A 22 year old man presents with a recurrent, severe headache in the left periorbital region for 5 months, which occurred between 5 to 10 times each day.
The episodes were abrupt in onset, lasted between 30 minutes to 2 hours, and were accompanied by lacrimation and rhinorrhea.
There was no aura or any obvious precipitating factors. His medical and surgical histories are unremarkable.
He had self-medicated himself with acetaminophen (paracetamol) and ibuprofen so far.