Small Fiber and Autonomic Neurology Program

Overview

The autonomic nervous system (ANS) is responsible for the automatic processes not typically under conscious control, such as digestion, sweating, and certain reflexes. The ANS maintains homeostasis, and monitors and controls the body’s internal, visceral environment.

The ANS is essential to life and responds to the body’s needs. For example, if you are dehydrated, your ANS will constrict your blood vessels, tell your heart to beat faster, maintain blood pressure, and redirect your blood to where it’s needed to go. If you start to exercise, the ANS will tell the heart to pump faster and harder, and redirect blood flow to muscles. If you are hot, the ANS is responsible for sweating and redirecting blood flow to the skin to cool the body back down. In addition to controlling these reflexes, the ANS drives behaviors, and is the part of the nervous system that helps make you thirsty and seek water and shade on a hot day.

Most of the time, autonomic symptoms and signs are not diseases. For example, if you develop tachycardia (when your heart beats faster than normal) or fever from infection, the ANS is doing what it’s supposed to do. There are many other examples of autonomic symptoms that are appropriate – not pathologic.

Sometimes, however, these processes go wrong. When neural control of homeostatic processes malfunction, this is called an autonomic disorder, or a "dysautonomia." Dysautonomia is not a diagnosis: it is just a general term describing malfunction of the ANS.

Symptoms of Autonomic Disorders

Patients with autonomic disorders can have symptoms such as lightheadedness with standing, passing out (syncope), constipation, urinary dysfunction, excessively dry mouth, or difficulty tolerating the heat, to name a few. Autonomic disorders cross every field of medicine – patients with autonomic disorders often see urologists, cardiologists, psychiatrists, endocrinologists, gastroenterologists, and many different kinds of physicians. The ANS is often poorly taught in medical training, and many physicians do not feel comfortable or knowledgeable about the ANS or its disorders. It is not unusual for patients to wait months or years before seeing an autonomic specialist. Many autonomic disorders are poorly understood. There is a desperate need for high-quality research and more research support to advance our understanding of the ANS and its disorders.

Autonomic Neurologists

Autonomic neurologists are subspecialists devoted to the diagnosis and treatment of disorders of the ANS. Autonomic specialists focus on certain autonomic diseases that primarily affect the ANS:

• Autonomic neuropathies and autonomic failure syndromes due to diabetes, Parkinson’s disease, multiple system atrophy, or other rarer conditions
• Postural tachycardia syndrome (POTS)
• Small fiber peripheral neuropathies, including diabetic neuropathy
• Genetic disorders with autonomic involvement
• Non-cardiac syncope and presyncope (e.g. vasovagal, neurally-mediated, orthostatic)
• Immune or toxic autonomic neuropathies
• Cerebral blood flow autoregulatory abnormalities
• Central hypothalamic autonomic disorders
• Other less common conditions such as acquired anhidrosis, hyperhidrosis with nerve hyperexcitability, Harlequin syndrome, autoimmune autonomic ganglionopathy, etc.
• Poorly characterized disorders, including hyper-sympathetic disorders

Many other conditions can be affected by the autonomic nervous system, such as constipation, asthma, chronic urticaria (hives) or other allergic conditions, chronic fatigue, and forms of exercise intolerance. Though some of these involve the ANS, autonomic neurologists may not specialize in these disorders, and sometimes other specialists are better positioned to deliver the best care.

Our Services

At the Mass General Brigham Small Fiber and Autonomic Neurology Program, we offer comprehensive evaluations, second opinion consultations, autonomic testing and ongoing expert management for patients with suspected or confirms autonomic disorders. Among the services we offer are:

• Quantitative autonomic screening tests such as deep breathing, Valsalva maneuver, tilt test and sweat tests.
• Skin biopsies for quantification of small nerve fibers, and to look for possible causes.
• Comprehensive testing to look for common and rare causes of autonomic and small fiber disorders.
• Telehealth services.

