Carotid baroreflex testing using the neck collar device.

A neck chamber device for stimulation of carotid sinus baroreceptors by changing carotid transmural pressure was first described in 1957 by Ernsting and Parry and, with several modifications, has been extensively used in a number of physiological and clinical studies. This article outlines the evolution of neck chamber devices and describes some of the advantages and limitations of the technique. We also describe the responses in healthy subjects and the changes observed in patients with some disorders affecting the autonomic nervous system.