Injuries to the brachial plexus are relatively common. hey are identiied in 1 to 3 per 1000 term births (Baskett, 2007; Lindqvist, 2012; Wall, 2014). In the study reported by Moczygemba and colleagues (2010), the incidence of brachial nerve injury was 1.5 per 1000 vaginal deliveries and 0.17 per 1000 cesarean deliveries. he incidence among 366,408 neonates born at Parkland Hospital was 3.5 per 1000 births (Wall, 2014). Breech delivery and shoulder dystocia are risks for this trauma. However, severe plexopathy may also occur without risk factors (Torki, 2012).
With plexopathy, the injury damages the nerve roots that supply the brachial plexus-C5_8 and T ,. With hemorrhage and edema, axonal function may be temporarily impaired, but the recovery chances are good. However, with avulsion, the prognosis is poor. In 90 percent of cases, damage to the C5-6 nerve roots causes Erb or Duchenne paraysis (Volpe, 1995). Injuries with breech delivery are normally of this type, whereas the more extensive lesions follow diicult cephalic deliveries (Ubachs, 1995). The C5-6 roots join to form the upper trunk of the plexus, and injury leads to paralysis of the deltoid, infraspinatus, and lexor muscles of the forearm. he afected arm is held straight and internally rotated, the elbow is extended, and the wrist and ingers lexed. Finger function usually is retained. Because lateral traction on the fetal head is frequently employed to efect delivery of the shoulders in normal vertex presentations, most cases of Erb paralysis follow deliveries that do not appear diicult.
Damage to the C8-T, roots supplying the lower plexus results in Klumpke paraysis, in which the hand is laccid. Total involvement of all brachial plexus nerve roots results in laccidity of the arm and hand, and with severe damage, there may also be Horner syndrome.
Because of its importance, the American College of Obstetricians and Gynecologists (2014a) convened a task force to review extant studies. his Task Force concluded that shoulder dystocia cannot be accurately predicted, but in most cases, axonal death does not occur and the prognosis is good. Lindqvist and associates (2012) reported complete recovery in 86 percent of children with C5-6 trauma, which was the most common injury, and in 38 percent of those with C5-7 damage. However, those with global C5-8-T, inj uries always had permanent disability. Associated clavicular fracture is somewhat protective (Wall, 2014). Surgical exploration and possible repair may improve function if there is persistent paralysis (Malessy, 2009).
FIGURE 33-4 Left facial nerve injury. This was almost completely resolved two days after delivery.