Incidence of Amyotrophic Lateral Sclerosis and of the Parkinsonism-Dementia Complex of Guam, 1950–1989

Abstract

Studies representing the accumulated information from the first 30 years of research effort on Guam (1950–1979) have demonstrated a varying degree of decline in the incidence of amyotrophic lateral sclerosis (ALS) and the parkinsonism-dementia complex (PDC) of Guam. Analysis with more complete information for the period 1980–1989 provides more valid estimates of the later patterns in the incidence of ALS and PDC and affords a more extensive assessment of trends over a 40-year period. The annual age-adjusted incidence of ALS was 7/100,000 and the annual age-adjusted incidence of PDC was 22/100,000 in 1989. The incidence was much higher for the period 1980–1989 than suggested in previous reports. These findings provide compelling evidence that this spectrum of neurodegenerative diseases continues to have a significant impact on the health of the Chamorro people of Guam.

Geographical Clustering of Amyotrophic Lateral Sclerosis in South-East England: A Population Study

“…Globally, unusually high incidences are recorded around the Pacific rim, on Guam [12] , the Kii peninsula in Japan [13] , in the Papua (formerly Irian Jaya) province of Indonesia and on the island of Groote Eylandt in north-east Australia [14] . A US population was found to show a geographical gradient of ALS, with higher mortality ratios west of the Mississippi compared to regions to the east [15,16] , and a study in Wisconsin found a significant cluster in the north-east corner of the state [11] .…”

Quantitative Proteomics Identifies Surfactant-Resistant α-Synuclein in Cerebral Cortex of Parkinsonism-Dementia Complex of Guam but Not Alzheimer's Disease or Progressive Supranuclear Palsy

“…10 -13 In contrast, the same reports that showed profound reductions in the incidence of ALS observed less dramatic and sometimes no reduction in the incidence of PDC on Guam 10 -13 and an increase in the average age of onset by ϳ10 years. 12,14,15 Indeed, the most recent studies that used registry data as well as an extensive village public health network on Guam show that, unlike ALS, the incidence of PDC declined only slightly throughout the period of 1940 to 2000. 16 Several environmental initiators, promoters, or suppressors have been proposed to explain these demographic changes (reviewed by Wiederholt PDC is classified histopathologically as a tauopathy, a group of neurodegenerative diseases that share in common abnormal tau-immunoreactive structures in different brain regions.…”

Introductory Chapter: Introduction to Update in Amyotrophic Lateral Sclerosis and Review of this Condition in Sportsmen

“…Other authors said that the only really consistent epidemiological risk factors for ALS are increasing age, male sex and a family history of ALS [24][25][26][27][28] and we agree on that. Even in Guam, where a restricted population with high risk of developing ALS has been under intense scrutiny for over 50 years, controversy persists and no environmental (or genetic) causes have been identified beyond doubt [23,[29][30][31]. On the other hand, cigarette smoking may also be a risk factor [27,28,32] but other information should be taken into consideration.…”