The Lytico-bodig disease, also known as lateral sclerosis-parkinsonism-dementia, is a neurodegenerative disease of unknown origin that occurs exclusively in the Chamorro people of the island of Guam that has characteristics of both amyotrophic lateral sclerosis (ALS) and parkinsonism.
It is characterized by muscle atrophy, maxillofacial paralysis, inability to speak or swallow, and dementia.
The disease is fatal in all cases, with the diaphragm and respiratory accessory muscles becoming paralyzed in the later stages of the disease.

Observation of the diets of the native Chamorro people led to the creation of the so-called "Cycad hypothesis."
Starches prepared from the seeds of a native cycad species, Cycas micronesica, are used to create the sago-like flour fadang, which forms a major part of the diet of the Chamorro people.
As the seeds contain the highest amount of the toxin found in the plant, it was proposed that a dietary explanation relating to the consumption of poorly processed fadang was poisoning the natives.
After failing to reproduce the symptoms of the disease in animal models, the hypothesis was rejected.
Though the initial cycad hypothesis was rejected, a revised form of the hypothesis was proposed by Paul Alan Cox and Oliver Sacks after observing other elements of the Chamorro diet, specifically flying foxes.
The bats accumulate BMAA in their fat by consuming cycad seeds, resulting a in a high concentration of the neurotoxin.
The Lytico-bodig disease, also known as lateral sclerosis-parkinsonism-dementia, is a neurodegenerative disease of unknown origin that occurs exclusively in the Chamorro people of the island of Guam that has characteristics of both amyotrophic lateral sclerosis (ALS) and parkinsonism. It is characterized by muscle atrophy, maxillofacial paralysis, inability to speak or swallow, and dementia. The disease is fatal in all cases, with the diaphragm and respiratory accessory muscles becoming paralyzed in the later stages of the disease.
Observation of the diets of the native Chamorro people led to the creation of the so-called "Cycad hypothesis." Starches prepared from the seeds of a native cycad species, Cycas micronesica, are used to create the sago-like flour fadang, which forms a major part of the diet of the Chamorro people. As the seeds contain the highest amount of the toxin found in the plant, it was proposed that a dietary explanation relating to the consumption of poorly processed fadang was poisoning the natives. After failing to reproduce the symptoms of the disease in animal models, the hypothesis was rejected. Though the initial cycad hypothesis was rejected, a revised form of the hypothesis was proposed by Paul Alan Cox and Oliver Sacks after observing other elements of the Chamorro diet, specifically flying foxes. The bats accumulate BMAA in their fat by consuming cycad seeds, resulting a in a high concentration of the neurotoxin.
Cycasin