BRACHIAL PLEXUS INJURY IN NEONATES

LOURDES ASIAINFebruary 2005

1764 Obstetrical brachial palsy described by Smellie.

1874 Wilhelm H. Erb described brachial plexus paralysis in adults which involved the upper roots and described certain types of “delivery paralysis”. He credited Duchenne for describing the brachial palsy following delivery in affected newborns.

1885 Augusta Klumpke first described the clinical picture resulting from injury to lower roots.

BACKGROUND

EPIDEMIOLOGY

Incidence of brachial plexus palsy is reported to affect 0.5 to 1.9 per 1000 live births (Bar et al 2001)

90% Erb palsy

Most common on the right side because the most commondelivery presentation is left occiput anterior vertex.

Associated with: pre and gestational diabetesolder maternal ageincreased BW, LGA

Newborns with BP injuries have a higher incidence of low Apgar scores of less than 7 at 1 and 5 mins and of asphyxiathan matched controls

Brachial plexus palsy occurs in 26% of cases of shoulderDystocia

Both Shoulder dystocia and brachial plexus palsy are morecommon in LGA babies and Infants of diabetic mothers

Infants of diabetic mothers have a higher incidence of permanent impairment

In infants of diabetic mothers, the macrosomic process affects the trunk but not the head (large biacromial diameter)The head shoulder disproportion is difficult to predict inUtero.

EPIDEMIOLOGY

Clavicular fractures are often associated with shoulderdystocia , but the incidence of brachial palsy in theseCases is only 11%.

Clavicular fracture =more mobility of shoulder

Not always associated with difficult delivery (IntrauterineMaladaption palsy). Cases of in utero origin supported by EMG findings if denervation at birth.

EPIDEMIOLOGY

ANATOMY

ANATOMY

Brachial plexus is comprised of a group of nerves arising form the nerve roots C5-T1.

The uppper (C5-C6) roots innervate the deltoid, spinati,biceps,brachioradialis, biceps supinator and flexor muscles ofthe forearm.

The lower roots (C7-T1) innervate the intrinsic musclesof the hand.

The phrenic nerve, arising from C3-C5 can be involved resulting in ipsilateral diaphragmatic paralysis causing adecrease in thoracic space, tidal volume and vital capacity.

Involvement of the sympathetic nerves from T1 that give riseto the sup cervical symp ganglion can result in Horner Synd.

HORNER SYNDROME

PtosisMiosis and anhydrosis

Stretch, tear, compression or avulsion of the nerves

usually after forceful lateral deviation of the head from the shoulders during delivery. Recent studiessuggest intrinsic forces(uterine contractions).PATHOGENESIS

Clinical Manifestations:

Asymmetric Moro reflex

Erb palsy caused by the disruption of the upper brachial plexus. Posture of adduction and inward rotation at the shoulder with extension and pronation at the elbow and flexion of the fingers = WAITER’S TIP

Klumpke= absent grasp reflexof the hand

Clinical Manifestations

If phrenic nerve is involved, as mentioned earlierrespiratory distress may be present.

DIFFERENTIAL DIAGNOSIS

Cervical Injury

Cervical Spine injury

Dislocation of upper extremity/fractures of upper extremity

Intrauterine maladaptation palsy

The physical findings of BP palsy are so unique so it is difficult to mistaken if for other diagnosis.

DIAGNOSTIC WORKUP

Evaluation can be undertaken by multiple modes of Imaging.

EMG

MRI

Chest X ray

Real time UltraSonography

MANAGEMENT

The majority of patients with brachial plexus palsy Dx at birth will recover from neurologic deficit.Those who do not recover during 3-6month period willRequire surgical intervention.

1-2 week rest of affected limb

Early referral to upper extremity clinic and PT

Caregivers should be instructed on how to handle baby:No traction of affected arm, no pressure under axila. Baby to be carried in football hold

MANAGEMENTSurgical•Exploration

•Neurolysis•Excision of scar tissue•Nerve grafting (local end to end anastomosis or remote

nerve transplant)

•Surgical plication in case of diaphragmatic involvement

Special considerations in post surgical care:Edema of neck and compromise of airwayInjury to vagal and laryngeal nervesRisk for meningitis

PROGNOSISStudy by Noetzel et al (2001) followed 80 patients with BP injury who did not recover by 2 weeks of age.

Used the BMRC scales for evaluating muscle strength and found:

Complete recovery in 66%Mild impairment in 11%Moderate weakness was seen in 9%Severe weakness in 14%

When associated with phrenic nerve palsy and diaphragmatic paralysis, there is more likelihood of need for surgery for recovery.

REFERENCES

Brachial plexus palsy in neonates John B Cahil, Medlink

Brachial plexus injury and obstetrical risk factors. Int J Gynecol Obst 2001;73 (1) 21-5

Brachial plexus injuries, emedicine Aug 2004

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