If he's in the neuro ICU it very likely means he has severe brain swelling and they need to aggressively control his intracranial pressure. Many causes of that be it a bleed, stroke, infection, inflammation, trauma and lots of zebras.
If you're playing the odds for his demographic, its statistically most likely to be an infectious/inflammatory cause - ie. meningitis.
Shades of that CP member in California who recently passed away
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