13th February 2025

A 50-year old man presents to A&E with a 1-day history of headache and diplopia.

A 50-year old man presents to A&E with a 1-day history of headache and diplopia. He is having difficulty reading the newspaper and watching television. He has unequal pupils (left 2 mm and reactive, right 4 mm and unreactive) and a droopy right eyelid. What is the most important initial investigation?

Select the SINGLE most appropriate option from the list below. Select ONE option only.