Emerging subspecialties in neurology: autonomic disorders.

Autonomic nervous system (ANS) dysfunction as a cause of disease is an increasingly recognized health problem, not only in the field of neurology, but also in cardiology, gastroenterology, endocrinology, urology, psychiatry, and primary care medicine. Patients may present with a myriad of symptoms including orthostatic intolerance, recurrent syncope, labile blood pressure, disorders of sweating and thermoregulation, neurogenic bladder, sexual dysfunction, gastrointestinal dysmotility, pupil abnormalities, and sleep disorders. These symptoms may, in turn, be a consequence of genetic (e.g., hereditary sensory and autonomic neuropathies, transthyretin amyloidosis), neurodegenerative (e.g., Parkinson disease [PD], multiple system atrophy [MSA]), autoimmune (e.g., autoimmune ganglionopathies), or acquired disorders (e.g., spinal cord lesions, type 2 diabetes). Although autonomic symptoms may be among the most debilitating features of these progressive conditions, they are often treatable. Autonomic disorders specialists require a comprehensive knowledge of the anatomy, physiology, and pharmacology of the ANS, understanding of the pathophysiology and management of acute and chronic autonomic conditions, and expertise in the performance and interpretation of clinical and laboratory evaluation of the ANS.