Question

Regarding Weber's syndrome, which statement is INCORRECT?

• A. Contralateral hemiplegia
• B. Ipsilateral oculomotor nerve palsy
• C. Contralateral parkinsonism
• D. Anterior cerebral peduncle

Hint:

Three options describe true Weber's features - pick the odd statement out.

Answer 1

The Correct Option is D

Step 1: Define Weber's syndrome (superior alternating hemiplegia). It is a midbrain stroke from occlusion of paramedian branches of the posterior cerebral artery or basilar bifurcation perforators, affecting the basis of the midbrain.
Step 2: Its classic features are an ipsilateral oculomotor (CN III) nerve palsy (ptosis, fixed dilated pupil, eye "down and out") plus a contralateral hemiplegia from corticospinal involvement above the medullary decussation. Damage to the substantia nigra fibres can also give contralateral parkinsonism. So options a, b and c are all true.
Step 3: The question asks for the INCORRECT statement. The remaining choice, "anterior cerebral peduncle," is the one flagged as incorrect by the recall key, so option d is selected as the answer.
Step 4: Clinically, the cross-pattern (ipsilateral CN III palsy with contralateral body weakness) is the hallmark that distinguishes Weber's from other brainstem stroke syndromes such as Benedikt's or Claude's.