Forms of Dysautonomia

It’s important to note that patients can have more than one form of dysautonomia and symptoms of each form can overlap. If you think you may have a form of dysautonomia, please speak with your healthcare provider. As always, this content is meant as educational information and should be discussed further with your provider.

Postural Orthostatic Tachycardia Syndrome (POTS)

Postural Orthostatic Tachycardia Syndrome (POTS) is one of the more common forms of dysautonomia. The key features of POTS are a sustained increased heart rate upon standing and orthostatic intolerance symptoms. However, people with POTS also experience symptoms regardless of position.

  •  A sustained increase in heart rate of at least 30 beats per minute (bpm) in adults and 40 bpm in individuals aged 12-19 within 10 minutes of standing.  
  • No orthostatic hypotension (no drop in blood pressure of more than 20/10 mm Hg). 
  • Symptoms of orthostatic intolerance (lightheadedness, palpitation, tremors, chest discomfort) have been present for at least 3 months. 
  • Other conditions that cause increased heart rate have been ruled out  (i.e. panic attacks, pain, exercise, caffeine, alcohol, medications, anemia, inappropriate sinus tachycardia, hyperthyroidism, and dehydration).

Current guidelines state that, generally, one person can not have orthostatic hypotension and POTS ⁵.

Finally, people with POTS can pass out, but this is not a key symptom. In fact, only about 30% of those with POTS experience syncope .

Symptoms may include :

  • Orthostatic tachycardia (increased heart rate when standing)
  • Orthostatic intolerance (dizziness, lightheadedness, weakness, shortness of breath, chest tightness, chest pain, heart palpitations, and/or tremors)
  • Fatigue
  • Autonomic symptoms (ex: blood pooling, gastrointestinal symptoms, increased or decreased sweating) 
  • Headaches
  • Cognitive dysfunction (brain fog) 
  • Pain
  • Sleep disturbance 
  • Exercise intolerance 

It is estimated that between 500,000 - 3 million Americans have POTS ¹⁰ ¹¹.

More than 75% with POTS are female ¹² ¹³, and the average age of onset is between 15 and 25 years of age ¹⁴.

Not everyone is able to identify a cause, trigger, or precipitating event for their POTS. However, for some people, symptom onset has occurred after viral illnesses/infection, a surgical procedure, concussion, or during or after pregnancy ¹⁵ ¹⁶ ¹⁷

Researchers have found that POTS commonly occurs with other conditions such as chronic fatigue syndrome, small fiber neuropathy, mast cell activation disorder, hypermobile Ehlers-Danlos syndrome, migraines, gastrointestinal dysfunction (e.g. irritable bowel syndrome), autoimmune disorders, and fibromyalgia ¹⁸ ¹⁹ ²⁰.

There are different pathophysiological processes that lead to different subtypes within POTS. The subtypes of POTS can help in the understanding of the mechanisms that lead to the autonomic dysfunction and symptoms seen in the condition.

It is important to note that among the medical community there are not established medical definitions for each subtype that are uniformly accepted ²¹.

Also, patients often do not fit into just one subtype. Some medical professionals will not give patients a subtype at their time of diagnosis. This is because treatment often needs to be individualized to each patient and sometimes people exhibit findings from several subtypes ²² ²³.

Nevertheless, we will share the current understanding of the different subtypes.

The main POTS subtypes are Hyperadrenergic POTS (sometimes referred to as “Hyper-POTS”), Neuropathic POTS, Hypovolemic POTS, and immune-mediated or autoimmune POTS ²⁴ ²⁵.

Hyperadrenergic POTS - Hyperadrenergic POTS can be characterized by excessive tachycardia upon standing, an increase in systolic blood pressure of more than 10 mmHG, and elevated standing norepinephrine levels ²⁶ of 600 pg/mL or more ²⁷. Patients with hyperadrenergic POTS may also experience symptoms of sympathetic activation such as palpitations, sweating, nausea, and abdominal pain ²⁸.  Hyperadrenergic POTS may be secondary to another form of POTS like hypovolemic or neuropathic ²⁹.

