Parasympathetic rebound following EMG biofeedback training: a case study.

The self-regulation literature contains very few reports of negative side-effects stemming from biofeedback training. Nevertheless, the case reported here is unique in that immediately following each of several early EMG feedback sessions, an otherwise headache-free patient reported an acute attack of headache and nausea. These attacks, the conditions under which they appeared, and the conditions leading to their remission will be described. Discussion will focus on the possible physiological mechanisms involved.