What is the relationship between nausea and dysautonomia (Dysautonomic Syndrome)?

From the Guidelines

Nausea is a common symptom associated with dysautonomia, particularly in patients with Postural Orthostatic Tachycardia Syndrome (POTS), as evidenced by the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1.

Definition and Relationship

Dysautonomia refers to a group of conditions that affect the autonomic nervous system, which regulates various involuntary functions of the body, including heart rate, blood pressure, and digestion. Nausea in dysautonomia can be attributed to several factors, including:

• Delayed gastric emptying (gastroparesis) due to autonomic dysfunction, leading to food staying in the stomach longer than normal 1.
• Blood pressure fluctuations reducing blood flow to digestive organs, contributing to nausea.
• Disruption of normal signals between the brain and gut that regulate digestion.

Symptoms and Diagnosis

Symptoms of POTS, a form of dysautonomia, include:

• Frequent symptoms that occur with standing, such as lightheadedness, palpitations, and fatigue.
• Increase in heart rate of ≥30 bpm during positional change from supine to standing.
• Absence of orthostatic hypotension (>20 mm Hg reduction in systolic BP).
• Symptoms not associated with particular postures, such as bloating, nausea, diarrhea, and abdominal pain.

Treatment Options

Treatment for nausea associated with dysautonomia may include:

• Small, frequent meals low in fat and fiber.
• Staying well-hydrated.
• Medications like ondansetron (Zofran) or promethazine (Phenergan) for acute nausea.
• Prokinetic agents such as metoclopramide (Reglan) or domperidone to improve gastric emptying.
• Pyridostigmine (Mestinon) to help with overall autonomic function.
• Compression garments, adequate salt intake, and proper hydration to stabilize blood pressure and potentially reduce nausea.

Recommendations

It is essential to consult with a healthcare provider who specializes in dysautonomia for a personalized treatment plan, especially if nausea is severe or persistent 1.

From the Research

Relationship Between Nausea and Dysautonomia

• Nausea can be associated with dysautonomia, particularly in patients with orthostatic intolerance (OI) 2.
• A study found that 71% of patients with chronic idiopathic nausea associated with OI showed improvement in nausea symptoms after treatment with fludrocortisone 2.
• The relationship between nausea and dysautonomia may be related to a generalized disturbance of autonomic regulation, as suggested by the association of EGG abnormalities and OI in patients with nausea 2.
• Dysautonomia can manifest in various forms, including postural orthostatic tachycardia syndrome (POTS), neurogenic orthostatic hypotension (nOH), and chronic fatigue syndrome, which can all have different symptoms and treatment approaches 3, 4.
• Treatment of dysautonomia-associated symptoms, such as orthostatic hypotension, sialorrhea, constipation, urinary frequency, and erectile dysfunction, often requires a multidisciplinary approach and may involve medications such as fludrocortisone, midodrine, and droxidopa 5.

Diagnostic Challenges

• The diagnostic journey for individuals with dysautonomia can be hindered by symptom overlap with other conditions and limited access to autonomic specialists 6.
• The average time to diagnosis for dysautonomia patients is 7.7 years, which can contribute to morbidity and compound the psychological and economic burden of the condition 6.
• Common comorbid conditions, such as Ehlers-Danlos syndrome, mast cell disorders, and fibromyalgia, can contribute to the symptoms burden and confound the diagnostic process 6.

Treatment and Management

• Treatment of dysautonomia often requires a personalized approach, taking into account the underlying cause and severity of symptoms 3, 4.
• Medications such as fludrocortisone, midodrine, and droxidopa can be effective in managing symptoms such as orthostatic hypotension and nausea 2, 5.
• Lifestyle modifications, such as postural care, good hydration, and supervised physical activity, can also be important in managing dysautonomia symptoms 3.