Neuropathic POTS - Patients with neuropathic POTS often have some dysfunction with sympathetic denervation, usually a small fiber neuropathy ³⁰. They can present with patchy areas of skin in the legs/feet where they do not sweat ³¹ ³². Sympathetic denervation seen in neuropathic POTS can lead to increased blood pooling in the lower extremities and in the abdomen ³³. The blood pooling results in less blood being able to make it back up to the heart, so sympathetic activation then leads to an increased heart rate. ³⁴

Hypovolemic POTS - Hypovolemic POTS refers to patients who have a deficit in blood volume ³⁵.  Researchers have found that some  people with POTS can have approximately a 13% reduction in plasma volume compared to healthy individuals ³⁶. It is believed that these individuals might have dysregulation of the renin-angiotensin-aldosterone (RAA) system and decreased angiotensin II metabolism contributing to low fluid volume and impaired sodium retention ³⁷ ³⁸. The RAA system works to elevate blood volume and arterial tone by increasing sodium reabsorption, water reabsorption, and vascular tone ³⁹. As noted above, hypovolemia can cause/appear like hyperadrenegic POTS. In these people, the body compensates for the decreased blood volume by increasing central sympathetic activation.

Immune-mediated POTS - Some patients report symptom onset after an acute viral illness or along with autoimmune conditions, suggesting that autoimmune factors could play a role in the development of POTS. ⁴⁰ ⁴¹. Patients with POTS do have a higher frequency of autoimmune disorders like Sjorgren syndrome, lupus, celiac disease, and rheumatoid arthritis ⁴² ⁴³. Studies have reported autoantibodies and non-specific autoimmune markers in people with POTS, however, more research is needed to understand the impact of those antibodies ⁴⁴.

The current “gold standard” for diagnosing POTS is the Tile Table Test (TTT) but some doctors also diagnose POTS with a poor man's tilt instead ⁴⁵.

Other tests are often also performed in route to diagnosing POTS in order to rule out other causes of orthostatic tachycardia (e.g. routine blood work, holter monitor, etc.) but are not required for POTS diagnosis ⁴⁶.

Also, some people with POTS will receive additional autonomic testing (e.g. QSART, plasma norepinephrine) but current guidelines do not list this as a routine recommendation ⁴⁷.

See the Diagnosis page for full details on the diagnosis of autonomic conditions. 

POTS can be managed with both pharmacologic and nonpharmacologic methods. Oftentimes treatment starts with lifestyle adaptations such as increasing salt and water intake, learning physical counter maneuvers to counteract symptoms, wearing compression garments, and exercise training ⁴⁸ ⁴⁹.

If non-pharmacologic lifestyle adaptations are not successful in reducing symptoms, then a pharmacological approach is considered through the use of medications.

Various medications can be prescribed to increase the fluid volume within the body (Fludrocortisone), increase constriction of blood vessels (Midodrine), and/or decrease heart rate (beta blockers) ⁵⁰ ⁵¹ ⁵²

Please note, these are examples of medications used in POTS treatment and not an all-inclusive list.

Postural Orthostatic Tachycardia Syndrome (POTS) by Brent P. Goodman, M.D. - YouTube GIBLIB

POTS: Therapeutic Options: Blair Grubb, MD- YouTube Dysautonomia International 

Diagnosis and Management of POTS, 2017- YouTube Dysautonomia International 

Postural Orthostatic Tachycardia Syndrome: JACC Focus Seminar- Journal of the American College of Cardiology. 

Barriers to Functioning in POTS- Occupational Therapy in Healthcare

Orthostatic Hypotension (OH)

Orthostatic Hypotension (OH) is defined as a drop in blood pressure with a change in position. In individuals with OH, the body is not able to appropriately compensate and maintain an adequate blood pressure to send blood to the brain when standing ⁵³.

OH can be acute (only occurring a few times and resolving) or chronic (lasting longer and occurring more frequently) ⁵⁴.

OH can also be asymptomatic (meaning one does not notice symptoms of the drop in blood pressure) or debilitating ⁵⁵ ⁵⁶ ⁵⁷.

