of low calcium (Ca) and magnesium (Mg) and high aluminum water and of some plant excitatory neurotoxin has been speculated. To elucidate the pathogenesis, the author performed an experiment exposing rats to low Ca and/or Mg intake for two generations, so as to follow the actual way of human living on the island, since several generations live continuously in the same environment. The study indicates that continuous low Mg intake for two generations induces exclusive loss of dopaminergic neurons in in rats, and may support the Mg hypothesis in the pathogenesis of PDC of Guam.