Neurologists have grappled with a cluster of amyotrophic lateral sclerosis cases in France, where a fondness for a toxic wild mushroom may hold the answer

Well known to skiers and alpinistes, Montchavin also has grabbed the attention of medical researchers as the site of a highly unusual cluster of a devastating neurological disease, amyotrophic lateral sclerosis.

A remarkable thing about ALS is the mystery surrounding the underlying cause or causes of most cases. To some extent, the disease runs in families, making up as much as 10 to 15 percent of the toll, and scientists have pinpointed numerous genes that drive these familial cases. Beyond those, medical researchers have variously found that exposure to cigarette smoke, air pollution and some industrial chemicals is associated with an increased risk of ALS. And US military veterans also have a 50 percent higher risk of ALS than nonveterans. Still, no definitive cause and effect has been established.

An island of suspect seeds

The notion that something in food might cause ALS does not come out of the blue. It comes from Guam, where US medical researchers, near the end of World War II, documented an epidemic of neurological disease among the island’s native Chamorro people that has by now largely disappeared. At its peak, the epidemic was so severe, with a prevalence more than 100 times the norm, and so complex, incorporating a second neurological disorder known as parkinsonism-dementia, that the National Institutes of Health opened a research station on the island to study the disease, known as Western Pacific ALS-PDC.