Chinese Restaurant Syndrome
The “Chinese Restaurant Syndrome” manifests as pain and burning sensations about the face, neck and trunk.
Associated with ingestion of large quantities of monosodium glutamate, used in the food as a flavor enhancer.
Glutamate is an essential amino acid.
For this reason it was believed that it might be metabolically useful in the CNS, however, 1950s experiments showed the opposite, it was a toxin at high levels.
By 1969 it was discovered that peripheral administration of glutamate administration resulted in cerebral neuron destruction. It caused vomiting and convulsions.
Dunnett, Stephen, B, Fawcett, James, W, and Rosser, Anne, E. 2001. Brain damage, brain repair. Oxford medical publications, Oxford University Press.