Autonomic dysfunction: Diagnosis and management

Area of Science:

• Neuroscience
• Cardiovascular Physiology
• Autonomic Nervous System Research

Background:

• The autonomic nervous system (ANS) is crucial for maintaining physiological homeostasis.
• Widespread ANS connections render it susceptible to disruption by primary (e.g., Parkinson's disease) and secondary (e.g., diabetes mellitus) etiologies.
• Autonomic dysfunction (AUD) leads to diverse symptoms affecting cardiovascular, gastrointestinal, and urogenital systems.

Purpose of the Study:

• To review the causes, pathophysiology, and cardiovascular manifestations of autonomic dysfunction (AUD).
• To emphasize the diagnosis and treatment of orthostatic hypotension (OH) in patients with suspected AUD.
• To highlight diagnostic tools for assessing baroreflex impairment and cardiac sympathetic denervation.

Main Methods:

• Review of existing literature on autonomic nervous system function and dysfunction.
• Analysis of diagnostic approaches including heart rate and plasma norepinephrine response to orthostatic stress.
• Discussion of imaging techniques such as MIBG scintigraphy and 18F-DA PET scanning for cardiac sympathetic denervation.

Main Results:

• Impairment of the baroreflex, due to peripheral and/or cardiac denervation, significantly impacts hemodynamic outcomes during orthostatic stress.
• Heart rate and plasma norepinephrine responses are valuable for diagnosing baroreflex impairment in orthostatic hypotension (OH) and suspected AUD.
• Cardiac sympathetic denervation assessment aids in differentiating preganglionic from postganglionic involvement and diagnosing early neurodegenerative diseases.

Conclusions:

• Autonomic dysfunction arises from various systemic diseases, causing significant cardiovascular and other systemic symptoms.
• Accurate diagnosis of AUD, particularly orthostatic hypotension, relies on assessing baroreflex function and sympathetic denervation.
• Effective management strategies for OH and related cardiovascular manifestations are essential for patients with autonomic dysfunction.