Carotid artery palpation
The carotid artery is the main artery supplying blood to the brain. The carotid sinus (CS) is a pressure sensitive receptor located on this artery, which plays a central role in blood pressure homeostasis. Changes in stretch and pressure within the artery are detected by these receptors and transmitted to the brain.
Carotid artery palpation can be done as part of routine pulse examination or in the diagnosis of aortic stenosis. It requires the artery to be palpated by the person conducting the test. In certain individuals who are hypersensitive to such a palpation may develop an exaggerated response, often resulting in dizziness, loss of consciousness and hypotension, numbness or tingling, thereby mimicking the symptoms of stroke.
Carotid artery palpation can also discharge a pre-existing thrombus in the carotid artery, causing an embolus, resulting in stroke.
Such hyper-responsiveness can be spontaneous or induced. Spontaneous responses are rare, while induced responses due to carotid sinus massage occur more frequently. It is found in 0.5-9% of patients with recurrent syncope. Rates of total mortality, sudden death, myocardial infarction or stroke are unaffected.