An epidemic of neuropathy in Cuba during 1992-1993. The etiology is likely nutritional deficiencies, particularly thiamine, compounded by toxic effects of alcohol and tobacco use.
This marked a period of acute food shortage and changes in the Cuban basic diet where studies were done resulting in unconclusive hypothesis, example: the wide introduction of products based on unfermented soy beans affecting vitamins absortion.
References
Cuban neuropathy Wikipedia(Text) CC BY-SA