Understanding the Mysteries of POTS and Other Autonomic Disorders

For eight months after the birth of her daughter in 2016, Fidji Simo felt weak, tired, lightheaded, and dizzy. “My heart rate would shoot through the roof as soon as I sat or stood up. I also passed out a lot and had what felt like electricity running through my muscles,” says Simo, who sometimes fainted up to five times a day.

She saw many doctors, but no one could pinpoint the cause of her increased heart rate or frequent fainting spells. One doctor, Simo recalls, said she was “just a new mom who needs more sleep.”

“I have operated on four to five hours of sleep a night my whole life and never had a problem,” says Simo, 35, who lives in northern California and is the head of the Facebook app. “I knew that not sleeping enough was not the cause.”

Her symptoms went away eventually, but they returned three years later when she had surgery to treat endometriosis. For the next seven months Simo, her primary care doctor, and a neurologist worked to put the pieces of her diagnostic puzzle together. She had blood drawn to check her norepinephrine levels and underwent tests to determine whether her body was sweating at the right rate and to measure her blood pressure and heart rate responses to changes in gravity. Based on the results, Simo was diagnosed with postural orthostatic tachycardia syndrome (POTS), a disorder in which too little blood returns to the heart when the body goes from lying down to sitting or standing. The condition is more common in women than in men and can be triggered by pregnancy, surgery, trauma, or a viral illness.

POTS is a form of dysautonomia, an umbrella term for conditions that affect the autonomic nervous system (ANS). “The ANS controls things like blood flow to different organs, heart rate, breathing, body temperature, and digestion—automatic functions of the body that occur involuntarily, in the background,” says William P. Cheshire, MD, FAAN, professor of neurology at Mayo Clinic in Florida. “Autonomic nerves reach every organ and help regulate its function in harmony with other organs or in response to stress. With dysautonomias, there’s some disturbance in that system. The effects can be systemic or confined to one area.” People with dysautonomia may experience erratic heart rate, problems with blood pressure regulation, orthostatic hypotension (feeling dizzy or faint when standing up due to decreased blood flow from the heart to the brain), heat sensitivity or intolerance, and bladder dysfunction.

More than 70 million people worldwide live with various forms of dysautonomia, including POTS (which commonly affects females between the ages of 15 and 50), neurocardiogenic syncope (fainting caused by low blood flow to the brain), pure autonomic failure (dysfunction in processes controlled by the autonomic nervous system, such as blood pressure), familial dysautonomia (an inherited condition primarily affecting Ashkenazi Jews), and multiple system atrophy (a rare disease that leads to a life expectancy of seven to 10 years following onset of symptoms).

Symptoms vary depending on the type of dysautonomia, but they can include fatigue, brain fog, joint pain, tingling and numbness, headaches, dizziness, irregular sweating, and dramatic changes in blood pressure.

Simo’s flare-ups come in waves, last a couple of weeks, and are usually triggered by an infection or a virus. If her daughter has a runny nose or mild cold, Simo has to be extra careful not to catch the cold as that also can be a trigger. Simo’s symptoms often include vertigo or severe gastroparesis—muscle damage that slows the stomach’s ability to move food through the digestive tract.

POTS can be as disabling as congestive heart failure or chronic obstructive pulmonary disease, and up to 25 percent of people who have it are unable to work. Simo has managed her symptoms well enough to continue in her job, and working from home during the pandemic has made it easier. She also has the support of her husband, a stay-at-home parent who takes care of their 5-year-old daughter. “I’m lucky that I can keep my job and have support from my family and my employer,” she says. “Not everyone is that lucky, and that’s why our medical system and employers need to do better.”

Risk Factors

Experts aren’t sure why people develop dysautonomias, but a viral infection can sometimes “switch on” these disorders when the immune system gets activated. In fact, about 50 percent of patients with POTS recall having a virus or bacterial infection right before experiencing symptoms.

Unlike familial dysautonomia, which is a rare genetic disorder, the more common forms of dysautonomia do not follow typical inheritance patterns. “There are likely certain sets of genes that may predispose patients toward POTS and the other more common autonomic disorders,” says Svetlana Blitshteyn, MD, director of the Dysautonomia Clinic in Buffalo, NY, and clinical assistant professor of neurology at the University at Buffalo Jacobs School of Medicine and Biomedical Sciences. “We don’t know what these genes are yet, but two recent studies suggested that human leukocyte antigen types associated with autoimmune disorders may be more common in people with POTS.”

POTS also may be an autoimmune disorder, says Brent P. Goodman, MD, chief of the neuromuscular division in the department of neurology at Mayo Clinic in Phoenix. “There are specific clinical clues we look for, such as a personal history of [other] autoimmune diseases, a recent infection, family history of autoimmune disease, and significant and unintentional weight loss around the time of symptoms. We need more reliable biomarkers to establish who has an underlying autoimmune mechanism and whether that mechanism is active.”

These mysteries and a general lack of understanding about dysautonomia make diagnosis difficult. “Disorders of the autonomic nervous system can be nuanced and have to be interpreted with some knowledge about how the system works,” says Dr. Cheshire. “These disorders are complicated and typically are not taught in any depth in medical school.”

The few experts who specialize in the field look for prominent characteristics and symptoms, including extreme dizziness and frequent fainting. A common diagnostic tool is a tilt table, which measures the patient’s heart rate and blood pressure while the patient is lying down and again when upright.

Arriving at a specific diagnosis based on symptoms alone can be challenging, as some symptoms of autonomic disorders can overlap with those of other diseases. For example, patients with multiple system atrophy may have slow movements, poor balance, a shuffling gait, and lack of facial expression—all characteristics of Parkinson’s disease, says David S. Goldstein, MD, PhD, who directs the autonomic medicine section in the intramural research program at the National Institutes of Health.

