Which syndrome corresponds to Weber's description of ventral midbrain lesion with contralateral hemiparesis and ipsilateral CN III palsy?

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Weber's syndrome arises from a ventral midbrain lesion that hits two key pathways: the oculomotor nerve fibers as they course through the cerebral peduncle and the corticospinal tract in the crus cerebri. When the paramedian branches of the posterior cerebral artery infarct this area, you get ipsilateral oculomotor palsy (drooping eyelid, "down and out" eye, and possibly a dilated pupil) along with contralateral spastic hemiparesis from the corticospinal tract interruption. The classic combination—opposite-side weakness with same-side third nerve palsy—defines Weber's syndrome. Other midbrain syndromes involve different structures (for example, Benedikt’s adds tremor from red nucleus involvement, Claude’s adds ataxia from dorsal midbrain involvement), which helps distinguish them.