ALS-like disorders of the Western Pacific

Tracie Caller MD MPH (Dr. Caller of Dartmouth-Hitchcock Medical Center has no relevant financial relationships to disclose.)
Matthew Lorincz MD PhD, editor. (Dr. Lorincz of the University of Michigan has no relevant financial relationships to disclose.)
Originally released September 2, 1994; last updated October 21, 2016; expires October 21, 2019

This article includes discussion of ALS-like disorders of the Western Pacific, ALS/PDC, amyotrophic lateral sclerosis-like disorders of the Western Pacific, amyotrophic lateral sclerosis-parkinsonism-dementia complex, Guam neurodegeneration, Lytico-Bodig, Marianas dementia, parkinsonism-dementia-amyotrophic complex of Guam, and PDALS. The foregoing terms may include synonyms, similar disorders, variations in usage, and abbreviations.

Overview

Following World War II, extremely high rates of a neurodegenerative disease with features of amyotrophic lateral sclerosis, dementia, and Parkinson disease were described in the Western Pacific islands of Guam, the Kii peninsula of Japan, and West Papua, Indonesia. Termed “lytico-bodig” by natives, amyotrophic lateral sclerosis-parkinsonism-dementia complex (ALS-PDC) has distinct neuropathologic features of widely distributed neurofibrillary tangles comprised of tau in addition to pathologic findings of amyotrophic lateral sclerosis. Incidence rates have declined dramatically over subsequent decades, with a change in phenotype to predominantly dementia. The etiology of ALS-PDC is most likely a combination of environmental agents coupled with genetic susceptibility.

Key points

 

• Amyotrophic lateral sclerosis-parkinsonism-dementia complex (ALS-PDC), also known as lytico-bodig, is an endemic neurodegenerative disorder of the Western Pacific islands, known to occur only in the islands of the Guam archipelago, the Kii peninsula of Japan, and West Papua, Indonesia.

 

• It is a slowly progressive degenerative disease with a spectrum of clinical presentation that can include features of amyotrophic lateral sclerosis, parkinsonism, and dementia.

 

• The sharp decline in disease prevalence, increasing age of onset, and change in disease phenotype argue for an environmental etiology.

 

• All 3 cultures utilized cycad seeds for medicinal and/or food sources; the cycad-derived toxin cycasin as well as the neurotoxic nonprotein amino acid beta-methyl-amino-L-alanine (BMAA) have been postulated as potential etiologies.

Historical note and terminology

Guam, the largest of the Mariana island archipelago in the Western Pacific, was ceded to the United States by Spain in 1898 after a long history of European colonialism. The island was captured by the Japanese in 1941 during World War II and was recaptured in 1944 and established as an organized territory of the U.S. The military installation on the island is 1 of the most strategically important U.S. bases in the Pacific.

During this time, it was noted that Guam, together with the Kii peninsula of Japan and the Auyu and Jaqai cultural groups of West Papua, Indonesia, had 1 of the highest incidences of amyotrophic lateral sclerosis (ALS), parkinsonism, and dementia in the world (Arnold et al 1953; Kurland and Mulder 1954). This complex of neurodegenerative diseases was termed lytico-bodig by the indigenous Chamorro people of Guam (lytico derived from the Spanish word for weakness, bodig referring to a family with parkinsonism and dementia who worked at a bodega or market), and Moro disease within the Kii peninsula; it is known elsewhere as amyotrophic lateral sclerosis-parkinsonism-dementia complex (ALS-PDC) (Lavine et al 1991). ALS-PDC, or lytico-bodig, has been known to the Chamorro people for over 180 years.

In the 2 decades following WWII, ALS-PDC incidence, prevalence, and mortality rates in the Chamorro population of Guam was 50 to 100 times that of sporadic amyotrophic lateral sclerosis in other areas of the world, and at 1 time was the Chamorro's leading cause of death (Arnold et al 1953; Kurland and Mulder 1954; Reed and Brody1975; Lilienfield et al 1994). The high prevalence of ALS-PDC facilitated the study of neurodegenerative diseases throughout the world. Hirano and colleagues first defined ALS-PDC of Guam (Hirano et al 1961a), and the identification of the Hirano body in this population has contributed to recognition and investigation of classic amyotrophic lateral sclerosis, Alzheimer disease, and Parkinson disease (Hirano et al 1961b). However, no clearly defined etiologic agent has been identified, and because of a decline in reported new cases of ALS-PDC, the Guam research outpost was closed in 1985 (Garruto et al 1985; Lavine et al 1991).

The content you are trying to view is available only to logged in, current MedLink Neurology subscribers.

If you are a subscriber, please log in.

If you are a former subscriber or have registered before, please log in first and then click select a Service Plan or contact Subscriber Services. Site license users, click the Site License Acces link on the Homepage at an authorized computer.

If you have never registered before, click Learn More about MedLink Neurology  or view available Service Plans.