What is Dysautonomia?
Dysautonomia is a general name for one of a group of neurological conditions that affect the autonomic nervous system (ANS). The ANS is responsible for automatic body functions such as heart rate, blood pressure, breathing, body temperature, digestion, and sexual function. Dysautonomias occur when the ANS doesn’t function properly and can affect one or more of the functions controlled by the ANS. It may also be called autonomic dysfunction or autonomic neuropathy.
Symptoms of dysautonomia vary widely from case to case. In some cases, symptoms are confined to one body function or system. In other cases, symptoms affect the entire ANS, a condition called pure autonomic failure.
The symptoms may vary in severity, and they may come and go. In some cases, symptoms may be triggered by external factors such as physical exertion or emotional stress.
Common symptoms of dysautonomia include:
- Abnormal heart rate (too fast or too slow)
- Swings in body temperature
- Problems with blood pressure (too low or too high)
- Problems with sweating (too much or too little)
- Low blood sugar
- Dizziness or balance problems
- Blurred vision
- Shortness of breath
- Chest pain
- Nausea or vomiting
- Sleep disruptions
- Sensitivity to light or noise
- Sexual dysfunction
- Trouble with mental focus or concentration
Types of Dysautonomia
Dysautonomia can be grouped into two broad categories depending on its underlying cause.
- Primary dysautonomia is autonomic dysfunction that develops on its own without the presence of an underlying condition.
- Secondary dysautonomia arises as a result of another disease, disorder, or medical condition.
What Causes Dysautonomia?
Dysautonomia can occur alone with no identifiable underlying cause or may occur due to a disease, medical condition, or triggering event.
Some conditions that may underlie dysautonomia include:
Is Dysautonomia Hereditary?
Most cases of primary dysautonomia don’t seem to be inherited, but some of the conditions that cause secondary dysautonomia, such as Ehlers-Danlos Syndrome, may have a genetic component.
A disease called familial dysautonomia (FD) does run in families and can be inherited. FD is most common in people of Eastern European Jewish descent but is extremely rare in the general population. It is caused by an abnormal change (mutation) in the ELP1 gene, which is responsible for producing a protein found in brain cells. Disrupted production of this protein in people with the mutation may interfere with brain cell function and lead to the symptoms of dysautonomia.
FD is inherited in an autosomal recessive pattern. This means a child must inherit two copies of the gene mutation, one from each parent, to develop the disorder. People with only one copy of the mutated gene usually will not develop FD but will be carriers who can pass the mutation on to their children. Two carrier parents have a 25 percent chance of having a child with FD with each pregnancy. Half of their pregnancies will produce a carrier; a quarter of them will produce a child without the mutated genes.
How Is Dysautonomia Detected?
Because the autonomic nervous system is associated with a wide range of body functions, problems with the ANS can manifest in many different ways depending on where and how the nerves are malfunctioning.
Some potential warning signs of ANS problems include:
- Shortness of breath
- Problems swallowing
- Low blood pressure
- Low heart rate
- Digestive disruptions
- Nausea or vomiting
How Is Dysautonomia Diagnosed?
Doctors may take several different diagnostic steps when suspecting a patient may have autonomic dysfunction. The exact steps will vary depending on your symptoms. Possible diagnostic procedures include:
- Imaging. Magnetic resonance imaging (MRI), ultrasound, or computerized tomography (CT) scans may be used to look for intestinal blockages.
- Endoscopy. This procedure uses a small camera to examine the digestive tract.
- Echocardiogram or electrocardiogram tests measure heart function.
- Exercise stress tests measure heart function during exertion.
- Laboratory tests may be used to test for conditions such as anemia that could cause dizziness or fainting.
- A tilt table test looks for causes of dizziness related to blood pressure or heart rate.
PLEASE CONSULT A PHYSICIAN FOR MORE INFORMATION.
How Is Dysautonomia Treated?
Treatment of secondary dysautonomia usually involves treatment of the underlying disorder. In cases where the underlying cause is treatable, dysautonomia symptoms may improve or resolve with treatment.
Common treatments for dysautonomia itself include:
- Increasing fluid intake
- Increasing salt intake
- Adjusting medications that lower blood pressure
- Medications such as fludrocortisone acetate or midodrine to increase blood pressure
- Sleeping with your head elevated
How Does Dysautonomia Progress?
In many cases, dysautonomia can be managed effectively with lifestyle changes and other treatments. However, the disorder may lead to serious, potentially life-threatening complications if not managed well. Possible complications include:
- Swings in blood sugar levels
- Injuries from falls caused by fainting or dizziness
- Respiratory infections
How Is Dysautonomia Prevented?
There is no known way to prevent dysautonomia.
Dysautonomia Caregiver Tips
Some people with autonomic dysfunction also suffer from other brain and mental health-related issues, a condition called co-morbidity. Here are a few of the disorders commonly associated with dysautonomia:
Dysautonomia Brain Science
Scientists are trying to understand why dysautonomia sometimes occurs in people who have suffered a concussion or other traumatic brain injury. Many people who have suffered a head injury experience dysfunction in both of the two main components of the autonomic nervous system: the parasympathetic system (which, in general, helps automatic functions relax after periods of stress) and the sympathetic system (which triggers “flight or fight” responses in reaction to stress or threats).
