Erb’s Palsy; Causes, Symptoms, Diagnosis, Treatment

Erb’s palsy / Erb–Duchenne palsy is a form of obstetric brachial plexus palsy. It occurs when there’s an injury to the brachial plexus, specifically the upper brachial plexus at birth. The injury can either stretch, rupture or avulse the roots of the plexus from the spinal cord. It is the most common birth related neuropraxia (about 48%). .It is a paralysis of the arm caused by injury to the upper group of the arm’s main nerves, specifically the severing of the upper trunk C5–C6 nerves. These form part of the brachial plexus, comprising the ventral rami of spinal nerves C5–C8 and thoracic nerve T1. These injuries arise most commonly, but not exclusively, from shoulder dystocia during a difficult birth. Depending on the nature of the damage, the paralysis can either resolve on its own over a period of months, necessitate rehabilitative therapy, or require surgery.

Erb’s palsy[] is a condition where the upper part of brachial plexus (C5, C6) that innervates the arm is severed resulting in adducted, internally rotated shoulder and pronated forearm, typically known as “waiter’s tip” position. The most common cause being dystocia (associated with difficult breech and forceps deliveries), the nerve damage can vary from bruising to tearing and hence paralysis can be partial or complete. It is also caused by clavicle fracture unrelated to dystocia or following a traumatic fall at any age.[] The treatment of Erb’s palsy depends on the nature of damage, which is either nerve bruise or nerve tear. Nerve bruise usually resolve on its own over a period of months. However, in the latter case i.e. nerve tear, the following multiple approaches are advised physiotherapy[] for regaining muscle usage, surgical interference[] of nerve transplants (usually from the opposite leg), subscapularis releases, latissimus dorsi tendon transfers and rehabilitation therapy.

Erb's palsy

Another Name of Erb’s Palsy

Brachial plexus injury, Klumpke’s Palsy), Erb-Duchenne palsy, Radial Nerve Palsy, Shoulder Dystocia.

Erb’s Palsy

Erb’s palsy is caused by damage to the upper C5 and C6 nerves.  Children with Erb’s palsy have partial or full paralysis of the arm, possibly involving loss of sensation.  The affected arm hangs to the side, and cannot be fully raised.

Klumpke’s Palsy

Klumpke’s palsy involves paralysis of the forearm and hand muscles, caused by damage to the lower C8 and T1 nerves.  This primarily affects the wrist and fingers, and often appears as a “clawed” hand.

Anatomy of Erb’s PalsyErb's palsy

Neurologically, the Erb’s point is a site at the upper trunk of the Brachial Plexus located 2-3cm above the clavicle. It’s formed by the union of the C5 and C6 roots which later converge. Affected nerves in Erb’s palsy are the axillary nerve, musculocutaneous, & suprascapular nerve.

  • Axillary nerve– originates from the terminal branch of posterior cord receiving fibers from C5 and C6. It exits the axillary fossa
    posteriorly passing through the quadrangular space with posterior circumflex humeral artery. it fives rise to superior lateral brachial cutaneous nerve then winds around the surgical neck of the humerus deep to deltoid. It innervates the shoulder joint, teres minor and deltoid muscles, skin of superolateral arm.
  • Musculocutaneous nerve – originates from the terminal branch of lateral cord receiving fibers from C5-C7. It exits the axilla by piercing coracobrachialis, descends between biceps brachii and brachialis while supplying both, continues as lateral cutaneous nerve of forearm. It innervates the muscles of the anterior compartment of the arm and the skin of lateral aspect of the forearm.
  • Suprascapular nerve  originates from the superior trunk receiving fibers from C5, C6 often C4. It passes laterally across lateral cervical region superior to brachial plexus then through scapular notch inferior to superior transverse scapular ligament. It innervates the supraspinatus, infraspinatus and shoulder joint.

Types of Erb’s PalsyErb's palsy

Brachial plexus injuries are caused by nerve damage.  There are four types (listed in order of severity)

AvulsionThe avulsion is the most severe type of injury. The most severe type of nerve injury. An avulsion occurs when a nerve is totally torn from the spinal cord. It may be possible to repair an avulsion with surgery, where healthy nerves are spliced from another part of the body and replaced, but the affected nerve cannot be reattached to the spinal cord. It is a complete tearing of the nerve root from the spinal cord.  These types of tears are rarely treatable with surgery.

