Preoperative Investigations in Obstetric Brachial Plexus Palsy

Treatment strategy in infants with obstetric brachial plexus palsy (OBPP) largely depends on clinical neurological examination and the degree of improvement in the first 3 months. Usually, less severe lesions show early recovery within a few months, and prognosis for spontaneous recovery is good. However, sometimes the time course of improvement may differ and will not allow clinical differentiation from more severe types of lesions with less favorable prognosis. Ancillary preoperative investigations assist in determining the type, level, and extent of the nerve lesion. The role of electrodiagnosis in preoperative assessment of OBPP is depreciated by many, whereas others stress the importance of combining results from electromyography and nerve action potential recording to discriminate between a nerve conduction block and a root avulsion or to predict the severity of axonal injury or degeneration. There is no role for motor-evoked potentials in OBPP yet. For imaging of the brachial plexus in infants, magnetic resonance imaging has surpassed computed tomography-myelography as modality of choice. High-strength magnetic resonance scanners, applying different techniques in a noninvasive way, allow imaging of plexus structures with great detail. Detection of different nerve lesion types is possible, such as root avulsions or nerve ruptures, formation of pseudomeningoceles, neuromas, or scarring as well as deformities of the shoulder joints. Magnetic resonance imaging is becoming a great aid as a preoperative investigation in determining treatment strategy in infants with severe OBPP. KEYWORDS Brachial plexus neuropathies - electrodiagnosis - diagnostic imaging