What are the next steps for investigating a 26-year-old female with symptoms of dizziness, migraines, syncope (fainting), and nausea, with normal tilt table test, normal electrocardiogram (EKG), normal laboratory results, normal echocardiogram, and normal orthostatic vital signs?

From the Guidelines

For a 26-year-old female with dizziness, migraines, syncope, nausea, and normal initial workup (tilt table, EKG, labs, echo, orthostatics), the next investigative steps should focus on neurological and vestibular causes, as well as further cardiac evaluation.

Key Considerations

• The patient's symptoms of dizziness, migraines, syncope, and nausea, in conjunction with a normal initial workup, suggest the need for a comprehensive approach to diagnose potential underlying conditions.
• The normal tilt table test and orthostatic vital signs make orthostatic hypotension less likely, but do not rule out other causes of syncope, such as reflex syncope or postural orthostatic tachycardia syndrome (POTS) 1.
• Given the patient's age and symptom profile, it is essential to consider neurological and vestibular causes, as well as the possibility of intermittent cardiac issues not captured by standard testing.

Recommended Investigations

• Neurology consultation: for a comprehensive neurological examination and possible brain MRI with contrast to evaluate for structural abnormalities, demyelinating disorders, or vascular issues.
• Vestibular function testing: including videonystagmography (VNG) and audiometry to assess for vestibular disorders.
• 24-72 hour ambulatory cardiac monitoring: to capture potential intermittent arrhythmias that might have been missed on the standard EKG.
• Sleep study: to evaluate for sleep disorders that can contribute to these symptoms.
• Symptom diary: maintaining a diary to document triggers, duration, and associated factors would provide valuable diagnostic information.

Rationale

These investigations are prioritized because the constellation of symptoms suggests either a neurological disorder, vestibular dysfunction, or possibly an intermittent cardiac issue not captured on standard testing 1. The normal tilt table and orthostatics make orthostatic hypotension less likely but do not rule out other causes of syncope. The patient's symptoms and normal initial workup warrant a thorough evaluation to determine the underlying cause of her symptoms and to guide appropriate management.

Further Considerations

• The diagnosis of syncope and its management should be based on a thorough history, physical examination, and eyewitness observation, if available, as outlined in the guidelines for the evaluation and management of patients with syncope 1.
• The patient's symptoms may also be consistent with postural orthostatic tachycardia syndrome (POTS), which is characterized by a sustained increase in heart rate of ≥30 bpm within 10 min of moving from a recumbent to a quiet standing position, and symptoms that occur with standing, such as lightheadedness, palpitations, and fatigue 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Next Steps for Investigation

Given the symptoms of dizziness, migraines, syncope, and nausea in a 26-year-old female, with normal tilt table test, normal electrocardiogram (EKG), normal laboratory results, normal echocardiogram, and normal orthostatic vital signs, the next steps for investigation could involve:

• Further evaluation of orthostatic intolerance, as it is a potential cause of symptoms such as dizziness and syncope 2, 3
• Assessment of cerebral blood flow, as impaired regulation of cerebral blood flow in the upright posture can result in disabling symptoms 4
• Consideration of the patient's history of migraines, as migraineurs are at increased risk of subclinical and clinical ischemic brain lesions, and symptoms such as syncope and orthostatic intolerance may contribute to this risk 5
• Evaluation of other potential causes of symptoms, such as postural orthostatic tachycardia syndrome, orthostatic hypotension, and other forms of orthostatic intolerance 2, 3, 4

Diagnostic Considerations

Diagnostic considerations could include:

• Transcranial Doppler ultrasound, extracranial cerebral blood flow ultrasound, near infrared spectroscopy, and wearable devices to measure cerebral blood flow 4
• Structured interview to assess symptoms of orthostatic intolerance, such as frequent syncope and orthostatic intolerance 5
• Brain MRI scan to assess for brain lesions 5

Treatment and Management

Treatment and management considerations could include:

• Nonpharmacological and pharmacological methods to manage symptomatic orthostatic intolerance 2
• Countermeasures such as exercise, water drinking, mental arithmetic, cognitive training, and respiration training to improve orthostatic tolerance 6
• Early re-mobilization following bedrest confinement or bedrest to prevent orthostatic intolerance, falls, and falls-related injuries 6