[Baroreflex sensitivity and chronic pain : Pathogenetic significance and clinical implications]

Area of Science:

• Cardiovascular physiology
• Pain neuroscience
• Autonomic nervous system regulation

Background:

• Cardiovascular dynamics and pain perception are linked in pain regulation.
• Healthy individuals show increased sympathetic arousal and blood pressure with acute pain.
• Arterial baroreceptors relay blood pressure changes to the brainstem (dmNTS), influencing autonomic responses and pain modulation.

Purpose of the Study:

• To review the baroreflex arc's role in chronic pain development and maintenance.
• To discuss the impact of learning mechanisms on pain and baroreflex function.
• To explore mechanism-based treatments for hypertensive stress reactivity in chronic pain.

Main Methods:

• Review of existing literature on baroreflex function, pain perception, and autonomic regulation.
• Analysis of the relationship between blood pressure, pain sensitivity, and baroreflex sensitivity (BRS).
• Discussion of neurobiological pathways involving the dorsomedial nucleus tractus solitarius (dmNTS) and higher cortical areas.

Main Results:

• In healthy subjects, blood pressure and pain sensitivity are inversely related.
• Chronic pain patients, particularly a subgroup, exhibit impaired baroreflex sensitivity and dmNTS activity.
• Reduced baroreflex function is associated with decreased autonomic regulation and pain inhibition.

Conclusions:

• The baroreflex arc is a potential key factor in the development and chronicity of pain.
• Learning mechanisms and cognitive-affective processes significantly modulate baroreflex function and pain.
• Individualized, mechanism-based treatments are needed for patients with impaired baroreflex sensitivity and hypertensive stress reactivity.