Author: Amy Knowles / Editor: Nick Tilbury / Codes: OptC1, OptP3, OptP4, SLO1Published: 28/01/2021

A 26-year-old woman presents to the ED with a 3-hour history of what she describes as “the worst hangover of my entire life”. Her symptoms are a severe left sided frontal headache. She is persistently vomiting in the ED and asks if she can lie down in a dark room whilst she waits for assessment.

She presents following a binge on alcohol and MDMA. She also admits to smoking cannabis a few hours before her symptoms started. She has a past medical history of migraines.

On examination she is vomiting profusely. She is pale, sweaty and extremely distressed. She is GCS 15/15 and her observations are all within normal limits.

You proceed to a neurology examination and are surprised to find the patient’s left pupil is 6mm and does not react to light, her right pupil is normal. Her visual acuity is right eye 6/9, left eye 6/18. The sclera of her left eye is much redder than her right. There are no other abnormalities with her examination.