Dysautonomia symptoms often associated with head injuries include:
- Fluctuating body temperature
- Irregular heart rate
- Digestive issues (diarrhea, constipation, nausea, vomiting)
- Irregular blood pressure
- Sleep disruption
- Light sensitivity
- Mood swings
- Chest pain
- Muscle tension
- Sexual dysfunction
Researchers have not been able to determine why head injuries may trigger autonomic dysfunction. Prominent theories include:
- Problems in the insula or the anterior cingulate cortex, structures that play a vital role in connecting the autonomic nervous system to the parts of the brain that respond to stimuli
- Problems with the vestibular system, the part of the nervous system crucial for the sense of balance and a person’s perception of their body’s position in space
Title: Blood Pressure Effects on Cognition and Brain Blood Flow in PD
Principal investigator: Katherine Longardner, MD
University of California San Diego
San Diego, CA
Parkinson’s disease (PD) is the second most common neurodegenerative disorder worldwide. Besides causing symptoms that impair movement, PD also causes non-motor symptoms, such as problems thinking and orthostatic hypotension (OH), i.e., low blood pressure (BP) when standing. About one-third of people with PD have OH, which can cause sudden, temporary symptoms while upright, including lightheadedness, dizziness, and fainting. People with PD and OH can also experience problems thinking that occur only while upright and not while sitting – this can happen without other symptoms, such as feeling dizzy or faint. However, the level of low BP that can affect thinking remains unknown, and no guidelines exist for treating OH when it happens without symptoms. This is significant because OH could be a treatable risk factor for thinking problems in PD, but OH is often not treated if people do not report obvious symptoms.
This project’s goal is to determine how BP affects brain function in PD. The proposed experiments will measure BP and brain blood flow continuously in real time using innovative wearable technology. People with PD with OH and without OH will undergo repeated cognitive tests while sitting and while upright. Researchers will study the associations between BP, thinking abilities, and brain blood flow, and will compare groups with and without OH. These findings could be significant because if a certain level of BP correlates with thinking abilities, then treating OH in PD may prevent thinking problems, improve health-related quality of life, and reduce disability and healthcare costs.
Title: The Natural History of Familial Dysautonomia
Principal investigator: Horacio Kaufmann, MD
NYU Langone Medical Center
New York, NY
The study will collect clinical information from patients with FD and allow them to give blood to help develop biological markers of the disease to aid diagnosis and treatment.
This is a non-invasive, non-interventional, observation study that poses minimal risk for participants. The study will document the clinical features of patients with FD over time by storing their routine clinical test results in a central database. The study will involve collaborators at other specialist clinics worldwide who follow/evaluate patients with FD annually. Providing blood for future use is optional.
Specific Aim 1: Define FD’s phenotypic characteristics, severity, and clinical evolution on a patient-by-patient basis. Investigators will enroll patients with FD in a multi-center observational natural history study to evaluate their biochemical, neurological, and autonomic phenotype. Investigators will follow patients to systematically study the onset and scaled severity of all clinical problems. Investigators will define progression rates of patients outside of a clinical trial to distinguish between static and progressive features, a challenge in congenital neuropathies. Investigators will continue banking blood to look for ways to monitor the disease phenotypes. Biomarkers that quantify the disease’s renal, cardiovascular, respiratory, skeletal, and cognitive aspects will be evaluated. This information is relevant when monitoring toxicity to drugs in clinical trials. Detailed clinical follow-up of patients with FD will allow investigators to determine when standard-of-care therapies (e.g., non-invasive ventilation, gastrostomy feedings) should be initiated and how these impact survival outcomes.
Specific Aim 2: Develop ways to measure progressive neurological deficits as outcome measures for future clinical trials. Investigators will test the hypothesis that worsening gait ataxia and progressive visual loss are caused by ongoing neuronal degeneration. Investigators will develop precise outcome measures based on these deficits to test the efficacy of new treatments. Investigators will prospectively evaluate longitudinal changes in the retinal structure (with optical coherence tomography) and visual function in a cohort of patients with FD. Investigators will determine the extent and severity of retinal abnormalities in all patients and how they change over time. Investigators will establish whether structural abnormalities in the retina are correlated with disease severity and look for functional correlates as measured by visual acuity and color discrimination. Following the recent discovery that gait ataxia in patients with FD results from sensory deficits, investigators will perform quantitative assessments of passive joint angle matching at the knee to measure proprioceptive acuity. Investigators will determine how these measures change over time and their impact on daily function and quality of life.
An organized, multi-site natural history study of patients with FD will enable investigators to define disease-specific outcomes for testing new therapies, a significant breakthrough for these patients. The study also offers a unique opportunity to understand better how the brain develops when devoid of crucial sensory inputs.
Title: VNS Prospective Neuromodulation of Autonomic, Immune, and Gastrointestinal Systems (VNSAIG)
Contact: Meena Vessell, MD
University of Louisville
Vagal nerve stimulation is a neurosurgical procedure involving the implantation of an impulse generator battery with leads placed into the vagus nerve in the neck. This procedure was FDA-approved for epilepsy in the 1990s and is commonly performed as an outpatient surgery. The mechanism of efficacy is not well understood; however, it is increasingly recognized that electrical stimulation of the vagus nerve may impact other organ systems in the body, including the immune, gastrointestinal and autonomic systems. The primary objective of this study is to characterize the pre- and post-operative bowel habits and gut microbiome of patients implanted with a vagal nerve stimulator (VNS) for epilepsy. Secondary objectives of this study include: (1) to characterize the pre- and post-operative autonomic profile, (2) to characterize the pre- and post-operative immune profile, and (3) to elucidate whether gut microbiota changes are related to VNS efficacy for epilepsy.