Klumpke Palsy
Klumpke palsy may produce several abnormal postures. Classically, it produces flexion and supination of the elbow, extension of the wrist, hyperextension of the metacarpophalangeal joints, and flexion of the interphalangeal joints with the “claw hand” posture (Figure 220.1A). This presentation is rarely seen in the newborn period. Klumpke syndrome usually manifests in the newborn period as weakness restricted to or mainly involving the hand (Figure 220.1B). In many occasions, there are no reflex or spontaneous movements of the intrinsic hand muscles.

The most frequent sites of involvement are the lower trunk (Figure 220.2 [B]) or a combination of T1 roots and C8 ventral ramus (Figure 220.2 [A]).

Figure 220.2.— Site of injury in Klumpke palsy. [A] Root of T1 and spinal nerve of C8. [B] Lower trunk. The green lines at T1 represent the most frequent origin of sympathetic fibers for the eyes. (PS): paraspinal muscles; (R): rhomboid muscle; DS: dorsoscapular nerve; LT: long thoracic nerve; (SA): serratus anterior muscle; (SS): supraspinal muscle; (IS): infraspinal muscle; SPS: suprascapular nerve; PL: pectoral lateralis nerve; (P): pectoralis muscle; PM: pectoralis medialis nerve; SF: sympathetic fibers to the eyes; (M of M): muscle of Müller; (DP): dilator pupillary muscle; (TM): teres major muscle; (SBS): subscapularis muscle; SBS: subscapularis nerves; TD: thoracodorsal nerve; (LD): latissimus dorsi muscle; MC: musculocutaneous nerve; (Bi): biceps muscle; (Br): brachialis muscle; M: median nerve; U: ulnar nerve; A: axillary nerve; (TMi): teres minor muscle; (D): deltoid muscle; R: radial nerve.