Description

• Any neuropathic process that has predominant effects on the autonomic nervous system
• Process targets small unmyelinated or lightly myelinated peripheral nerves.
• Most of the time, it is caused by diabetes mellitus, which plays a key role in the morbidity and mortality of type 1 and type 2 diabetics.

Epidemiology

Incidence

• Approximately 7% of diabetics have signs of autonomic neuropathy at the time of diagnosis of diabetes.
• Approximately 2% of type 2 and 6% of type 1 diabetics develop autonomic neuropathy each year.

Prevalence

• The prevalence of diabetic autonomic neuropathy is estimated at 20% of diabetics.
• Affects slightly >5 million people in the United States
• The prevalence of all other causes of autonomic neuropathy is significantly lower.

Etiology and Pathophysiology

Autonomic neuropathy can be secondary to diabetes, hypothyroidism, amyloidosis, Guillain-Barré syndrome and other primary neuropathic processes, Parkinson disease, paraneoplastic syndromes, infectious diseases, collagen vascular diseases, nutritional deficiency, and toxic exposures (1).

Genetics
Specific genetic syndromes associated with autonomic neuropathies often present in infancy with failure to thrive

Risk Factors

Autonomic effects of diabetes are most common with long-standing and poorly controlled diabetes.

General Prevention

Exercise improves cardiac autonomic function in diabetic autonomic neuropathy and improves overall autonomic function in prediabetic patients.

Commonly Associated Conditions

• Because the autonomic neuropathy does not occur in isolation, signs of sensory neuropathy are common.
• Sensory neuropathies have autonomic effects that are often subclinical.