What are autonomic disorders?

Autonomic disorders are often considered functional conditions, which means that there is not a clear cause for the patient’s symptoms. Endoscopy, X-rays or blood tests may come back normal. Often, these disorders affect the part of the nervous system that controls our “automatic” body functions, such as our blood pressure, heart rate, sweating, temperature, bowel and bladder. We treat children with autonomic disorders who are experiencing gastrointestinal complaints such as nausea and abdominal pain, along with other symptoms such as dizziness, fatigue, headaches and joint hypermobility.

Autonomic disorders are often under-recognized. Sometimes people might assume that the pain is in a child’s head or that he or she is simply trying to avoid school, and a child’s complaints might be dismissed for some time before the correct diagnosis is made.

Causes of autonomic disorders

Doctors don’t yet know what causes problems in the autonomic nervous system, but symptoms often start after an acute illness. Researchers at Children’s Hospital continue to study the potential causes of functional and autonomic disorders.

Autonomic disorders occur

These disorders are relatively common. For example, about 10 to 15 percent of children who report abdominal pain have pain that cannot be easily explained by the routine tests or studies that doctors perform.

Autonomic disorders development

Although doctors don’t know for sure, they suspect that patients with autonomic and functional disorders are predisposed in some way. It could be related to genetics, stress at an early age or changes in gut bacteria. Children with these disorders often develop chronic abdominal pain after a significant stressful event, such as an acute illness or a psychological stressor like a parent’s divorce. Chronic pain could start after something as simple as the common flu.

Symptoms of autonomic disorders

Children with autonomic disorders may have one or more of these symptoms:

  • Dizziness
  • Lack of energy
  • Fainting
  • Nausea
  • Abdominal pain

Postural orthostatic tachycardia syndrome, also known as POTS, is an autonomic disorder that most often affects teenagers. The main symptom of POTS is orthostatic intolerance due to a significantly reduced volume of blood returning to the heart after a patient stands up from a lying position. Symptoms may include:

  • Lightheadedness
  • Dizziness
  • Extreme lack of energy

Often these children will also have migraines, gastrointestinal problems (such as nausea, vomiting and abdominal pain), aches and pains all over the body that strike after an acute illness, and near fainting or fainting.

Risk of developing this condition

We do not know how many children or teens suffer from these disorders, but we do know that they affect mainly teen girls. We have noticed that these conditions may run in families, but we still don’t understand the factors that may predispose children to these disorders.

Concerns of autonomic disorders

Although these disorders are not life threatening, they are extremely disabling. Many affected children drop out of school and extracurricular activities as the symptoms force them to become homebound. A high-achieving child who is a gifted athlete might suddenly find him or herself unable to complete even 10 minutes of aerobic exercise. An autonomic disorder can have a dramatic and detrimental effect on a child’s life.

Diagnosis and evaluation of autonomic disorders

It’s important for primary care physicians to believe a child’s symptoms even if the child appears healthy. After conducting a physical exam and obtaining a detailed medical history, your physician may refer you to the autonomic lab for autonomic testing.

Treatment for functional autonomic disorders

Treatment depends on the severity of the patient’s problem. Increased physical activity, increasing the amount of water and salt in the diet, and cognitive behavior therapy might be all that’s needed to treat some very mild disorders of the autonomic nervous system. It is important to recognize that besides these functional autonomic disorders, there are other disorders of the autonomic nervous system that can be much more severe, though they are very rare in children. These include congenital central hypoventilation syndrome and familial dysautonomia, also known as Riley-Day syndrome.

Researchers think that functional disorders, including functional autonomic disorders, could be caused by the brain responding to a stimulus in the wrong way. For example, the brain could perceive every movement of the intestine as painful, even though most people don’t realize those movements are happening. Cognitive behavior therapy, led by a psychologist who has special training in CBT, can help “rewire” a patient’s brain to improve his or her pain response.

With patients who have POTS, the first step may be to increase salt and fluid consumption, which expands the volume in your child’s blood vessels so he or she will be less likely to feel dizzy and faint. Exercise can also be incredibly effective because it improves the efficiency of blood pumping, among other positive benefits.

In some cases, doctors may also prescribe medications to help alleviate your child’s symptoms, including chronic dizziness, nausea and pain. Gastric pacing can also help relieve nausea and pain.

After the treatment

Treatment can help children manage their symptoms so that they can resume normal activities.

Contacting a physician

If your child complains of belly pain, dizziness, nausea or other symptoms, you should see your pediatrician. If routine tests don’t indicate a clear diagnosis, your pediatrician may refer you to a GI specialist for autonomic testing.

Long-term outlook for autonomic disorders

The outlook is usually good for most children with functional gastrointestinal and autonomic disorders. Some patients might outgrow their symptoms completely while others may need to continue treatment to manage their symptoms.

Living with functional autonomic disorders

Following your doctor’s treatment recommendations — including increasing your child’s regular exercise, water consumption and salt in the diet if recommended by your doctor — can go a long way toward helping your child feel better.