Ten years of investigation have solved the mystery of dozens of cases of amyotrophic lateral sclerosis in the village of Montchavin, in Savoie, and found the culprit: false morels, a toxic species of mushroom.
- There were 14 cases of Charcot between 1991 and 2013 in Montchavin, a Savoyard village.
- Charcot’s disease is a condition that causes progressive paralysis that can go as far as respiratory failure.
- After investigation, the 14 patients had indeed eaten the mushroom on several occasions years before.
This is the end of a medical enigma that has been going on for more than ten years. In the village of Montchavin, not far from La Plagne in Savoie, a larger than average number of inhabitants are affected by Charcot’s disease, a rare neurodegenerative disease. Also called amyotrophic lateral sclerosis (ALS), this condition causes progressive paralysis that can lead to respiratory failure. These cases have long been unexplained but a Franco-American team has just found the cause: the consumption of a toxic mushroom, the false morel.
An abnormally high incidence
In 2009, a local doctor realized that she had just been diagnosed with Charcot’s disease for the third time in a short time. Surprised, she alerted specialists who launched an epidemiological investigation. This revealed the existence of 11 other cases in the village between 1991 and 2013 with unrelated patients, ruling out the possibility of a genetic cause. This is a very high figure, much higher than the national average where the incidence of Charcot’s disease is normally 2 new cases per year per 100,000. Half of the patients have since died.
The first tracks of the investigation were oriented towards an environmental cause. The investigators sifted through everything: traces of bacterial or lead toxins in the water, radon gas in homes, air or soil pollution by pesticides or heavy metals… But none of these factors did not yield conclusive results. It was then that the case took an international turn. Peter Spencer, an American toxicologist from the University of Oregon, heard about the story while working on a similar investigation on the western Pacific island of Guam. There, he had finally found the culprit. This is a local plant, the Japanese cycad.
Mystery solved
The American scientist therefore suggested to the French the possibility of a food trail, of a toxic product consumed by the inhabitants which could have caused the disease. Together, the researchers will suspect the false morel, a widespread mushroom which contains toxins close to those of the cycad by their mode of action. After investigation, it turns out that the 14 patients had indeed consumed the mushroom several times years before, unlike the other villagers. Some have even reported having had somewhat complicated post-meal situations after ingesting dishes based on this mushroom.
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