Treatment plans are tailored to each patient’s diagnosis. 

In addition to evaluation and management services, we offer comprehensive autonomic reflex testing, often referred to as “Autonomic Function Testing” (AFTs). These tests may help your doctor determine whether the autonomic nervous system is functioning as it should.

Learn more about autonomic function testing

Our Team

At the Mass General Brigham Small Fiber and Autonomic Neurology Program, our physicians offer comprehensive evaluations, second opinion consultations, and ongoing expert management for patients with suspected or confirmed autonomic disorders.

Our expert team of physicians, advanced practice providers, nurses, autonomic technicians, trainees, and support staff are dedicated to the care of patients with disorders of the autonomic nervous system (ANS) and somatic small nerve fibers. Neurology residents, neuromuscular fellows, and other fellows and trainees often rotate through our outpatient clinic to learn how to deliver world-class care.

Neurology at Mass General Brigham comprises a diverse yet integrated array of specialized clinical services, including evaluation and management of both inpatients and outpatients, second opinions for complex cases, diagnostic testing and care for the most critically ill.

This collaborative approach enables our team to provide patients with the care they need in a comprehensive and patient focused approach, providing a greater measure of safety, convenience and satisfaction.

Our mission is to provide the best neurological care to patients and their families, create new methods for evaluation and management of neurological diseases and train the next generation of practitioners and academic neurologists.

• Nate Robbins, MD is the Director of the Small Fiber and Autonomic Neurology Program at MGB and the Director of the MGH Neurodiagnostic Autonomic Laboratory. He has oversight over all clinical, research, and educational activities related to small fiber and autonomic neurology throughout the MGB system. He is a board-certified neurologist and has added certification in Autonomic Disorders from the United Council for Neurologic Subspecialties (UCNS).
• Peter Novak, MD, PhD is the founding director of the Autonomic Laboratory at Brigham and Women’s Faulkner Hospital. He is a board-certified neurologist and has added certification in Autonomic Disorders from the United Council for Neurologic Subspecialties (UCNS).
• Khosro Farhad, MD directs the Center for Peripheral Neurology and Autonomic Disorders at Wentworth-Douglass Hospital and Coastal Neurology Services. He is a board-certified neurologist and has added certification in Autonomic Disorders from the UCNS.
• Anne Louise-Oaklander MD, PhD
• Priyanka Shekhawat, MD
• Aditi Varma Doyle, MD
• Erika Wiliams MD, PhD 
• Sarbesh Chalise, FNP
• Josie Pagliuca, FNP
• Victor Luu, PA-C
• Sadie Marciano, PA-C

Associated Faculty and Staff

• David Dredge, MD
• Joshua Okonkwo MD, PhD
• Reza Seyedsadjadi, MD
• Anastasia Vishnevetsy, MD, MPH
• Margaret Naclerio, PA-C
• MGB Neuromuscular Fellows

Nurses

• Virginia Clark, RN
• Kevin Wallace, RN

Contact Us

Mass General Brigham autonomic testing laboratories are found at the following locations.

Massachusetts General Hospital
Phone: 617-726-3644 | Fax: 617-726-2958

Boston Location:
The Neuromuscular Diagnostic Center
165 Cambridge Street, 8th floor (Suite 820)
Boston, MA 02114

Waltham Location:
Mass General Brigham Healthcare Center (Waltham), Specialties
52 Second Avenue
Suite 300
Waltham, MA 02451

Brigham and Women’s Faulkner Hospital
Phone: 617-983-7160 | Fax: 617-983-7195

1153 Centre Street, Suite 4970
Jamaica Plain, MA 02130

Wentworth-Douglass Hospital
Phone: 603-749-0913 (Option 5, then Option 3 to get directly to our office) | Fax: 603-749-0973

Coastal Neurology Services
10 Members Way
Dover, NH 03820

Wentworth-Douglass Hospital Outpatient Center
121 Corporate Drive (Building C)
Portsmouth, NH 03801