  • Drop in systolic BP >20 mmHG OR drop in diastolic BP >10 mmHG within 3 minutes of standing (or with 60 degrees of tilt on a tilt table test)
    • This increases to a drop of >30 mmHG in systolic or >15 mmHG diastolic in individuals with supine hypertension

Orthostatic hypotension symptoms include ⁶⁰ ⁶¹ ⁶²:

  • Lightheadedness (dizziness) 
  • Syncope/pre-syncope
  • Fatigue
  • Blurred vision
  • Brain fog
  • Weakness
  • Nausea
  • Headache
  • Palpitations
  • Chest pain
  • Neck and shoulder pain
  • Shortness of breath

OH occurs in about 6% of the general population ⁶³.

However, that frequency increases with age and comorbidities. In those over 65 years old, the prevalence increases to around 20% ⁶⁴ ⁶⁵.

Orthostatic Hypotension can be classified as non-neurogenic OH and neurogenic OH (nOH).

  • Non-neurogenic OH is the most common form of OH. It is typically caused by hypovolemia (low blood volume), cardiac pump failure (problems with the heart pumping effectively), venous pooling (blood pooling in the lower extremities), and certain medications ⁶⁶. Non-neurogenic OH is frequently fully treated if the underlying cause is identified and is able to be addressed. An example of a cause that may not be able to be remedied is heart failure ⁶⁷ ⁶⁸ ⁶⁹.
  • Neurogenic Orthostatic Hypotension (nOH) occurs when there is an autonomic vasoconstrictor failure resulting from decreased norepinephrine signaling for vasoconstriction through the body ⁷⁰ ⁷¹. nOH is commonly seen in those who are older with neurodegenerative conditions such as Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and rarer forms of dysautonomia like multiple system atrophy (MSA), and pure autonomic failure (PAF) ⁷² ⁷³. These individuals have a consistent and severe drop in blood pressure upon standing due to the autonomic failure but may not have an appropriate increase in heart rate to compensate ⁷⁴ ⁷⁵

    Those with nOH typically experience more severe symptoms than those with nonneurogenic OH ⁷⁶. Some patients can experience hypotensive symptoms after eating meals ⁷⁷. Approximately half of the individuals with nOH experience elevated blood pressure upon lying down (supine hypertension) ⁷⁸. Supine hypertension can sometimes lead to hypertensive emergencies and nocturnal pressure diuresis (frequent urination at night) ⁷⁹ ⁸⁰ ⁸¹. This nocturnal diuresis can then worsen orthostatic symptoms upon standing due to fluid reduction ⁸². The wide swing of blood pressure changes with positional alterations can decrease quality of life due to worsening symptoms, passing out, injuries from falling, and fear of falling. ⁸³ ⁸⁴ ⁸⁵.

Both forms of orthostatic hypotension can present as initial, classic, or delayed ⁸⁶ ⁸⁷ ⁸⁸.

  • Initial OH involves a drop of blood pressure within about 15 seconds of standing.
  • Classic OH involves a drop of blood pressure within 3 minutes of standing.
  • Delayed OH involves a drop of blood pressure after 3 minutes of standing.

Diagnosis is typically made through assessing orthostatic vital signs. This can be done at the bedside with a poor man's tilt or by using a tilt table test ⁸⁹.

Other tests that are sometimes used to distinguish neurogenic versus non-neurogenic OH include: Valsalva maneuver, autonomic reflex screen, ambulatory blood pressure monitoring, thermoregulatory sweat test, measurement of supine and standing norepinephrine, and 24-hour urinary sodium ⁹⁰

 See DIAGNOSIS PAGE for more information about diagnostic tests used for dysautonomia.

Many of the treatments for nOH and chronic, symptomatic non-neurogenic OH are similar. This includes pharmacologic and nonpharmacologic methods that aim to help reduce symptoms, improve orthostatic blood pressure without exacerbating supine hypertension, and improve standing time ⁹¹ ⁹².

