Abstract
Head and neck tumors can affect afferent baroreceptor neurons and either interrupt
or intermittently increase their signaling, causing blood pressure to become erratic.
When the afferent fibers of the baroreflex are injured by surgery or radiotherapy
or fail to develop as in familial dysautonomia, their sensory information is no longer
present to regulate arterial blood pressure, resulting in afferent baroreflex failure.
When the baroreflex afferents are abnormally activated, such as by paragangliomas
in the neck, presumably by direct compression, they trigger acute hypotension and
bradycardia and frequently syncope, by a mechanism similar to the carotid sinus syndrome.
We describe our observations in a large series of 23 patients with afferent baroreflex
dysfunction and the cardiovascular autonomic features that arise when the sensory
baroreceptor neurons are injured or compressed. The management of afferent baroreceptor
dysfunction is limited, but pharmacological strategies can mitigate blood pressure
swings, improve symptoms, and may reduce hypertensive organ damage. Although rare,
the prevalence of afferent baroreflex dysfunction appears to be increasing in middle-aged
men due to human papillomavirus related oropharyngeal cancer.
Keywords
afferent baroreflex - baroreflex failure - blood pressure - paraganglioma - neck cancer
