A 62-year-old diabetic woman presents with sudden numbness involving the entire right side of the body, face, arm, and leg equally. There is no weakness, no cortical deficit, and no speech disturbance. MRI shows a small deep infarct. Which arterial territory is involved?

• A Lenticulostriate branches supplying the internal capsule
• B Paramedian branches of the basilar artery
• C Cortical branch of the middle cerebral artery
• D Thalamogeniculate branch of the posterior cerebral artery ✓

Explanation

Pure sensory stroke localises to the ventral posterolateral and ventral posteromedial nuclei of the thalamus, supplied by thalamogeniculate branches of the posterior cerebral artery. Face, arm, and leg are affected equally because somatotopic representation converges in the thalamus. A lenticulostriate lacune typically causes pure motor hemiparesis, while a cortical MCA infarct would produce additional cortical signs such as aphasia or neglect, both absent here.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.