Lytico-Bodig

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Lytico-Bodig , also known as Lytigo-Bodig , is the name of a disease in the Chamorro language .

Lytico-Bodig is an "amyotrophic lateral sclerotic Parkinson's disease" (ALS-PDC) and was named in 1961 by the neuroscientist Asao Hirano . It is a neurodegenerative disease of unknown etiology that exists on Guam . The disease is similar to amyotrophic lateral sclerosis (ALS), Parkinson's disease, and Alzheimer's disease .

It was first reported in three death certificates on Guam in 1904 . All death certificates noted forms of paralysis . Cases increased among the Chamorro , making the disease the leading cause of adult death between 1945 and 1956. There were around 200 cases per 100,000 inhabitants per year; thus the prevalence was one hundred times higher than among the global population. The neurologist Oliver Sacks presented the disease in detail in his book The Iceland of the Colorblind ago. Subsequently, Sacks and Paul Alan Cox wrote that the Mariana flying fox , which occurs almost exclusively on Guam and is now threatened with extinction due to overhunting, feeds mainly on sago palm ferns and beta-methylamino-L-alanine (BMAA), a neurotoxin, in accumulates fat on his body. The Mariana fruit bat took its place after the Guam fruit bat, often eaten by the Chamorro, became extinct .

Since the Chamorro ate the fruit bats, it was assumed that they also ingested the BMAA, which either triggered the disease or supported its development. Failure to eat fruit bats also reduced the incidence of the disease.

history

Lytico-Bodig was discovered by Zimmermann in 1945 and then by the US Navy and the Public Health Service . The researchers found amyotrophic lateral sclerosis to be 50–100 times more common than in the rest of the world, and a significant increase in Parkinson's disease with dementia . From 1940 it was the leading cause of death among adults of the Chamorros.

Symptoms

Lytico-Bodig shows itself in two ways:

  • Lytico is a progressive paralysis that is similar to ALS .
  • Bodig is similar to Parkinson's with occasional dementia .

Lytico

As with Bodig, the shapes vary from patient to patient. Patients show muscle atrophy , maxillofacial paralysis , the inability to speak or swallow, resulting in suffocation. Some patients retain their full mental abilities until death. The diaphragm and other respiratory muscles can become paralyzed and require external ventilation. Saliva must be sucked out regularly to prevent ingestion. This form of Lytico-Bodig is fatal in all cases.

Soily

There is no known standard form of Bodig, and the cases that have come to light have come in many different variations.

“The doctor visited a patient who had just suddenly come down with a virulent form. His symptoms had begun 18 months before, starting with a strange immobility and a loss of initiative and spontaneity; he found he had to make a huge effort to walk, to stand, and to make the least movement - his body was disobedient. The immobility attacked with frightening speed, and within a year, he was unable to stand alone and could not control his posture. "

“The doctor visited a patient who suddenly became ill with an aggressive form. His symptoms first appeared 18 months ago, starting with reduced mobility, loss of initiative, and spontaneity; he found that it took a lot of effort to run, stand, and make even small movements - his body wouldn't obey him. The immobilization proceeded at great speed; within a year he was no longer able to control his posture. "

- Oliver Sacks : The Island of the Colorblind

Progressive dementia is also one of Bodig's characteristics. In patients with dementia, aphasia , restlessness, irrational behavior such as violence, and flushes are also part of the disease. There are manic episodes with ups and downs. Patients with an aggressive disease also often show drooping mouths and profuse salivation, with a paralyzed tongue that makes it impossible to speak and swallow. Arms and legs are restricted in their mobility and show spasticity . As the disease progresses, catatonia and tremor also become apparent . Except in cases of dementia, most people are able to think clearly.

Possible mechanism

The mechanism behind it is complex and largely not understood. In autopsies neurofibrillary tangles found in the brain that correspond to those of Alzheimer's.