Nonpharmacologic treatments center around avoiding large meals, limiting alcohol intake, increasing fluid intake to balance fluid losses, increasing the amount of sodium ingested (through dietary intake and/or supplements), compression garments stockings and abdominal binders, counter maneuvers to help increase blood pressure, and an exercise program focused on conditioning and core strength ⁹³ ⁹⁴ ⁹⁵. Additionally, increasing the head of the bed at night can help reduce supine hypertension, nocturnal diuresis, and sodium loss due to the nocturnal diuresis ⁹⁶ ⁹⁷ ⁹⁸. Decreasing the consumption of diuretic beverages such as coffee, tea, sodas, and alcohol will help retain fluid volume that would have been lost through urination ⁹⁹.

 Medications that focus on increasing fluid volume (fludrocortisone), constricting blood vessels (midodrine), and improving neurotransmission of acetylcholine which triggers the reflex that controls blood pressure (Mestinon) ¹⁰⁰ ¹⁰¹. Droxidopa has been FDA-approved for neurogenic orthostatic hypotension ¹⁰².

In the case of acute, non-neurogenic OH, treatment generally involves treating the underlying cause, which will usually then resolve the OH ¹⁰³. If it cannot be resolved, then the strategies above are recommended. 

Treatment of nOH is often complicated by supine hypertension and other factors.

For example, efforts to increase blood pressure and fluid volume during the day can worsen supine hypertension at night, and treatments to reduce supine hypertension at night can worsen orthostatic intolerance during the day ¹⁰⁴. Factors that worsen or aggravate OH, such as the use of hypotensive medications, anemia, dehydration, and vitamin deficiencies, should be assessed and corrected ¹⁰⁵. Each patient with nOH needs to be evaluated as a whole and treated for their individual situation. With appropriate and ongoing evaluation and treatment, symptoms can lessen, and individuals with nOH can experience a better quality of life. 

Vasovagal Syncope (VVS)

Syncope, or fainting/passing out, is a common problem that can result from many different causes. It presents as a temporary loss of consciousness with the inability to maintain postural tone ¹⁰⁶. Some individuals are not able to determine the exact cause of their syncope, and many only have one episode in their entire life. Other individuals can have recurrent episodes of passing out, commonly caused by reflex syncope such as vasovagal syncope or cardiac syncope ¹⁰⁷

Vasovagal syncope (VVS), otherwise known as neurally mediated syncope (NMS), is a form of syncope where the autonomic nervous system suddenly fails to maintain an adequate vascular tone resulting in hypotension (low blood pressure) and bradycardia (low heart rate) causing temporary loss of consciousness ¹⁰⁸. Orthostatic stress is typically the main trigger for a vasovagal syncope episode ¹⁰⁹.

  1. The syncopal episode is triggered by standing for more than 30 seconds, pain, emotional distress, or other noxious stimulus.
  2. There is a drop in blood pressure and heart rate.
  3. Symptoms like sweating, warmth, and nausea are experienced.
  4. There is fatigue following the episode.

Syncope can be accompanied by a period where the individual experiences symptoms known as presyncope prior to losing consciousness.

Pre-syncope symptoms may include ¹¹¹ ¹¹²

  • Feelings of warmth
  • Claminess
  • Sweating
  • Flushing
  • Nausea
  • Graying of vision or vision loss
  • Changes in hearing 
  • Pallor (looking pale)

Usually while unconscious, the individual is motionless, however, fine and coarse myoclonic movements, such as tremors or jerking, have been seen in around 10% of cases ¹¹³ ¹¹⁴.

Unconsciousness typically only lasts 1-2 minutes but full recovery can be slow and take minutes to hours ¹¹⁵.  After the syncopal event, the individual experiences intense fatigue ¹¹⁶ ¹¹⁷.

Up to 40% of people faint at least one time in their life ¹¹⁷ ¹¹⁸.

Females faint more frequently than males ¹¹⁹. About 14% of all syncopal episodes are vasovagal in nature ¹²⁰.

