Essential feature of the neuropathological findings in ALS of Guam
The amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC) were the fatal neurological diseases, showing very high incidence during 1945-1965 and dramatic decrease after 1970 on Guam. Based on the findings obtained, it is proposed that (a) NFTs in ALS of Guam are merely a background feature widely distributed in this population, (b) Guam ALS occurs initially as classic ALS, (c) ALS-PDC mixed patient is a case combined with classic ALS and neurofibrillary degeneration, (d) thus a subtype of "Guam ALS" is not present, (e) PDC and ALS of Guam are basically different diseases, and (f) PDC is a discrete disease entity.