Autonomic neuropathies are peripheral nerve disorders with disproportionate involvement of autonomic fibers.
(See also Overview of the Autonomic Nervous System.)
The best known autonomic neuropathies are those accompanying peripheral neuropathy due to diabetes, amyloidosis, or autoimmune disorders.
Autoimmune autonomic neuropathy is an idiopathic disorder that often develops after a viral infection; onset may be subacute.
Autonomic insufficiency is usually a late manifestation in alcoholic neuropathy.
Other causes can include toxins, drugs, and paraneoplastic syndromes.
Symptoms and Signs of Autonomic Neuropathies
Common symptoms of autonomic neuropathies include orthostatic hypotension, neurogenic bladder, erectile dysfunction, gastroparesis, and intractable constipation.
When somatic fibers are involved, sensory loss in a stocking-and-glove distribution and distal weakness may occur.
Diagnosis of Autonomic Neuropathies
Clinical evaluation
Diagnosis of autonomic neuropathy is based on demonstration of autonomic failure and of a specific cause of neuropathy (eg, diabetes, amyloidosis).
Autoimmune autonomic neuropathy may be suspected after a viral infection.
Tests to detect serum ganglionic nicotinic acetylcholine receptor antibody alpha-3 (anti-ganglionic AChR [α3-AChR ] antibody) may be done. This antibody is present in about half of patients with autoimmune autonomic neuropathy and is occasionally present in patients with other autonomic neuropathies.
Treatment of Autonomic Neuropathies
Treatment of underlying disorders
Sometimes immunotherapy, plasma exchange, or IV gamma-globulin
Underlying disorders are treated, as are symptoms.
Autoimmune autonomic neuropathy may respond to immunotherapy; plasma exchange or IV gamma-globulin can be used for more severe cases.
Key Points
Diagnose based on identifying symptoms due to autonomic failure (eg, orthostatic hypotension, neurogenic bladder, erectile dysfunction, gastroparesis, intractable constipation) and a cause of neuropathy.
Treat underlying disorders if identified; try immunotherapy if autoimmune autonomic insufficiency is diagnosed or, if symptoms are severe, plasma exchange or IV gamma-globulin.