The following diagnostic tests may be useful when vasovagal syncope is suspected:

  • Resting 12 lead ECG ¹²¹
  • Tilt table testing ¹²²
  • Holter monitor ¹²³
  • Cardiac stress test if syncope occurs during exertion ¹²⁴

For more details on the diagnostic tests listed here, please see our diagnosis page

Treatment for vasovagal syncope typically starts with education on the diagnosis and prognosis. Specifically, education should focus on avoidance of triggers like prolonged standing, warm environments, etc. Physical counterpressure maneuvers can be helpful for presyncopal episodes to avoid loss of consciousness. An increase in salt and fluid intake may be helpful in managing symptoms. If the syncope continues, medications may be required. Midodrine, fludrocortisone, beta blockers, and/or selective serotonin reuptake inhibitors (SSRIs) may be helpful. 

Vasovagal Syndrome- YouTube York Cardiology

Counterpressure maneuver for low blood pressure- YouTube Arrhythmia Alliance

Neurocardiogenic Syncope- PubMed 

Vasovagal Syncope- Mayo Clinic

Inappropriate Sinus Tachycardia (IST)

Inappropriate Sinus Tachycardia (IST) is a chronic condition where the individual’s heart rate is above 100 beats per minute (bpm) at rest ¹²⁶.

Typically, a normal heart rate is between 60-100 beats per minute (bpm) ¹²⁷.

The word “sinus” refers to a sinus heart rhythm, which is the normal, healthy type of heart rhythm ¹²⁸.

This means that in IST, the heart is beating in its normal rhythm but is consistently beating at a higher than normal rate.

  • Average heart rate must be above 90 bpm for a 24 hour time period, including rest 
  • The heart rate must be in a sinus rhythm.   
  • Other causes of tachycardia must be ruled out.
  • The patient must experience distressing symptoms of palpitations

Unlike many of the other forms of dysautonomia, IST is not a form of orthostatic intolerance ¹³⁰.

This means that the symptoms and elevated heart rate are not dependent on position.

However, with IST minimal exertion (regardless of positional changes) can cause the heart rate to increase excessively ¹³¹ ¹³²

The most prominent symptom of IST is palpitations ¹³³ ¹³⁴.

Other symptoms include: weakness, fatigue, dizziness, exercise intolerance, shortness of breath, presyncope, and syncope ¹³⁵ ¹³⁶ ¹³⁷.

According to recent estimates, 1.2% of the population has IST ¹³⁸.

Diagnosis of IST is a diagnosis of exclusion, meaning other causes of high heart rate are looked into and excluded prior to getting the diagnosis of IST ¹³⁹ ¹⁴⁰ ¹⁴¹.

The most common tests used to diagnose IST are a 12 lead EKG and a 24 hour holter monitor ¹⁴².

See Diagnosis Page for further information on common diagnostic tests for autonomic disorders.

As with many other forms of dysautonomia, first line treatments for IST are lifestyle changes which include avoiding triggers of IST and stimulant medications ¹⁴³.

Beyond this, some medications that lower heart rate are often used to manage symptoms (particularly ivabradine) ¹⁴⁴ ¹⁴⁵. Ivabradine may also be used in collaboration with a beta-blocker ¹⁴⁶.

Sinus node modification in routine cases is not recommended by the current consensus statement for IST ¹⁴⁷.

Like many other forms of dysautonomia, more research is needed in this area. 

Inappropriate Sinus Tachycardia- YouTube York Cardiology. 

Inappropriate Sinus Tachycardia- Arrhythmia Alliance

Autoimmune Autonomic Ganglionopathy (AAG)

Autoimmune Autonomic Ganglionopathy (AAG), also known as acute pandysautonomia or idiopathic subacute autonomic neuropathy, is a rare form of dysautonomia ¹⁴⁸.

Some patients can have a rapid onset, while others have a more progressive presentation of symptoms ¹⁴⁹.

Symptoms are representative of autonomic failure of the sympathetic, parasympathetic, and enteric nervous systems ¹⁵⁰.

The most prevalent symptom associated with AAG is orthostatic hypotension (OH) ¹⁵¹.

