Dysautonomias: Clinical Disorders of the Autonomic Nervous System

5 November 2002 | Volume 137 Issue 9 | Pages 753-763

The term dysautonomia refers to a change in autonomic nervous system function that adversely affects health. The changes range from transient, occasional episodes of neurally mediated hypotension to progressive neurodegenerative diseases; from disorders in which altered autonomic function plays a primary pathophysiologic role to disorders in which it worsens an independent pathologic state; and from mechanistically straightforward to mysterious and controversial entities. In chronic autonomic failure (pure autonomic failure, multiple system atrophy, or autonomic failure in Parkinson disease), orthostatic hypotension reflects sympathetic neurocirculatory failure from sympathetic denervation or deranged reflexive regulation of sympathetic outflows. Chronic orthostatic intolerance associated with postural tachycardia can arise from cardiac sympathetic activation after "patchy" autonomic impairment or blood volume depletion or, as highlighted in this discussion, from a primary abnormality that augments delivery of the sympathetic neurotransmitter norepinephrine to its receptors in the heart. Increased sympathetic nerve traffic to the heart and kidneys seems to occur as essential hypertension develops. Acute panic can evoke coronary spasm that is associated with sympathoneural and adrenomedullary excitation. In congestive heart failure, compensatory cardiac sympathetic activation may chronically worsen myocardial function, which rationalizes treatment with ß-adrenoceptor blockers. A high frequency of positive results on tilt-table testing has confirmed an association between the chronic fatigue syndrome and orthostatic intolerance; however, treatment with the salt-retaining steroid fludrocortisone, which is usually beneficial in primary chronic autonomic failure, does not seem to be beneficial in the chronic fatigue syndrome. Dysautonomias are an important subject in clinical neurocardiology.

Author and Article Information

From National Institute of Neurological Disorders and Stroke, Bethesda, Maryland; Vanderbilt University School of Medicine, Nashville, Tennessee; Baker Medical Research Institute, Prahran, Victoria, Australia; and National Center for Complementary and Alternative Medicine, National Institutes of Health, Bethesda, Maryland.

Acknowledgments: The authors thank Courtney Holmes, CMT, and Sandra Brentzel, RN, Clinical Neurocardiology Section, National Institute of Neurological Diseases and Stroke, Bethesda, Maryland; Dr. Simon Bruce, formerly of the National Institute of Child Health and Development, Bethesda, Maryland; Dr. Jacques Lenders, University of Nijmegen, the Netherlands; Drs. Italo Biaggioni, Nancy Flattern, John Shannon, and Randy Blakely, Vanderbilt University School of Medicine, Nashville, Tennessee; Dr. Jens Jordan, Berlin, Germany; Dr. Giris Jacob, Haifa, Israel; and Drs. Hugh Calkins and Peter Rowe, Johns Hopkins School of Medicine, Baltimore, Maryland. They also thank the nursing, technical, and support staff of the Vanderbilt Autonomic Dysfunction Center and of the National Institute of Allergy and Infectious Diseases, National Heart, Lung, and Blood Institute, National Institutes of Neurological Diseases and Stroke and the staff of the National Institutes of Health Positron Emission Tomography Department.

Requests for Single Reprints: David S. Goldstein, MD, PhD, Clinical Neurocardiology Section, National Institutes of Neurological Diseases and Stroke, National Institutes of Health, Building 10 Room 6N252, 10 Center Drive MSC-1620, Bethesda, MD 20892-1620.

An edited summary of a Clinical Staff Conference held on 31 May 2000 at the National Institutes of Health, Bethesda, Maryland.

Authors who wish to cite a section of the conference and specifically indicate its author may use this example for the form of the reference:

Robertson D. Autonomic function in chronic orthostatic intolerance. In: Goldstein DS, moderator. Dysautonomias: clinical disorders of the autonomic nervous system. Ann Intern Med. 2002; 137:756-7.

Current Author Addresses: Drs. Goldstein and Eisenhofer: Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 10, Room 6N252, 10 Center Drive MSC-1620, Bethesda, MD 20892-1620.

Dr. David Robertson: Director, Center for Space Physiology and Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-2195.

Dr. Murray Esler: Baker Medical Research Institute, Commercial Road, 3181 Prahran, Victoria, Australia.

Dr. Stephen Straus: National Center for Complementary and Alternative Medicine, NIH, Building 31 Room 5B37, 31 Center Drive, MSC-2182, Bethesda, MD 20892-2182.