Neuropraxia/Stretch – Also known as “burners” or “stingers”, neuropraxia is the most common type of neural injury. This condition occurs when a nerve is stretched or “shocked” but does not tear. These injuries typically heal on their own within 3 months.

Neuroma  A more serious stretch injury that damages some of the nerve fibers. Neuroma can cause scar tissue to form as it heals, which presses on the remaining healthy nerve and creates discomfort. As a result, long-term recovery from neuroma is typically only partial, not complete.

Rupture  A stretch injury that occurs when the nerve itself is torn. Rupture injuries require surgery to splice and graft the nerve back together. This type of injury will not be able to heal on its own.

Narakas Classification
Group  Roots  Characteristics
Group I (Duchenne-Erb’s Palsy) C5-C6 Paralysis of deltoid and biceps. Intact wrist and digital flexion/extension.
Group II (Intermediate Paralysis)  C5-C7 Paralysis of deltoid, biceps, and wrist and digital extension. Intact wrist and digital flexion.
Group III (Total Brachial Plexus Palsy)  C5-T1 Flail extremity without Horner’s syndrome
Group IV (Total Brachial Plexus Palsy with Horner’s syndrome)  C5-T1 Flail extremity with Horner’s syndrome

Erb's palsy

Causes of Erb’s Palsy

  • Cephalo-Pelvic Disproportion – One of the causes for Erb’s palsy is due to cephalo-pelvic disproportion (CPD), a condition that occurs when the infant is proportionately too large for the birth canal. This is something that physicians are generally able to diagnose during the last few weeks of pregnancy.
  • Head-First Delivery – When an infant’s head gets stuck , the head pulls away from the shoulders, causing shoulder dystocia. Another scenario, however, and one that is more likely is that the baby’s head comes out of the cervix and the baby gets stuck. To aid with delivery, the doctor or nurses pull the baby out, thus causing an unnatural pull between the baby’s head and the shoulder.
  • Breech Delivery – When infants are in the breech position, an observant doctor will typically know weeks before delivery. Most physicians prefer to schedule a C-section so that there are no unnecessary risks and complications with the delivery.
  • Forceful Arm Pulling – Another possible cause of Erb’s palsy is when a physician pulls on the baby’s arms. It is rare that a baby would come out arms-first, so the pulling would then be committed after delivery, possibly from picking up a baby by his or her arms, causing unnatural stress.
  • C-Section – Although one of the most common reasons Erb’s palsy occurs is when a physician pulls and tugs an infant too hard during a regular delivery, in rare cases, the disorder can happen during a C-section.
  • Stretching – and stress during labor can occur if the baby is descending down the birth canal at an angle. In this case, the shoulders will not be directly behind the head, and one arm may be pulled in the opposite direction from the head.
  • If the baby is too large to pass easily through the birth canal (a circumstance referred to as cephalo-pelvic disproportion or CPD), the baby’s shoulders may experience excessive strain and pull, which can damage the brachial plexus nerves.
  • Breech babies are also at risk for developing Erb’s palsy, as the brachial plexus nerves can be damaged as the baby
  • Large infant size
  • Small maternal size
  • Excessive maternal weight gain
  • Second stage of labor lasting over an hour
  • Infants with high birth weight
  • Infants in the breech position

Symptoms of Erb’s Palsy

  • Weakness in one arm
  • Arm is bent at elbow and held against body
  • Decreased grip strength in hand of the affected side
  • Numbness in arm
  • Impaired circulatory, muscular and nervous development
  • Partial or total paralysis of the arm
  • Weakness in one arm;
  • Loss of sensation in the arm;
  • Partial or total paralysis of the arm;
  • Muscle weakness;
  • Inability to raise one’s arm or difficulty in doing so;
  • Arm flexed at the elbow and held firmly against the body;
  • Lack of movement in the upper or lower arm;
  • Lack of movement in the hand;
  • Decreased ability to grip.

