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Duchenne-Erb Palsy
The most
striking manifestation of Duchenne-Erb palsy is the abnormal posture of
the affected upper extremity when the neonate is moving the healthy arm
(Figure 216.1). This posture consists of adduction and internal rotation
of the shoulder, extension of the elbow, pronation of the forearm, and
flexion of the wrist and fingers.
There is minimal weakness of the extensors of the wrist and no finger
weakness.
Figure 216.1.— Typical posture of a neonate with Duchenne-Erb
palsy [A and B]. The posture consists of arm adduction and internal rotation,
extended elbow, forearm pronation, palmar flexion of the wrist, and good
finger movements. The presence of wrist flexion indicates minimal or no
involvement of C7.
Duchenne-Erb
palsy indicates involvement of C5 and C6 spinal segment fibers. The most
frequent site of involvement of these fibers is at the upper trunk prior
to the origin of the suprascapular nerve (Figure 216.2 B), but more proximal
damage can also occur (Figures 216.2 A). The clinical manifestations of
Duchenne-Erb palsy are so typical that it can not be confused with a lesion
at any other location.
Figure 216.2.—
Schematic representation of the brachial plexus and its nerves and muscles.
Site of injury. A: C5 root and C6 spinal nerve; B: upper trunk; (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.
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