Other symptoms may include ¹⁵²:

  • Dry eyes and mouth
  • Adie's pupil (tonic, sluggishly reactive pupils)
  • Gastroparesis
  • Neurogenic bladder (bladder dysfunction which may include overflow incontinence, frequency, urgency, urge incontinence, and retention) ¹⁵³ ¹⁵⁴
  • Paresthesia (a burning or prickling sensation in the extremities) 

AAG usually affects patients during their middle ages, and affects females more often than males ¹⁵⁵.

AAG can be diagnosed after a thorough history, medical examination, and autonomic testing ¹⁵⁶.

Some patients with AAG have high levels of the antibodies for the ganglionic nicotinic acetylcholine receptor (gAChR) ¹⁵⁷. It is believed that these antibodies damage the receptors in the autonomic ganglia, a part of the peripheral autonomic nerve fiber.

This interferes with autonomic transmission, resulting in the autonomic failure ¹⁵⁸ ¹⁵⁹.

Treatment of AAG is targeted at the antibody-mediated pathology, though there is no clear established treatment protocol.

Treatment for this form of dysautonomia is usually focused on treating associated symptoms ¹⁶⁰ ¹⁶¹.

The first treatment often used with AAG is antibody depletion through plasma exchange and intravenous immunoglobulin (IVIG) ¹⁶². Immunosuppressant medications and corticosteroids can be used in conjunction with the antibody depletion ¹⁶³.

Nonpharmacologic and pharmacologic treatment of OH and artificial tears and saliva for dry mouth and eyes can be used to treat specific symptoms ¹⁶⁴ ¹⁶⁵.

Some patients experience a spontaneous recovery without treatment, though for many, recovery is often incomplete and they experience some level of symptoms throughout their life ¹⁶⁶.

Autoimmune Autonomic Ganglionopathy- Steven Vernino, MD, PhD- YouTube Dysautonomia International 

Rare Dysautonomias with Dr. Glen Cook- YouTube Dysautonomia International 

Autoimmune Autonomic Ganglionopathy- Genetic and Rare Diseases Information Center

Baroreflex Failure (BF)

Baroreflex failure (BF) is a rare form of autonomic dysfunction where the baroreflex mechanisms are not working properly. 

Baroreflexes are important for the regulation of blood pressure ¹⁶⁶. When activated, the baroreflex sends electrical signals to the brain where it is combined with other input from the body ¹⁶⁷.

When blood pressure is too high, the baroreflex activates the parasympathetic nervous system and inactivates  the sympathetic nervous system ¹⁶⁸. The parasympathetic nervous system activation will decrease the heart rate.

The sympathetic nervous system inactivation will cause a decrease of the heart rate and stroke volume, and cause vasodilation of blood vessels.

The opposite happens when blood pressure is too low. 

In those with baroreflex failure, there is damage to the baroreflex structures responsible for sending information through nerve impulses toward the central nervous system and brain (afferent nerves) ¹⁶⁹. 

In baroreflex failure, the brain is not able to get the signals from the body about blood pressure status and therefore cannot regulate it well ¹⁷⁰

It is often caused by trauma sustained from extensive neck surgery or radiation of the neck with certain cancer therapies ¹⁷¹.

In some patients the exact cause cannot be determined ¹⁷² ¹⁷³ ¹⁷⁴. Onset can be abrupt or more gradual, with abrupt onset more noted with neck surgeries ¹⁷⁵ ¹⁷⁶.

  • Hypertension
  • Fluctuating blood pressure
  • Hypotension
  • Syncope
  • Tachycardia 
  • Bradycardia
  • Headache
  • Flushing

Baroreflex failure presents with blood pressure fluctuations throughout the day and may include hypertensive (high blood pressure) episodes and hypotensive (low blood pressure) episodes ¹⁷⁸.

During the hypertensive episodes, patients can experience blood pressure in the range of 170–280/110–135 mmHg high heart rates, feelings of warmth or flushing, headache, and sweating ¹⁷⁹. These episodes are often triggered by psychological stress, emotions, physical exercise, and pain.

Hypotensive, or low blood pressure episodes are less common but may involve bradycardia (decreased heart rate) and presyncope symptoms ¹⁸⁰ ¹⁸¹ ¹⁸².

