Q. A 16 year-old boy presents to the ER with an unrelenting headache. It is throbbing and pulastile, radiates from the frontal region to the back left portion of the head. He began having headaches when he was 6 years old. They have varied in frequency over the past decade; initially they would occur a couple of times per week, then then became fairly quiescent, but over the past few years, he has been getting them monthly. They are associated with photophobia and phonophobia, and he usually goes to a dark, quiet space to rest. He comes to the ER today because this headache has persisted for the past 72 hours and they typically resolve within several hours to a couple of days. Temperature is 36.7 (98.7 F), Blood Pressure is 130/80, Heart Rate is 72 beats/minute. Neurological examination demonstrates normal alertness, cognition, and language; normal cranial nerve examination with normal optic discs (no papilledema); normal motor power, tone, and no tremor; normal sensory exam; normal muscle stretch reflexes; and normal gait. Cardiopulmonary auscultation is normal. What is the most appropriate next step in the evaluation of this patient?