Erb’s Palsy in a Newborn Child and Clinicoanatomical Approach

Debajani Deka

doi:10.11648/j.bs.20210701.13

Abstract

Erb’s palsy is found in upper trunk of brachial plexus. C5, C6 roots join to from upper trunk. Each trunk again divides into anterior and posterior divisions. All trunks and divisions are found above the clavicle in the posterior triangle of neck. Branches from the upper trunk are suprascapular nerve and nerve to subclavius. Suprascapular nerve supplies supraspinatus and infraspinatus muscle along with it a articular trig to capsule of shoulder joint. Supraspinatus helps in initial 15 ºabduction at shoulder joint. Infraspinatus acts as lateral rotator of shoulder joint and assists subscapularis and teres minor muscles to abduct at this joint when there is contraction of middle fibers of deltoid and supraspinatus. Some fibers of C5 also give contribution to accessory phrenic nerve. Lateral cord of brachial plexus giving– musculocutaneous nerve, lateral pectoral nerve, lateral root of median nerve. Musculocutaneous nerve supplies all flexor muscles of arm like biceps brachii, brachialis, coracobrachialis. Brachialis muscle flexes the elbow joint, coracobrachialis is a weak flexor of shoulder joint and biceps brachii is a strong supinator of forearm, flexor of elbow joint only when forearm is supinated. Injury occurs in the Erb’s point found in the upper trunk of brachial plexus where there are emergence of six branches- C5 & C6 nerve roots, suprascapular nerve, nerve to subclavius, anterior and posterior division of upper trunk of the plexus. In this palsy, the arm remains medially rotated and adducted at the shoulder joint, the elbow is extended or semiflexed, forearm is pronated, and the wrist semiﬂexed. In this case a newborn child was found unable to flex his elbow, and abducted the arm on the right side. The limb is medially rotated, adducted in shoulder joint, semiflexion at the elbow joint and forearm pronated and wrist semiflexed. The child was kept on artificial respiratory ventilation. Plain Chest X-ray done to see if any musculoskeletal abnormality is there but no positive findings found so far. Both the clavicles and all ribs were found intact. Both domes of diaphragm were moving normally. On the other hand left sided upper limb found fully flexed at the elbow joint, supinated at forearm, abducted externally rotated at the shoulder joint and wrist extended. Moros reflex on the right side was absent but on left side it was clearly present. So, there is asymmetrical Moros reflex.

Highlights

Wilhelm Heinrich Erb is a eminent German neurologist
Neuropraxia is nerve compression injury which is reversible, axonometric injury is disruption of axon & myelin sheath which takes months to heal with proper treatment and physiotherapy whereas neurometric injury is irreversible where there is avulsion of roots, axons and myelin sheath along with structures enervated by these nerves
[5] Ernst Moro in 1918 first coined the term Moro Reflex. This reflex is a primitive reflex seen in neonate immediately after birth being seen in some preterm infants at 25 weeks of Postconceptional age (PCA) and in the majority by 30 weeks of PCA

Summary

Introduction

Wilhelm Heinrich Erb is a eminent German neurologist. In 1883 he published his text “Electrotherapeutics’ where he mentioned that there is a circumscribed point midway between mastoid process and midclavicle called ‘Erb’s point’ along the posterior border of sternocleidomastoid muscle. The term Erbs point is derived from his name He tried experiments on contractions of arm muscles by giving transcutaneous electrical stimulations. (2) Extended Erb's palsy involves C5, C6, C7 nerve roots and wrist drop is seen; the new born presents with the “waiter's tip posture” where the shoulder is adducted, arm is internally rotated, the elbow is extended, and the wrist is flexed i.e. wrist drop. (3) Total palsy, all roots of the brachial plexus are involved C5, C6, C7, C8 as well as T1 All these injuries neonate suffers from severe traction on neck. [15] Left anterior occipitoiliac presentation leads to excessive traction on right neck during vaginal delivery as right shoulder remains under the pubis Because of this this type of injury is most prevalent on right side. In 4% of cases injury can be bilateral. [16] Nerve repair in brachial plexus injury involves resection of neuroma or nerve grafting usually by sural nerve where damaged section of nerve is rejected and nerve graft is placed connecting the proximal and distal ends of the rejected nerve. [17]

Case Report

Discussion

Conclusion