Lytico-Bodig Disease

Lytico-bodig disease, sometimes spelled Lytigo-Bodig is a neurological disease of uncertain etiology that exists in the United States territory of Guam.

The disease resembles amyotrophic lateral sclerosis (ALS) (more commonly known in North America as Lou Gehrig's disease), Parkinson's disease, and Alzheimer's. First reports of the disease surfaced in three death certificates on Guam in 1904. These death certificates made some mention of paralysis. The frequency of cases grew amongst the Chamorro people on Guam until it was the leading cause of death between 1940 and 1956. The symptoms range from strongly resembling ALS to those resembling Parkinson's dementia complex (PDC). The symptoms tend to show themselves between the ages of 25 and 40. Many victims are not able to speak of their own accord, but they can speak coherently and fluidly when spoken to. The disease is caused by toxins in the cycad trees prevalent on Guam.

Neurologist Oliver Sacks detailed this mysterious condition in his book The Island of the Colorblind . Sacks wrote that a local species of fruit bat, which is now largely extinct due to overhunting, had been feeding on cycads and concentrating β-methylamino--alanine (BMAA), a known neurotoxin, in its body fat. The theory is that consumption of the fruit bat transferred sufficient quantities of the toxin to lead to long-term toxicity, although this has not yet been proven.