Klumpke's palsy involves deficits in which region?

Klumpke's palsy involves deficits in which region?

• A. Upper arm deficits
• B. Shoulder deficits
• C. Lower arm or hand deficits
• D. Elbow flexion deficits

Answer: (C)

Klumpke's palsy results from injury to the lower trunk of the brachial plexus, typically affecting the C8–T1 nerve roots. These roots feed the intrinsic hand muscles (the interossei, lumbricals, and the thenar/hypothenar groups) and some forearm flexors, so the deficit manifests in the hand and fingers—hence lower arm or hand deficits. Clinically this often produces weakness of finger movements and a loss of intrinsic hand function, sometimes with a characteristic clawing pattern of the hand and, in some cases, Horner's syndrome due to T1 involvement. Because the injury is distal to the shoulder and upper arm nerves, proximal functions like shoulder girdle movements and elbow flexion are typically preserved, which is why deficits in those regions point away from Klumpke's palsy.

Klumpke's palsy results from injury to the lower trunk of the brachial plexus, typically affecting the C8–T1 nerve roots. These roots feed the intrinsic hand muscles (the interossei, lumbricals, and the thenar/hypothenar groups) and some forearm flexors, so the deficit manifests in the hand and fingers—hence lower arm or hand deficits. Clinically this often produces weakness of finger movements and a loss of intrinsic hand function, sometimes with a characteristic clawing pattern of the hand and, in some cases, Horner's syndrome due to T1 involvement. Because the injury is distal to the shoulder and upper arm nerves, proximal functions like shoulder girdle movements and elbow flexion are typically preserved, which is why deficits in those regions point away from Klumpke's palsy.