Chinese restaurant syndrome: A syndrome first described in 1968 in people who had eaten Chinese food on which MSG (monosodium glutamate) had been lavished. The syndrome only seems to occur in some people. Their symptoms may include headache, throbbing of the head, dizziness, lightheadedness, a feeling of facial pressure, tightness of the jaw, burning or tingling sensations over parts of the body, chest pain, and back pain. Large amounts of MSG may cause arterial dilatation (widening of arteries). Many Chinese do not believe in the existence of the Chinese restaurant syndrome. It may be a hypersensitive (allergic) reaction.