
Nothing unisual.
Quote:
"
Chinese Restaurant Syndrome (CRS):
a transient syndrome, associated with arterial dilatation, due to ingestion
of monosodium glutamate, which is used liberally in seasoning chinese
food; it is characterized by throbbing of the head, lightheadedness,
tightness of the jaw, neck and shoulders, and bachache.
"
End quote.
Source: Dorland's Illustrated Medical Dictionary, 27th edition, 1988, W.B. Saunders, p 1632.

This was known long ago.  Brain produces and uses some MSG naturally,
but not in doses it is served at some chinese places. 
Having said that, i might add, that in MHO, MSG does not enhance
flavor enoughf for me to miss it.  When I go to chinese places,
I order food without MSG.  Goos places will do it for you.
A prerequisite for such a service would be a waiter, capable of
understanding, what you want.


Good Luck.


am