baroreflex failure
Baroreflex failure is a rare disorder that causes fluctuations in blood pressure with episodes of severe hypertension (high blood pressure) and elevated heart rate in response to stress, exercise, and pain. Individuals may also have hypotension (low blood pressure) with normal or reduced heart rate during periods of rest. Symptoms of baroreflex failure may include headache, sweating, and a heart rate that does not respond to medications. The onset of baroreflex failure may be very abrupt or more gradual. In many cases, the cause of baroreflex failure is not known. However, baroreflex failure can result from surgery or radiation treatment for cancers of the neck, injury to the nerves involved in sensing blood pressure, or a degenerative neurologic disease. Treatment usually involves medications to control blood pressure and heart rate along with stress reduction techniques.