Genetic hypothesis

A genetic origin was initially suspected based on the situation in Guam. The Chamorros who grew up outside of Guam did not develop the disease, and some non-Chamorros who moved to Guam developed the disease. The genetic cause hypothesis was therefore rejected.

Cycad Hypothesis

The starch from the seeds of Cycas micronesica is used in the traditional diet of the Chamorro. The seeds are crushed to make a flour called “fadang”. This flour is cleaned several times because the seeds are poisonous. Since many animal experiments could not prove that the toxicity leads to Lytico-Bodig, the hypothesis was rejected for the first time in 1950. In 1967 the anthropologist Arthur Bell was asked to test cycad seeds as a result of a study of lathyrism in connection with oxalyldiaminopropionic acid . He discovered another toxic substance, "beta-methylamino-L-alanine" (BMAA). The hypothesis was later rejected a second time because the toxicity from BMAA was not high enough. Further analyzes showed that BMAA bound to proteins , as in Fadang, leads to a higher incidence. The theory was later withdrawn by Paul Cox and Oliver Sacks due to new aspects of the diet of the Chamorro. In addition, they found that BMAA is produced by symbiotic cyanobacteria in the roots of cycads. The fruit bats also ate the seeds of the cycads; Due to bioaccumulation in body fat, a few eaten fruit bats were enough to achieve BMAA levels that trigger the symptoms of the disease. Cox also observed a decrease in cases associated with the reduction in fruit bats eaten.