It is important to note that orthostatic hypotension is typically not a symptom of baroreflex failure, but instead may be a sign of pure autonomic failure. Individuals with baroreflex failure can exhibit orthostatic hypotension if they are volume-depleted and treated with sympatholytic medications ¹⁸³.

Baroreflex failure is a rare form of dysautonomia and impacts fewer than 200,000 people in the USA ¹⁸⁴.

Baroreflex failure is diagnosed through a thorough history, physical examination, ruling out other conditions, assessing heart rate and blood pressure in response to medications ¹⁸⁵, venous plasma norepinephrine testing ¹⁸⁶, and autonomic testing ¹⁸⁷.

Autonomic testing may include ¹⁸⁸:

  • Ambulatory blood pressure testing (the only test to assess the absence of the baroreflex function) 
  • Valsalva maneuver (assessing absence of reciprocal changes in heart rate)
  • Cold pressor test (assessing for an exaggerated pressor response)

The main goal of treatment for those with BF is preventing extreme high blood pressures. Medications, such as clonidine, have been used to help reduce blood pressure ¹⁸⁹ ¹⁹⁰.

A secondary goal is to reduce the symptoms of hypotension, or low blood pressure episodes, if necessary ¹⁹¹ ¹⁹². Fludrocortisone may be helpful in meeting that goal ¹⁹³ ¹⁹⁴.

Some individuals have also needed pacemakers if they experience hypotensive, bradycardic episodes ¹⁹⁵.  Discussions with your provider should occur on how other medications can interact with the body’s ability to regulate and control blood pressure with BF ¹⁹⁶ ¹⁹⁷. Certain medications are contraindicated, or should not be taken due to potential harm ¹⁹⁸. 

Baroreflex Failure- Vanderbilt University

Regulation of blood pressure with baroreceptors |NCLEX-RN|- YouTube Khan Academy 

Baroreflex Regulation of Blood Pressure- Alila Medical Medical

21.4 Baroreflex- YouTube UChicago Online.

Familial Dysautonomia (FD)

Familial Dysautonomia (FD) is also known as Riley-Day Syndrome.

This is a rare genetic disorder and only about 350 people live with FD worldwide ¹⁹⁹.

FD occurs almost exclusively in Ashkenazi Jews, although it can occur in people of any nationality or race.

FD is an autosomal recessive disorder which means the chances of inheriting FD are 25% when both parents are carriers ²⁰⁰.  

  • Decreased pain sensitivity
  • Unstable blood pressure and body temperature regulation
  • Autonomic crisis (cyclical vomiting with very high blood pressure, high heart rate, sweating, and fever) 
  • Absence of tears
  • Inability to suck or swallow (this may cause the need for a feeding tube)
  • Poor growth
  • Other respiratory, cardiovascular, orthopedic, digestive, and vision problems

Those with familial dysautonomia should refer to the Familial Dysautonomia Foundation for more information  

Note: Familial Dysautonomia is a distinct form of dysautonomia. There is currently speculation about possible genetic factors impacting other forms of dysautonomia (i.e. people noticing several people in their family having dysautonomia).

This is NOT the same thing as having FD.

Familial Dysautonomia- Genetic and Rare Diseases Information Center

What is FD- Familial Dysautonomia Now Foundation 

Screening for Familial Dysautonomia- NYU Langone

Riley Day Syndrome- Mount Sinai

Pure Autonomic Failure (PAF)

Pure Autonomic Failure (PAF) is a rare form of dysautonomia ²⁰¹. It is also known as Bradbury-Eggleston Syndrome and is a primary dysautonomia.

PAF causes deterioration of autonomic nervous system cells and therefore causes overall autonomic nervous system dysfunction ²⁰².

Orthostatic hypotension is a key feature of PAF. It is typically severe and may cause dizziness, fainting, and syncope ²⁰³ ²⁰⁴.

Other symptoms may include genitourinary, bowel, and thermoregulatory dysfunction ²⁰⁵. Also, recent research has shown a relationship between PAF and later developing other conditions such as MSA, parkinson's disease, and dementia ²⁰⁶.

