Erb's palsy
From Wikipedia, the free encyclopedia
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| Brachial plexus | |
| ICD-10 | P14.0 |
| ICD-9 | 767.6 |
| DiseasesDB | 30827 |
Erb's Palsy, also known as Brachial Plexus Paralysis, is a condition which mainly due to birth trauma can affect 1 or all of the 5 primary nerves that supply the movement and feeling to an arm. The paralysis can be partial or complete; the damage to each nerve can range from bruising to tearing. Some babies recover on their own; however, some may require specialist intervention. A similar injury may be observed in adults following a traumatic fall on the side of the neck.
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[edit] Signs & Symptoms
Erb's Palsy is usually the result of delivery in shoulder dystocia. Shoulder dystocia is an obstetric emergency (1% of vaginal births) defined by the impaction of the baby's anterior shoulder against the mother's symphysis pubis. It is more common after an assisted vaginal delivery such as with forceps, ventouse cap etc to deliver the baby. The maneuvers used to deliver the baby may increase the head-shoulder interval, stretching the ventral nerve roots of the cervical spine. In some cases it causes avulsions. The most common avulsion is at Erb's point - an area in the antereolateral neck (roughly corresponding to the roots C5 + 6) which damages the nerve roots of the brachial plexus supplying the ipsilateral upper limb & shoulder girdle. In some cases the C7 nerve root is also affected. This injury impairs function of some or all of the following nerves and the muscle groups they supply:
- Axillary - Abduction, flexion, and extension of shoulder (deltoid, teres minor)
- Dorsal scapular - Retractors/Elevators of Scapula (rhomboids, levator scapulae)
- Suprascapular - Abduction of shoulder (supraspinatus) and lateral rotation of humerus (infraspinatus)
- Subscapular nerves - (subscapularis, teres major)
- Musculocutaneous - Flexion of elbow, pronation of arm (Brachialis, Coracobrachialis, Biceps Brachii)
- Long thoracic - Protraction of scapula (serratus anterior)
- Radial - Extensors of arm and forearm (triceps and many other muscles)
- Lateral pectoral - (pectoralis major)
This injury results in lost or impaired function of muscles of the rotator cuff, flexors of the elbow, and lateral rotators of the humerus. This manifests itself as a flaccid paralysis know as the Waiter's tip deformity, so named because the affected limb hangs at the side with the hand pointing backwards as in a waiter expecting a tip. This deformity is characterized by:
- Limb hangs loosely by side (Loss of shoulder function)
- Extension of elbow (loss of arm flexors)
- Pronated forearm (Biceps non-functional)
- Hand in pinch grip position
[edit] Treatment
Neonatal / pediatric neurosurgery is often required for avulsion repair. Lesions may heal over time and function return. Physiotherapy is often required to regain muscle usage.
Although range of motion is recovered in many children under one year in age, individuals who have not yet healed after this point will rarely gain full function in their arm and may develop arthritis.
[edit] Discovery
The renowned British obstetrician William Smellie is credited with the first medical description of an obstetric brachial plexus palsy. In his 1768 treatise on midwifery, he reported a case of transient bilateral arm paralysis in a newborn after difficult labour. In 1861, Guillaume Benjamin Amand Duchenne coined the term "obstetric palsy of the brachial plexus" after analyzing 4 infants with paralysis of identical muscles in the arm and shoulder. In 1875, Wilhelm Heinrich Erb concluded in his thesis on adult brachial plexus injuries that associated palsies of the deltoid, biceps and subscapularis are derived from a radicular lesion at the level of C5 and C6 rather than isolated peripheral nerve lesions.
[edit] Famous People
A famous person afflicted by Erb's palsy was Wilhelm II of Germany.
Also, Martin Sheen was injured during birth and developed the condition in his left arm. His difference in arm length and range of motion can be seen in his movies, especially Apocalypse Now.