Patients with pure autonomic failure (PAF) often go untreated for years. “PAF can evolve into Parkinson’s disease or Lewy body dementia, so early diagnosis and treatment are critical,” says Dr. Goldstein. “In degenerative diseases like these, you have to recognize that most of the damage has already been done by the time the patient notices something wrong, so the hope for the future is in identifying the disease process before people have symptoms.”

For people with familial dysautonomia, genetic testing can determine whether they carry the mutant gene for the disorder. “A mutation in the IKBKAP gene causes this type of dysautonomia, almost exclusively among Ashkenazi Jews,” says Dr. Cheshire.

Raising Awareness

Patients with dysautonomia, especially POTS, often look healthy, so they may not get the treatment they need. Their symptoms could also be dismissed or overlooked if the doctor is unfamiliar with POTS, says Lauren Stiles, research assistant professor of neurology at New York’s Stony Brook University School of Medicine. She is also president of the nonprofit Dysautonomia International, which aims to increase awareness through lectures and physician education and to raise funds for research.

“It’s really about training as many clinicians as possible, so they can help reduce the delay in diagnosis,” says Stiles, whose own diagnosis of small fiber neuropathy and POTS took two years to attain. “With the help of new research and educational outreach, the rate of diagnosis is actually improving quite a bit,” she says. Her organization has funded more than $2 million in POTS research in the past few years and regularly hosts physician and patient education programs.

“Diagnosis used to be delayed by an average of six to seven years and longer—now it’s usually less than four years,” says Dr. Blitshteyn. But patients still have to be proactive. “It’s imperative that patients—especially women, who know their own bodies best—advocate for themselves,” says Simo. “Don’t let the authority that doctors tend to wield interfere with a diagnosis and proper care.”

Treatment of dysautonomia symptoms often starts with a nonpharmacologic approach. “After we diagnose POTS, we ask patients to drink a lot of fluids, increase sodium intake, and wear compression stockings and abdominal binders,” says Dr. Blitshteyn. “We may prescribe medications, such as beta-blockers and others, to help regulate heart rate and blood pressure.” POTS and other types of dysautonomia are incurable, but treatment can improve symptoms and quality of life, Dr. Blitshteyn says. She and her team are working on a study to show whether a gluten-free diet may help ease gastrointestinal and other symptoms in patients with POTS.

Researchers continue to explore other therapies. “I think immunotherapy is going to be very important moving forward,” says Dr. Blitshteyn, citing several case studies that showed the benefits of immunotherapy in severe POTS. “And we certainly need more therapies and physicians who can diagnose and treat POTS. The more health care professionals are knowledgeable about these common autonomic disorders, the more patients will benefit.”

Funding for dysautonomia disorders is meager compared with less common but better-known diseases such as multiple sclerosis. “We need more funding, more research, and more studies to help us figure out how best to treat this,” says Stiles. “As a patient, it can feel like you’re in limbo, with limited options.”

“Once we understand the condition better, that should open up more treatment options,” Dr. Goodman adds. “It’s understandably very daunting and frustrating for patients. My advice for any patient is to advocate for yourself and remain hopeful.”

Since her diagnosis, Simo has been drinking plenty of water, sleeping at least seven hours every night, and going for a daily half-hour swim. If she doesn’t stick to this routine, her symptoms get worse. She still deals with fatigue, dizziness, and an upset stomach, but she’s learned how to handle her condition. “Sometimes I just have to tell my [co-workers], ‘Hey, I’m not feeling particularly well. I need to go lie down. Let’s do this meeting audio only.’”

Sharing her story is important too. “If I don’t talk about this, these types of diseases go unseen, and those who are completely disabled don’t have a voice,” Simo says. “I feel a huge sense of responsibility in telling my story, even though it’s still taboo for many top business leaders—especially women—to talk about their health. I want people to know that you can have one of the top jobs in an industry while managing an invisible illness. And if we want the research to move forward, we need more people talking about these diseases.”

Managing POTS Symptoms

The best way to treat postural orthostatic tachycardia syndrome (POTS) is to adopt these habits, says Svetlana Blitshteyn, MD, director of the Dysautonomia Clinic in Buffalo, NY, and clinical assistant professor of neurology at the University at Buffalo Jacobs School of Medicine and Biomedical Sciences.

  • Stay hydrated. Drinking at least 32 ounces of water per day can improve blood pressure response when you’re standing up.
  • Add salt. Consuming at least 3 to 5 grams of sodium chloride a day helps increase blood volume, which can boost blood pressure. Before adding more sodium to your diet, discuss your plan with your doctor.
  • Don’t stand for long. Standing for long periods of time can aggravate low blood pressure in some people with POTS. If you can’t avoid it, shift your weight from one foot to the other, point or flex the feet, and squeeze your glutes. Moving the lower half of your body pumps blood back to the heart.
  • Lay off alcohol. Boozy beverages are dehydrating and can worsen symptoms.
  • Wear compression garments. Compression stockings and abdominal belts may improve blood flow, which lessens the risk of blood pooling and low blood pressure.
  • Exercise carefully. Since fainting is a common symptom of POTS, people need to be safe when they exercise. Do activities during which you don’t stand, such as rowing, swimming, recumbent bicycling, Pilates, gentle stretching, yoga, and chair-based exercises.
  • Sleep soundly. Aim for at least seven hours of shut-eye each night. If you have gastrointestinal symptoms, try elevating your head while sleeping.

Source: Brain and Life

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