Vagus nerve pain referred to the craniofacial region. A case report and literature review with implications for referred cardiac pain.

The pain of angina pectoris and myocardial infarction is sometimes referred to the head and neck region. The mechanism for this effect remains obscure. A case is presented here that reports that electrical stimulation of a cardiac branch of the left vagus nerve in humans can cause referred craniofacial pain. This leads to the hypothesis that the vagus nerve plays a role in mediating this pain. A review of the clinical and physiologic literature supports this hypothesis.