Exam MCCQE Topic 1 Question 207 Discussion

This child experienced a first unprovoked generalized tonic-clonic seizure that resolved spontaneously and now has a normal neurologic examination and stable vital signs. MCCQE objectives emphasize that the immediate priority after a first seizure is to identify reversible metabolic causes , particularly hypoglycemia and electrolyte abnormalities (e.g., hyponatremia, hypocalcemia). Therefore, urgent serum electrolytes (and glucose) are indicated.
Neuroimaging (CT or MRI) is not urgently required in a neurologically normal child without focal deficits, trauma, persistent altered consciousness, or signs of increased intracranial pressure. MRI may be arranged later for further evaluation if clinically indicated. Electroencephalography is useful in outpatient follow-up to assess seizure type and recurrence risk but is not an emergency test. Lumbar puncture is reserved for suspected central nervous system infection (e.g., fever, meningeal signs, altered mental status), which are absent here.
Thus, immediate laboratory evaluation for metabolic derangements is the appropriate urgent investigation.