24th May 2023

A 14-year-old presents to the emergency department with headache and lethargy

A 14-year-old presents to the emergency department with headache and lethargy. Her mother tells you that last week she had noticed some slurred speech which resolved in a few hours, so thought nothing of it. The child is known to have sickle cell disease but has otherwise been well.

What investigation most likely yields the diagnosis?