A patient loses all conscious proprioception and discriminative touch from the right lower limb with preservation of pain/temperature. MRI shows a T2-bright lesion at T8 level right posterior column. Fibres carrying proprioception from the right lower limb travel in which fasciculus and on which side at C5 level?

• A Left fasciculus gracilis
• B Right fasciculus cuneatus
• C Right fasciculus gracilis ✓
• D Left fasciculus cuneatus

Explanation

Posterior column fibres (fasciculi gracilis and cuneatus) are ipsilateral throughout the spinal cord; they cross only in the medulla at the sensory decussation. Lower limb fibres travel in fasciculus gracilis (medial), upper limb in fasciculus cuneatus (lateral). Therefore, at C5 the right lower limb proprioception remains in the right fasciculus gracilis.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.