What is the next step in managing a patient with recurrent syncope, hyponatremia, and hypokalemia?

From the Guidelines

The most appropriate next step in management for this patient is electroencephalography (EEG). This 27-year-old transgender man presents with recurrent episodes of loss of consciousness accompanied by a prodromal abdominal sensation, post-ictal confusion, and urinary incontinence, which are classic features of seizures, specifically generalized tonic-clonic seizures. The description of a "funny sensation" in his stomach suggests an aura, which often precedes seizures. The loss of consciousness, lack of recall of the events, post-ictal state (taking several minutes to feel normal again), and urinary incontinence strongly point to seizure activity rather than syncope or other causes of transient loss of consciousness.

Key Considerations

• The patient's symptoms, such as the prodromal abdominal sensation and post-ictal confusion, are more indicative of seizure activity than syncope.
• The normal ECG makes cardiac causes less likely, and the clinical presentation is not consistent with orthostatic hypotension, sleep disorders, or psychological causes that would warrant the other management options listed.
• EEG is the gold standard diagnostic test for epilepsy and can detect abnormal electrical activity in the brain that would confirm this diagnosis, as suggested by 1.

Ruling Out Other Causes

• While the patient's electrolyte abnormalities (mild hyponatremia and hypokalemia) should be addressed, they are unlikely to be the primary cause of these episodes.
• The patient's family history of coronary artery disease and smoking history are important to consider, but the clinical presentation does not suggest a cardiac cause for the loss of consciousness.
• The patient's use of testosterone decanoate is also important to consider, but there is no clear link between this medication and the patient's symptoms.

Next Steps

• EEG should be performed to confirm the diagnosis of epilepsy and to guide further management.
• The patient's electrolyte abnormalities should be addressed, and the patient should be monitored for any changes in their condition.
• Further evaluation and management should be guided by the results of the EEG and other diagnostic tests, as suggested by 1.

From the Research

Diagnostic Approach

The patient's symptoms of fainting episodes, "funny sensation" in the stomach, and loss of bladder continence during these episodes suggest a possible diagnosis of syncope due to orthostatic hypotension.

• The patient's history and physical examination show no abnormalities, but the serum laboratory studies reveal a low sodium concentration and low potassium concentration.
• The ECG shows no abnormalities, which rules out cardiac syncope.

Next Step in Management

Based on the studies 2, 3, 4, 5, 6, the most appropriate next step in management would be to measure orthostatic vital signs.

• This is because orthostatic hypotension is defined as a reduction of systolic blood pressure of at least 20 mm Hg or diastolic blood pressure of at least 10 mm Hg within 3 minutes of standing 2.
• Measuring orthostatic vital signs would help to confirm the diagnosis of orthostatic hypotension and guide further management.
• The other options, such as cognitive behavioral therapy, CT angiography of the head and neck, electroencephalography, and polysomnography, are not directly relevant to the diagnosis of orthostatic hypotension.

Rationale

The studies 3, 4, 5, 6 emphasize the importance of measuring orthostatic vital signs in the diagnosis of syncope due to orthostatic hypotension.

• The European Society of Cardiology guidelines recommend performing an orthostatic challenge with active standing to detect orthostatic hypotension 3.
• The studies also highlight the importance of a thorough history and physical examination, including orthostatic assessment, in making the diagnosis of syncope 4, 5, 6.