Arrival of new diseases on Guam: lines of evidence suggesting the post-Spanish origins of Amyotrophic lateral sclerosis and Parkinson's dementia

This paper summarises the follows of a 1992 ethnomedical inquiry looking into the historical origins of Amyotrophic lateral sclerosis and Parkinsonism-dementia (ALS-PDC) composed of several elements on Guam.(1) The Chamorros of Guam and the Commonwealth of the Northern Mariana Islands are individual of three groups known to be affected by means of ALS-PDC. Hypotheses on the causes of these diseases include genetic susceptibility, environmental risk factors or a combination of the sum of two units The study combined reviews of historical and novel medical literature; archaeological data; oral and written interviews; and the unravelling and utilisation of a Risk Factor Questionnaire, designed specifically to obtain information upon the various hypotheses from patients and rules Thus far, ethnohistorical evidence (dating to 1898) available upon Guam points to origins of the two diseases during the Spanish colonial era. based upon a synthesis of available data, we at hand lines of evidence which glance at that ALS-PDC on Guam occurr as a spring of behavioural, both physical and cultural, changes resulting during Spanish colonisation.

Amyotrophic lateral sclerosis and Parkinsonism-dementia composite are progressive and fatal diseases of the central nervous combination of parts to form a whole (CNS) which have been endemic in three foci in the Western Pacific.(2) The predominant areas/groups affected are Chamorros of Guam and the Commonwealth of the Northern Mariana Islands; Japanese in sum of two units villages on the Kii peninsula of Honshu Island; and the Auyu and Jakai races of southeastern Irian Jaya.(3)

Since clarification of the cause(s) of ALS-PDC would help in the identification of the cause(s) of Amyotrophic lateral sclerosis, Parkinson's disease (PD) and Alzheimer's disease (AD), which together affect millions of race throughout the world, these foci have been make subordinate to extensive clinical, pathological, and epidemiological studies above the past 40 years. In greatest in quantity countries, ALS or motor neuron disease, PD and AD offer as distinct diseases, restricted to degeneration of specific areas similar as the brain stem and spinal cord in ALS, in the substantia nigra (a to [i]or[/i] at a great depth pigmented area of the midbrain) in PD and in areas in and below the cerebral cortex in AD. Furthermore, in the individual forms of the three diseases as set in most countries, the first brunt is infrequent before age 40 on the contrary shows an increasing incidence rate with increasing age. Also, in all three diseases there is a familial and presumably genetic form which accounts for 5-15% of the cases. on the other hand in ALS-PDC in the three foci, motor neuron disease, Parkinsonism, and dementia may appear alone or in any combination and the disease is distinguished through the finding of neurofibrillary tangles, diffusely over the CNS. These neurofibrillary tangles, a distinct form of neuronal degeneration, are the hallmark of ALS-PDC as it be met withs in these three foci.

Early epidemiologic studies put in mind ofed the possibility of a genetic cause on the other hand subsequent familial aggregation analyses failed to reveal findings characteristic of any simple Mendelian inheritance proces The search for a susceptibility gene(s) or a mitochondrial gene lack continues, but the recent emphasis has shifted to environmental factors, the principal candidates for which are a deficiency of calcium; and exposing to toxins of the cycad plant which be subservient tos as both a famine pabulum and as a medicine for skin lesions and systemic symptoms.

There is no evidence of a deficiency of calcium intake upon Guam, largely a coral island. Also, a novel study of Chamorros with ALS-PDC at the Clinical Research Center Mayo Clinic, place no signs of abnormal serum calcium. Thus, a possible genetic predisposition, or cycad or other toxins, or a combination of them appears the most likely explanation for the disease.(4) This paper not absents a synthesis of archaeological, written and oral data from Guam. These hint a post-Spanish origin of the unique endemic CN disease ALS-PDC, to date fix only among residents or emigrants of the three known foci in the Western Pacific.

The local Chamorro name for ALS is lytico or lytiku (short for paralytico in that language). This give in charges to the skeletal muscle wasting that issues from degeneration of the motor neuron in the brain stipe and spinal cord. The local confine for PDC is bodig or rayput, which consigns to slowness of movement and difficulty with cognition and memory. Ethnohistorical research has traced ALS upon Guam back to 1815 end death certificates and church records. However, it is uncertain if PDC occurr then as now with ALS and whether the different combinations of clinical features also advance back nearly 200 years in the indigenous populations. PDC is known to have occurr in conjunction with ALS for at least 50 years and is likely to have evolveed as a clinical variant, although it may have initially gone unrecognised as a disease because in like manner many of its symptoms are similar to those of the normal aging process

R M Garruto and Y Yanagihara examined the pattern of ALS-PDC upon Guam and noted that it underwent a dramatic change after World War II.(5) In take a view ofs conducted in the 1950s, ALS was lay the foundation of to be 50 to 100 times more prevalent upon Guam than in the US and other Western countries and similar frequencies of ALS were subsequently lay the foundation of in the other two foci. The ALS in the 1950 and 1960 had a median age of first brunt of about 44 years, whereas the attack of ALS in the population of Rochester, Minnesota, centr around about 65 years. Similarly, the average age of storming of PDC, which had been first described clinically and pathologically alone in the late 1950s, had an average age of assault of about 55 years upon Guam, whereas the median age in Rochester was 70 years for PD and 80 years for AD.(6) After 1960 the incidence rate of the unsullied form of ALS began to present to view a dramatic decline with an increase in age of first brunt whereas the rate for PDC continued with true little change in frequency on the other hand also with an increase in age of onset(7)