Diagnosis of Erb’s Palsy

Differential Diagnosis

Erb palsy should be differentiated from other brachial plexus injuries such as Klumpke injury due to birth. In case of Klumpke injury, there is paralysis of the forearm and hand muscle due to injury in C7, C8, and T1.  The neonate presents with “claw hand” due to injury to the flexor muscles of the wrist, fingers, and forearm pronator. It also affects the intrinsic muscles. The neonate injury also may be associated with Horner syndrome due to the affection of T1 which will affect the dilators of iris and elevators of the eyelid.

On examination

  • The arm was internally rotated, adducted, elbow extended, forearm pronated and with a closed fist of right upper limb
  • Passive range of motion was not full and free at shoulder patient was crying on flexion and abduction beyond 150° and 130° respectively
  • Elbow, wrist, metacarpophalangeal joints and interphalangeal joints of right upper limb were full and free passively. There was no grasp reflex
  • All developmental milestones were normal, except for movements of right upper limb
  • Muscular contractions of the deltoid, biceps, triceps, supinator, flexor, and extensors of the wrist, metacarpophalangeal and interphalangeal were elicited suggestive of C5, C6, and C7 nerve damage[]
  • Muscle power was assessed for all the muscle groups of the right upper limb and was of grade 0.[]
  • MRI of the shoulder may demonstrate shoulder dislocation; the presence of pseudomeningoceles indicates avulsion injury of the affected spinal roots
  • CT Scan of the shoulder- may demonstrate shoulder dislocation; the presence of pseudomeningoceles indicates avulsion injury of the affected spinal roots

Treatment of Erb’s Palsy

Physiotherapy Management

During the first 6 months treatment is directed specifically at prevention of fixed deformities. Exercise therapy should be administered daily to maintain ROM and improve muscle strength. Parents must be taught to take an active role in maintaining ROM and keeping the functioning muscles fit. Exercises should include bimanual or bilateral motor planning activities.

  • Activities and exercises to promote recovery of movement and muscle strength
  • Exercises to maintain range of movement in the joints to prevent stiffness and pain
  • Sensory stimulation to promote increased awareness of the arm
  • Provision of splints to prevent secondary complications and maximise function
  • Educating parents on appropriate handling and positioning of the child and home exercises to maximise the child’s potential for recovery
  • Constraint induced movement therapy may be useful
  • Electrical Stimulation may be beneficial
  • Referral to Occupational Therapy for assessment of function in day to day activities
  • Gentle stretching exercises
  • Sensory stimulation
  • Range of motion exercises
  • Strength exercises

Occupational Therapy

Occupational therapy is often used in cases of Erb’s palsy that have not improved on their own after two to four months. Occupational therapy can help a child develop the strength to perform everyday activities, such as picking up a toy or bottle. An occupational therapist will use a range of movement exercises to improve joint function and muscle tone.

Ayurveda Treatment

  • Quantity sufficient of indirectly heated ABL Taila was applied in Anuloma Gati (downward) for 15 min
  • 25 g of Bala Mula (roots of Sida cordifolia Linn.) – was processed with 500 ml of Ksheera (milk) wherein milk was boiled to reduce the quantity to half and filtered. 25 g of Shastikashali was cooked very soft and made like paste with the above filtrate of Ksheera Yukta Bala Mula. This paste was applied with gentle circular movements for 20 min in Anuloma Gati. The patient was treated with a total of 35 days of Ayurvedic treatment, in three divided sessions [Tables  [Rx and  Rx].
  • Hydrotherapy – is a form of physical therapy used because of the anti-gravity environment. It minimized the stress on the musculoskeletal frame, allowing the neonate to move with less pain and at the same time strengthening muscles and reducing spasms. Paralyzed muscles relax in the opposite position of the waiter’s tip posture by abduction at the shoulder, external rotation of the arm, and supination of the forearm. Physiotherapy begins after two weeks. Surgical intervention, nerve graft, or nerve decompression is the next step if there is no response after 3 to 6 months.[Rx]

Surgery

In microsurgery, surgeons often use high-powered microscopes and small, specialized instruments. Nerve surgery does not typically restore full, normal function, and is usually not helpful for older infants.

