A 28-year-old man involved in a motorcycle crash has weakness of the intrinsic muscles of the left hand with a claw deformity and sensory loss along the medial forearm. He also has an ipsilateral ptosis and miosis. The combination suggests avulsion of which roots?
- A C5 and C6
- B C6 and C7
- C C8 and T1 ✓
- D C7 and C8
Correct answer: C. C8 and T1
Explanation
Klumpke's palsy results from lower trunk (D8, T1) traction or avulsion, producing intrinsic hand weakness, a claw hand and medial forearm sensory loss. The preganglionic T1 fibres carry sympathetic outflow to the head, so their avulsion causes ipsilateral Horner syndrome (ptosis, miosis, anhidrosis). This association makes Horner syndrome a marker of preganglionic lower trunk injury and a poorer prognosis for spontaneous recovery.
Reference: Gray's Anatomy for Students, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.