Individual evidence

  1. ↑ Globe L: Progressive supranuclear palsy in the molecular age . In: The Lancet . 356, No. 9233, September 2000, pp. 870-871. doi : 10.1016 / s0140-6736 (00) 02672-6 .
  2. ^ A b c John C. Steele: Parkinsonism - Dementia Complex of Guam . In: Movement Disorders . 20, 2005, pp. 99-107. doi : 10.1002 / mds.20547 .
  3. ^ Katie Moisse: A Batty Hypothesis on the Origins of Neurodegenerative Disease Resurfaces . Scientificamerican.com. September 24, 2013. Retrieved September 28, 2013.
  4. ↑ Brody JA, Chen K: Changing epidemiologic patterns of Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia on Guam . In: Motor neuron diseases research on ALS and related disorders . 1969, pp. 61-79.
  5. ↑ a b c d Walter G. Bradley, Deborah C. Mash: Beyond Guam: The cyanobacteria / BMAA hypothesis of the cause of ALS and other neurodegenerative diseases . In: Amyotrophic Lateral Sclerosis . 10, 2009, pp. 7-20. doi : 10.3109 / 17482960903286009 .
  6. ↑ a b Oliver Sacks: The Island of the Colorblind . Random House, New York 2006, ISBN 0-679-77545-5 .
  7. ↑ a b Cox PA, Banack SA, Murch SJ: Biomagnification of cyanobacterial neurotoxins and neurodegenerative disease among the Chamorro people of Guam . In: PNAS . 100/23, 2003, pp. 13380-13383. doi : 10.1073 / pnas.2235808100 .
  8. ↑ Holt Camp W: The emerging science of BMAA . In: Environmental Health Perspectives . 120/3, 2012, pp. 110-116. doi : 10.1289 / ehp.120-a110 . PMID 22382274 . PMC 3295368 (free full text).
  9. ^ Greg Miller: Guam's Deadly Stalker: On the Loose Worldwide? . In: Science . 313, No. 5786, 2006, pp. 428-431. doi : 10.1126 / science.313.5786.428 . PMID 16873621 .
  10. ^ A b Monson, CS, Banack, SA, Cox, PA: Conservation implications of Chamorro consumption of flying foxes as a possible cause of amyotrophic lateral sclerosis-parkinsonism dementia complex in Guam . In: Conservation Biology . 17, No. 3, 2003, pp. 678-686. doi : 10.1046 / j.1523-1739.2003.02049.x .
  11. ↑ Lt. Cmdr. HM Zimmerman; Medical Officer in Command: Progress Report of Work in the Laboratory of Pathology During May 1945 . In: Letter . June 1, 1945.
  12. ↑ Koerner, DR .: Amyotrophic lateral sclerosis on Guam. A clinical study and review of the literature . In: Ann Intern Med . 37, 1952, pp. 1204-1220. doi : 10.7326 / 0003-4819-37-6-1204 .
  13. ^ Arnold A, Edgren DC, Palladino VS: Amyotrophic lateral sclerosis. Fifty cases observed on Guam . In: J Nerv Ment Dis . 117, 1953, pp. 135-139. doi : 10.1097 / 00005053-195311720-00005 .
  14. ↑ CC Plato, RM Garruto, D. Galasko, U. Craig, M. Plato, A. Gamst, JM Torres, W. Repeatedly: Amyotrophic lateral sclerosis and parkinsonism-dementia complex of Guam: Changing incidence rates during the past 60 years . In: American Journal of Epidemiology . 157, No. 2, 2003, pp. 149-157. doi : 10.1093 / aje / kwf175 . PMID 12522022 .
  15. ^ HR Morris; p. Al-Sarraj; C. Schwab; K. Gwinn-Hardy; J. Perez-Tur; NW Wood; J. Hardy; AJ Lees; PL McGeer; SE Daniel; JC Steele ;: A clinical and pathological study of motor neurone disease on Guam . In: Brain . 124, No. 11, 2001, pp. 2215-2222. doi : 10.1093 / brain / 124.11.2215 .
  16. ↑ Wendee Holtcamp: The Emerging Science of BMAA: Do Cyanobacteria Contribute to Neurodegenerative Disease? . In: Environ Health Perspect . 120, No. 3, March 2012, pp. 110-116. doi : 10.1289 / ehp.120-a110 . PMID 22382274 . PMC 3295368 (free full text).
  17. ↑ Vega A, Bell EA: Alpha-amino-beta-methylaminopropionic acid, a new amino acid from seeds of cycas circinalis . In: Phytochemistry . 16, 1967, pp. 759-762. doi : 10.1016 / s0031-9422 (00) 86018-5 .
  18. ↑ Duncan MW, Steele JC, Kopin LJ, et al: 2-Amino-3- (methylamino) -propanoic acid (BMAA) in cycad flour: an unlikely cause of amyotrophic lateral sclerosis and parkinsonism-dementia of Guam . In: Neurology . 40, 1990, pp. 767-772. doi : 10.1212 / wnl.40.5.767 .
  19. ↑ Kisby GE, Ellison M, Spencer PS: Content of the neurotoxins cycasin (methylazoxymethanol bD-glucoside) and BMAA (bN-methylamino-L-alanine) in cycad flour prepared by Guam Chamorros . In: Neurology . 42, 1992, pp. 1336-1340. doi : 10.1212 / wnl.42.7.1336 .
  20. ↑ Cheng R, Banack SA: Previous studies underestimate BMAA concentrations in cycad flour . In: Amyotrophic lateral sclerosis . 10, 2009, pp. 41-43. doi : 10.3109 / 17482960903273528 .
  21. ↑ SA Banack, SJ Murch, PA Cox: Neurotoxic flying foxes as dietary items for the Chamorro people, Marianas Islands . In: J Ethnopharmacol. . 106, 2006, pp. 97-104. doi : 10.1016 / j.jep.2005.12.032 .
  22. ↑ Banack SA, Cox PA: Biomagnification of cycad neurotoxins in flying foxes . In: Neurology . 61, 2003, pp. 387-389. doi : 10.1212 / 01.wnl.0000078320.18564.9f .
  23. ↑ Cox, PA, Davis, DA, Mash, DC, Metcalf, JS, Banack, SA .: Dietary exposure to an environmental toxin triggers neurofibrillary tangles and amyloid deposits in the brain . In: Proceedings of the Royal Society B . 283, No. 1823, 2015, S. 20152397. doi : 10.1098 / rspb.2015.2397 .