Evidence of Lumbosacral Plexus Involvement on MR Neurography in Early Guillain-Barré Syndrome (P14-8.015)

Abstract

<h3>Objective:</h3> To describe a case of early Guillain-Barré Syndrome (GBS) with novel findings of lumbosacral plexus involvement on MR neurography. <h3>Background:</h3> GBS is an acute inflammatory polyradiculoneuropathy characterized by progressive sensory loss, weakness, areflexia, CSF albumino-cytologic dissociation and cauda equina enhancement on MRI. Diagnosis of early GBS can be challenging, as CSF and electrodiagnostic studies can be normal/non-diagnostic in the first 1–2 weeks. We describe a case of early GBS with cauda equina enhancement and lumbosacral plexus abnormalities on MR neurography, seen only three days after symptoms onset and before any diagnostic abnormalities in CSF or electrodiagnostic testing were detected. <h3>Design/Methods:</h3> NA <h3>Results:</h3> A 67-year-old man presented with a 3-day history of rapidly progressive gait instability and leg weakness, 14 days after an uncomplicated L5-S1 fusion. Diffuse arm and leg weakness, distal leg sensory loss, hypoactive arm reflexes and absent leg reflexes were detected on exam. CSF analysis showed normal cells and protein (55mg/dL, reference&lt;60mg/dl). Electrodiagnostic testing showed mildly prolonged F-response latencies of the median and ulnar nerves, absent peroneal F-response, normal tibial F-response latency and absent tibial H-responses, without other findings suggestive of demyelination, and normal needle EMG. Lumbar spine MRI showed enhancement of ventrally positioned nerve roots of the cauda equina and no central or foraminal stenosis. Lumbosacral plexus MR neurography showed prominent enlargement, hyperintensity and enhancement of bilateral lower lumbosacral nerve roots and the proximal sciatic nerves. Plasma exchange was initiated with subsequent improvement in his symptoms and exam findings. <h3>Conclusions:</h3> Diagnosis of early GBS can be challenging, as CSF and electrodiagnostic testing can be normal/non-diagnostic. MRI and MR neurography are useful surrogate tests which may have greater sensitivity in detecting early GBS compared to CSF and electrodiagnostic testing. Involvement of the lumbosacral plexus by imaging is a novel finding, which can further assist in diagnosing early GBS cases. <b>Disclosure:</b> Dr. Weng has nothing to disclose. The institution of Darryl Sneag, 12603 has received research support from GE Healthcare. Dr. Pavlakis has nothing to disclose.