Autonomic neuropathies

Purpose of review: To update recent advances in the pathogenesis, pathophysiology and treatment of some autonomic neuropathies. Recent findings: When evaluating a patient with subacute autonomic neuropathy, certain autoantibodies are important in diagnosis and may influence management. Ganglionic antibody may be pathogenetically important while the paraneoplastic antibodies alert the clinician to the presence of an occult neoplasm. Autonomic failure is an integral component of diabetic neuropathy. Sildenafil is safe and efficacious in treating erectile dysfunction in diabetic patients. Sympathetic cardiac hyperinnervation can occur concurrently with denervation in diabetic neuropathy The gene mutations for hereditary sensory and autonomic neuropathies I, III, and IV are now known and there is clear unmyelinated fiber loss. Additional options for treatment of orthostatic hypotension include erythropoietin and, surprisingly, water. Botulinum toxin is efficacious, at least for a time, for the treatment of palmar and axillary hyperhidrosis. Summary: Ganglionic antibody likely mediates autoimmune autonomic neuropathy. Sympathetic cardiac hyperinnervation can occur and could potentially cause arrhythmia and sudden death. Knowledge of gene mutations of hereditary sensory and autonomic neuropathies I, III and IV could lead to more secure diagnosis of the disorders. Effective treatment of essential hyperhidrosis with botulinum toxin injection has been demonstrated. It might be possible to improve treatment of orthostatic hypotension acutely with water imbibation and chronically with erythropoieting.