Erb's Palsy

Erb-Duchenne paralysis

Erb's palsy is caused by damage to the brachial plexus during delivery of the neonate. This is mostly limited to the Vth and VIth cervical nerves.

• Rare; in the United States the incidence has ben quoted as 1.6-2.9 per 1000 live births¹
• Upper plexus palsies are more common than lower plexus palsies
• 50% of cases are associated with shoulder dystocia

Infant is unable to

1. abduct the arm from the shoulder
2. rotate the arm externally from the shoulder
3. supinate the forearm

This results in the classic "porter's tip" or "waiters tip" appearance¹

Clinical signs

• Characteristic position - adduction and internal rotation of the arm with forearm pronated
• Forearm extension normal
• Biceps reflex absent
• Moro reflex absent on affected side
• Sensory impairment on outer aspect of arm (unusual)
• Power of the forearm is normal (if impaired suggests injury to lower part of plexus)
• Hand grasp normal unless lower part of plexus is also damaged

• MRI shows nerve root damage
• EMG and nerve root studies are not helpful in determining the extent of the damage severity,¹ although this has been opposed.²

• Intermittent immobilisation and positioning to prevent contractures
• Positioning such that arm is abducted to 90 degrees, externally rotated at the shoulder, supination of forearm, extension at wrist with the palm turned toward the face
• Gentle massage
• Physiotherapy with active and passive movement exercises by end of first week
• Referral to neurosurgeon if paralysis persists beyond 3 months or more proximal damage to plexus¹
• Surgery can involve direct neurorrhaphy after neuroma resection - however results are mixed and pain along with functional disability persist in significant numbers²

• Depends upon degree of damage
• Effective hand grasp throughout is associated with a good prognosis
• Function may return within a few months
• Some may have be left with permanent damage

Named after Wilhelm Heinrich Erb (1840-1921) a german neurologist who described a case in 1874 although an earlier case was described by Duchenne in 1872. However Erb was also a pioneer in a description of the electrophysiologic nature of tetany, characterisation the physiologic response to stimulation of the superior root of the brachial plexus, and describing the deep tendon reflex.⁴