On MRI of the brain, a hypointense signal on T1 and hyperintense on T2 is seen in the posterior limb of the right internal capsule. This lesion is MOST likely causing which finding?

• A Right-sided pure motor hemiplegia
• B Left-sided hemisensory loss only
• C Left-sided pure motor hemiplegia ✓
• D Left-sided homonymous hemianopia

Explanation

The posterior limb of the internal capsule carries corticospinal and corticobulbar fibers from the motor cortex to the spinal cord; these fibers decussate in the medullary pyramid. A right posterior limb lesion interrupts the right corticospinal tract, producing contralateral (left-sided) pure motor hemiplegia — the lacunar syndrome known as pure motor stroke. Sensory loss would involve the genu or posterior thalamus. Homonymous hemianopia arises from optic radiation injury in the retrolenticular internal capsule.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.