Viva 3

A 53 year old man presents to the Emergency Department with a sudden onset of severe occipital headache followed by a generalised tonic clonic seizure. His GCS is now E3V2M2.

Initial observations: Temperature of 38.5°C PR 110/min

BP 220/135 mmHg 
SpO2 91% on 15L O2 by Hudson mask

He is previously well and is taking no current medications.

What is your differential diagnosis for this man’s presentation?

Disclaimer: the viva stem above may be an original CICM stem, acquired from their publicly available past papers. Or, perhaps it is a slightly altered version of the original CICM stem. Or, it is a completely original viva stem, concocted by the monstrously amoral author of Deranged Physiology for nothing more than his own personal amusement. In either case, because the college do not make the main viva text or marking criteria available, almost everything here has been confabulated. It might sound like a plausible viva and it could be used for the purpose of practice, but all should be aware that it does not represent the "true" canonical CICM viva station.