  • Nerve graft. Depending upon the nerve injury, it may be possible to repair a rupture by “splicing” a donor nerve graft from another nerve of the child.
  • Nerve transfer. In some cases, it may be possible to restore some function in the arm by using a nerve from another muscle as a donor.

Release of contractures

  • Small maternal size
  • Indicated for patients w/ internal rotation & adduction contraction
  • Chronic internal rotation contracture leads to secondary osseous changes (increased glenoid retroversion) and posterior subluxation of the shouder
  • Early operative management includes – release of subscapularis (and in some severe cases release of the anterior joint capsule and pectoralis major)
  • Soft tissue release is performed inorder to regain external rotation and to prevent pathologic osseous changes;
  • It is important to note that aggressive anterior releases may result in anterior instability
  • some authors feel that the pectoralis does not usually result in contracture and does not require release;

Technique of release of subscapularis from the scapula

  • Sensory stimulation
  • As compared to releasing the subscapularis off of the humerus, this technique avoids anterior instability;
  • The patient is placed in the lateral position;
  • Make a longitudinal incision along the lateral border of the scapula;
  • identify the fibers of the latissimus muscle (over the lateral aspect of the scapula), and retract it inferiorly
  • The subscapularis is elevated off of the anterior surface of the scapula;
  • Increase in external rotation demonstrates the adequacy of the release
  • Avoid injury to the subscapular artery and nerve at the scapular notch and at the anteromedial aspect of the glenoid neck;
  • The splint is applied to maintain the arm in abduction and external rotation for 3 months, followed by 3 months of night splinting;

Tendon transfers

  • Sensory stimulation
  • indicated to counteract the shoulder adductors and internal rotator
  • generally performed prior to age 7 yrs;
  • latissimus dorsi may be transfered to the rotator cuff / greater tuberosity (augments external rotation power)
  • in the report by Edwards TB, et al, a retrospective study of the results of latissimus dorsi and teres major transfer in the treatment of Erb’s
  • palsy was conducted in 10 patients;
  • all patients underwent release of the pectoralis major and transfer of the latissimus dorsi and teres major tendons to the rotator cuff muscle
  • at a mean age of 7 years and 2 month
  • active shoulder abduction improved from a mean of 72 degrees preoperatively to 136 degrees postoperatively
  • postoperative shoulder active external rotation averaged 64 degrees
  • all but one patient were satisfied with the final outcome;

Posterior glenohumeral subluxation

  • Sensory stimulation
  • as w/ DDH, aggressive treatment early on may reverse the deformity, where as older children may require derotational osteotomy
  • limitation of external rotation;
  • for older children (older than 5 yrs of age) with fixed bony adaptive changes, proximal humeral external rotation osteotomy can be considered;
  • in late cases, w/ a deficient posterior glenoid consider humeral derotational osteotomy;

Forearm pronation deformity

  • correction of the supination deformity requires early intervention;
  • consider brachioradialis transfer through the interosseous membrane;

Prevention of Erb’s Palsy

Although not all birth injuries can be prevented, there are certain steps that can be taken in order to minimize the risks associated with developing Erb’s palsy. As a preventative measure, mothers can:

  • Seek regular prenatal care – This includes having your blood sugar monitored as well as the other risk factors associated with Erb’s palsy;
  • Take prenatal vitamins – Follow a healthy diet, take your doctor-recommended supplements and remain as active as your doctor suggests during your pregnancy;
  • Consider having a c-section – If it’s suspected that your child is overly large, he or she may be at risk for being lodged in the birth canal;
  • Plan ahead – Make sure to receive education about the risks associated with labor and delivery and be prepared to make decisions if emergent situations arise;
  • Ask the nurse, midwife or doctor questions – Inquire about how they address situations such as macrosomia and other birth complications;
  • Be sure physicians and other medical personnel keep you in the loop at all times, no exceptions – It’s helpful to remain informed at every stage of your pregnancy, labor and delivery. You deserve to be kept informed.

References

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