| Abstract: |
Brachial plexus birth palsy has an incidence of 0.38 to1.56 per 1000 live birth. The difference in incidence may depend on the type of obstetric care and the average birth weight of infants in different geographic regions. Perinatal risk factors include macrosomnia, multiparous pregnancies, prolonged labor, breech delivery, and assisted (vacuum or forceps) and difficult deliveries. Delivery by cesarean section does not exclude the possibility of birth trauma. Most commonly, a brachial plexus birth palsy involves the upper trunk (C5-C6) -the classic Erb’s palsy-, potentially in combination with an injury to C7, less often, the entire plexus (C5-T1) is injured. On extremely rare occasions the lower trunk (C8-T1) - klumpke’s paralysis- can be most significantly involved. Most infants with brachial plexus birth palsy recover within the first few weeks of life with no functional deficit, some are lift with persistent paresis of the upper extremity including shoulder, elbow, and the hand. Treatment of brachial plexus injury is primary- nerve grafting, nerve transfer- or secondary surgery including contracture release, muscle transfer, osteotomies, or arthorodersis.Brachial plexus injury lead to muscular and periarticulat tightness, failure of neuromuscular recovery which can produce several deformities including; adduction internal rotation deformity with or without joint deformities- due to external rotator weakness-, external rotation deformity-infraspinatus and teres minor contracture-, pure abduction, winging of the scapula, or flail joint.Invasive radiographic studies with myelography, combined myelography and computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans have been used to diagnose brachial plexus injuries and to distinguish between avulsion and extraforminal rupture. Myelography had an 84% true-positive rate with 4% false–positive and 12% false-negative rates. The addition of CT with myelography increase true positive rate to (94%). MRI had a true-positive rate similar to that of myelo-CT studies, but also allow extraforaminal evaluation of the plexus. High spino-echo MRI increase resolution of MRI analysis. Electrodiagnostic studies with electromyography (EMG), sensory nerve action potentials (SNAP), and somatosensory evoked potentials (SSEP) have also been used in an attempt to improve the diagnostic accuracy of the severity of the neural lesion.There are many methods which can used to evaluate the deformities, including:- Assessment of the motor function by different scoring system.- X-ray for bone and joints.- Computed tomography for children older than 5 years.- Magnetic resonance imaging for children younger than 5 years.- Arthroghraphy.- Ultrasound.- Arthroscopy, in shoulder affection.The role and timing of microsurgery are the most controversial issues in the care of these infants. The spectrum of nerve surgery includes neurolysis, neuroma resection, nerve grafting, and nerve transfers.Shoulder problems are the most common sequel of brachial plexus injury, and treated surgically according the deformity. Cases of inernal rotation adduction contracture without joint deformity treated by muscle contracture release or muscle transfer, and if there is joint deformity the treatment is by external rotation osteotomy of the humerus. Cases of external rotation contracture treated by lengthening of the contracted posterior muscle of the shoulder, and if there is joint deformity the treatment is by internal rotation osteotomy of the humerus. Cases of weak abduction treated by muscle transfer to replace some portion of the function of paralyzed deltoid. Scapular winging treated by static stabilization, fusion on the thoracic wall, or muscle transfer.Secondary surgery in elbow problems is muscle transfer to augment extension or flexion weakness.The wrist and hand are the most difficult part of reconstruction in complete paralysis this due to limited number of muscle able to transfer. Secondary surgery including; muscle transfer, nerve transfer, muscle transplantation, tenodesis, or wrist arthropdesis. The severity of hand problems justify an attempt to reinnervate the lower roots of the brachial plexus during plexus repairs.Conclusion:Brachial plexus birth palsy is a common injury. Most cases recover spontaneously. Brachial plexus injury evaluated clinically and by different imaging studies. The role and timing of microsurgery is the most controversial issues of these children, its major complication is the failure to achieved the desired outcome. Children with chronic plexopathy must have secondary surgery. There is continuous clinical development in the care of these children either in the surgical treatment- microsurgery or secondary surgery-, or in the different evaluation methods.
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