[Ramachandran]

What? Ipsilateral dilated pupils
Why? CN III compression

What? Contralateral homonymous hemianopsia
Why? Posterior cerebral artery compression

What? Ipsilateral paresis
Why? Compression of contralateral crus cerebri [Kernohan's notch], this is a false localizing sign

What? Duret hemorrhage of pons and midbrain
Why? paramedian artery rupture because of caudal displacement of the brain stem