The nerve supply to the arm is from nerve roots C5-T1 via the brachial plexus. The nerves pass under the clavicle and end in the axilla.1

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Adults
Signs and symptoms
Traumatic injury mostly occurs in severe road traffic accidents (especially on a motorcycle) and falls from heights. Young men are most commonly affected. The position of the arm (as the injury occurs) will determine the levels involved.
If the arm was held at the side, a C8-T1 injury is usual. However, if the arm is abducted, C7 is commonly involved.
Symptoms are often associated with:
- Broken clavicle.
- Swelling around the shoulder.
- Neck and shoulder pain.
- Paraesthesiae and weakness in the arm.
- Horner's syndrome, which indicates complete lesion in the lower plexus, i.e. C5-C7.
Examination
Sensory nerves:
Pinch the nail base, pull the finger outwards and ask about feeling anything. A burning feeling indicates continuity in the following nerves; absence does not necessarily mean nerve is divided but may be due to neurapraxia instead.
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Examination can be made difficult by anomalous nerve distribution, including C4 contributing to the brachial plexus and also because many muscles are supplied by more than one motor neuron. Assessment of loss of motor function at the cervical root:
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Neonates
Many cases are temporary, with full function recovering within one week. Permanent injury is found in up to 25%.2
- There are two types of brachial plexus paralysis in neonates: the upper plexus injury is called Erb's palsy; the lower plexus injury is called Klumpke's palsy.
- In the UK the incidence is 0.42 per 1,000 live births.3
- They can occur when the head is pulled away from the shoulder during delivery. A small proportion is unrelated to delivery.4
Risk factors
- Large birthweight and/or maternal diabetes.
- Shoulder dystocia (increases the risk for brachial plexus injury 100-fold).
- Breech presentation.
- Multiparity.
- Second stage of labour lasting more than 60 minutes.
- Assisted delivery.
- Intrauterine torticollis.
Examination
Examine 48 hours after delivery for a more reliable assessment.
- Erb's palsy (C5-C6 injury) - the arm is characteristically held adducted and internally rotated with the forearm pronated, hand and wrist flexed ('waiter's tip' position). The infant is unable to move the arm or shoulder.
- Klumpke's palsy - Horner's syndrome is present, i.e. meiosis, ptosis, anhydrosis.
Investigations
- High-resolution MRI requires no radiation exposure, is non-invasive, and provides more detail than CT myelography.
- Plain X-rays can be useful to diagnose hemidiaphragm paralysis from phrenic nerve involvement, or fractures of the clavicle or humerus.
- Electromyography.
- Nerve conduction studies.
Management
General measures
- Adult trauma: physiotherapy with possible bracing to prevent contractures.
- Neonatal: spontaneous recovery usually occurs and can start within days but can take months:
- Physiotherapy can help.5
- Other treatments include botulinum toxin injection and electrical stimulation.6
- Neuromuscular electrical stimulation (NMES) is a treatment used in an older child, where muscles are stimulated by pulsating alternating currents. It should be titrated with guidance from the child to allow muscle contraction without pain.
- Prevention of obstetric injury is not always possible, as a significant proportion of injuries may occur in utero.7
Surgical
Complications
- Progressive contractures.
- Deafferentation pain; this occurs when the nerve roots are avulsed in preganglionic lesions. The cells in the dorsal column are robbed of their nerve supply. After the injury (days to weeks), spontaneous signals are generated by these cells, which result in intractable pain for the patient.
- Bony deformities.
- Scoliosis.
- Posterior shoulder dislocation.
- Agnosia of the affected limb.
Document references
- Leinberry CF, Wehbe MA; Brachial plexus anatomy. Hand Clin. 2004 Feb;20(1):1-5. [abstract]
- Semel-Concepcion J et al, Neonatal Brachial Plexus Palsies, Medscape, Jan 2009
- Doumouchtsis SK, Arulkumaran S; Are all brachial plexus injuries caused by shoulder dystocia? Obstet Gynecol Surv. 2009 Sep;64(9):615-23. [abstract]
- Allen RH, Gurewitsch ED; Temporary Erb-Duchenne palsy without shoulder dystocia or traction to the fetal head. Obstet Gynecol. 2005 May;105(5 Pt 2):1210-2. [abstract]
- DiTaranto P, Campagna L, Price AE, et al; Outcome following nonoperative treatment of brachial plexus birth injuries. J Child Neurol. 2004 Feb;19(2):87-90. [abstract]
- Ramachandran M, Eastwood DM; Botulinum toxin and its orthopaedic applications. J Bone Joint Surg Br. 2006 Aug;88(8):981-7.
- Doumouchtsis SK, Arulkumaran S; Is it possible to reduce obstetrical brachial plexus palsy by optimal management Ann N Y Acad Sci. 2010 Sep;1205:135-43. doi: 10.1111/j.1749-6632.2010.05655.x. [abstract]
- Hale HB, Bae DS, Waters PM; Current concepts in the management of brachial plexus birth palsy. J Hand Surg Am. 2010 Feb;35(2):322-31. [abstract]
- Terzis JK, Kokkalis ZT; Outcomes of hand reconstruction in obstetric brachial plexus palsy. Plast Reconstr Surg. 2008 Aug;122(2):516-26. [abstract]
Internet and further reading
- Foster MR, Traumatic Brachial Plexus Injuries, Medscape, Jul 2011
- Orebaugh SL, Williams BA; Brachial plexus anatomy: normal and variant. ScientificWorldJournal. 2009 Apr 28;9:300-12. [abstract]
| Original Author: Dr Hayley Willacy Last Checked: 3 Dec 2011 | Current Version: Dr Hayley Willacy Document ID: 1882 Version: 22 | Peer Reviewer: Dr Helen Huins © EMIS 2011 |