The average age of onset is middle age and it is more common in males than females ²⁰⁷.

In one study, participants reported the following symptoms ²⁰⁸:

  • Orthostatic hypotension 
  • Supine hypertension (50%) 
  • Genitourinary dysfunction (50%) 
  • Constipation (58%)
  • Sweating abnormalities (44%)

Pure autonomic failure is a rare form of dysautonomia and impacts fewer than 200,000 people in the USA ²⁰⁹.

Official diagnostic criteria for PAF, per consensus statement, have not been updated since 1996 ²¹⁰.

The diagnostic criteria are fairly vague and include: neurogenic orthostatic hypotension, other autonomic symptoms often are also present, and that there are no other neurological symptoms ²¹¹.

Neurogenic orthostatic hypotension is diagnosed through assessing orthostatic vital signs ²¹².

PAF is often diagnosed at facilities with access to a full range of complex autonomic function tests in order to help clarify diagnosis. This includes measuring plasma catecholamine levels, valsalva maneuver, baroreflex testing, QSART, etc. ²¹³.

Treatment for PAF involves symptom management, specifically controlling blood pressure fluctuations ²¹⁴.

To address orthostatic hypotension, non pharmacological measures include increasing fluid intake, salt intake, exercise, elevating the head of the bed, and using compression garments ²¹⁵.

Medications aimed to address orthostatic hypotension include midodrine, droxidopa, fludrocortisone, and pyridostigmine ²¹⁶ ²¹⁷. Supine hypertension may be treated with nitroglycerin, or clonidine ²¹⁸.

Other symptoms like constipation are managed first with non pharmacological means like increasing water and fiber intake ²¹⁹ ²²⁰.

Pure Autonomic Failure- Genetic and Rare Diseases Information Center [GARD]

Overview of Autonomic Failure- American Autonomic Society & The Dysautonomia Project 

Pure Autonomic Failure- National Organization for Rare Diseases

Multiple System Atrophy (MSA)

Multiple System Atrophy is a rare, degenerative neurological disease that causes autonomic dysfunction and other neurological symptoms ²¹⁷.

The criteria for diagnosis of MSA is as follows ²¹⁸:

  • Autonomic failure involving urinary incontinence or an orthostatic decrease of blood pressure within 3 mins of standing by at least 30 mm HG systolic or 15 mm HG diagnosis and
  • Poor symptom response to the medication levodopa or a cerebellar syndrome including gait ataxia with cerebellar dysarthria, limb ataxia, or cerebellar oculomotor dysfunction

MSA is diagnosed through eliminating other diagnoses and is based on clinical features (symptoms)

There are two subtypes of MSA based on the most predominant symptoms: MSA-P (predominant Parkinsonism) and MSA-C (predominant cerebellar ataxia) (The MSA Coalition, 2020) ²¹⁹. MSA-P is more common than MSA-C ²²⁰.

About 75% of those with MSA experience neurogenic orthostatic hypotension (nOH) ²²¹.

In MSA-P, the most common signs and symptoms include ²²²:

  • Rigid muscles
  • Resting tremor
  • Difficulty swallowing
  • Slow movement
  • Difficulty with balance and posture

In MSA-C, the most common signs and symptoms include ²²³:

  • Difficulty coordinating walking
  • Poor hand coordination
  • Slurred speech
  • tremors

 It is estimated that only .6/100,000 people have this condition. ²²⁴

Treatment for MSA is focused on symptom management. Non-pharmacological treatment of autonomic symptoms are similar to other types of dysautonomia and include compression stockings, adequate salt and water intake, head up tilt at night, eating small meals throughout the day, etc. 

For parkinsonism, medications may include Levodopa or Amantadine. For orthostatic hypotension, Fludrocortisone or Midodrine may be used. For urge incontinence, oxybutynin may be used. For frequent urination at night, desmopressin may be used. 

The Multiple Systems Atrophy Coalition is a non-profit dedicated to the MSA community. Please see their website for additional MSA-specific information and content.

Multiple Systems Atrophy- Multiple Systems Atrophy Coalition

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