The functional outcome with conservative management of 186 patients with obstetrical brachial plexus palsy, evaluated between 1981 and 1993, is reviewed at the Children’s National Medical Center, George Washington University, Washington, DC. The majority (88%) had impairment ratings of mild (63%) to moderate (25%); 12% had complete lesions involving C4-5 to T1 and were rated severe. The palsy was bilateral in 7 patients. Perinatal complications included fractures of the clavicle (8) and humerus (5), Horner’s syndrome (8), respiratory distress (16), transient stridor with recurrent laryngeal nerve involvement (3), phrenic nerve palsy (3), and torticollis (11). Of 10 with complete lesions, 5 had MRIs of cervical spines, and all showed root avulsions. The initial (at <3 months) clinical impairment ratings correlated closely with those at the last follow-up exam and with the electrodiagnostic studies repeated at intervals. Only 6 (4%) of 149 patients showed complete recovery, and 92 (62%) had mild impairments, including winging of the scapula, restricted shoulder abduction and external rotation, forearm supination, but normal hand use and sensation. The original severity groups were unchanged at follow-up in 108 (72%) patients. In 41 (28%) patients with discrepant scores at follow-up, 31 had improved by one grade, 2 improved by 2 grades, and 8 deteriorated between the first and last exam. Of 46 patients with typical Erb’s palsy, graded as moderate in severity at initial exam, 28 had persistent functional limitations at follow-up. Selection criteria for microsurgery in this population were not clearly defined. [1]

COMMENT. The majority of patients with obstetrical brachial plexus palsies have mild to moderate upper plexus lesions. In this study, complete recovery was exceptional, and mild sequelae were the rule.

Alfonso I et al, Miami Children’s Hospital, review the differential diagnosis and management of obstetric brachial plexus injury [2]. Prenatal non-obstetric trauma produces a fixed anatomical deformity and EMG fibrillations present at or soon after birth. These authors recommend early EMG only in the exceptional cases without history of a difficult birth, those infants with a low birth weight, and with signs of congenital muscular atrophy or contractures indicative of prenatal pathology. Congenital chicken pox, amniotic bands, and pseudoparalysis due to fractures or osteomyelitis may mimic Erb’s palsy. I have seen cases of congenital syphilitic osteochondritis that presented as pseudoparalysis and were treated initially as an obstetric Erb’s palsy.

Caution is required in the interpretation of fibrillation potentials in the newborn infant. Transient spontaneous potentials, similar in amplitude, duration, and frequency to fibrillation potentials, have been reported in “essentially normal” premature and full-term infants. Jones HR, Bolton CF, Harper CM [3] have reviewed in detail the electromyography of newborns and reasons for inconclusive or erroneous EMG clinical correlations. Animal data suggest that fibrillation potentials may occur within 2 days after nerve section. EMG must be performed during the first 12 to 48 hours of life in order to attempt a distinction between prenatal and perinatal nerve injury. Further studies are needed to determine more accurately the temporal relationship of injury to onset of denervation potentials in the newborn. It might be imprudent to rely on EMG findings alone to assign cause of brachial plexus injury in obstetric litigation cases.