Berini, Sarah E.

ABSTRACTIntroductionSjögren syndrome is thought to be a lymphocyte‐driven process. Peripheral nervous system involvement occurs in about 20%–25% of patients. A sensory‐predominant, large‐fiber peripheral neuropathy is most common, and it is usually associated with a subacute to chronic presentation.MethodsWe report a rare case of an acute Sjögren‐associated, sensory predominant, length‐dependent peripheral neuropathy mimicking Guillain–Barré syndrome. The patient presented with sensory ataxia preceded by fever and polyarthralgia. She gave a history of years of dry eyes and dry mouth.ResultsShe had a positive Shirmer test, abnormal salivary gland scan, and positive SS‐A and SS‐B antibodies. A sural nerve biopsy showed an unusual, dense, non‐IgG4, polyclonal, plasma‐cell perivascular infiltrate. The patient responded to treatment with weekly pulse intravenous methylprednisolone.ConclusionsSjögren syndrome can present with acute‐onset, sensory predominant peripheral neuropathy. The role of plasma cells in Sjögren syndrome is unexplored and deserves further study. Muscle Nerve 55: 605–608, 2017

ABSTRACTIntroduction: A 24‐year‐old man with primary hyperoxaluria type 1 (PH1) presented with a rapidly progressive axonal and demyelinating sensorimotor polyradiculoneuropathy shortly after the onset of end‐stage renal disease. His plasma oxalate level was markedly elevated at 107 µmol/L (normal <1.8 µmol/L). Methods: A sural nerve biopsy was performed. Teased fiber and paraffin and epoxy sections were done and morphometric procedures were performed on this sample and on an archived sample from a 22‐year‐old man as an age‐ and gender‐matched control. Embedded teased fiber electron microscopy was also performed. Results: The biopsy revealed secondary demyelination and axonal degeneration. Under polarized light, multiple bright hexagonal, rectangular, and starburst inclusions, typical of calcium oxalate monohydrate crystals, were seen. Conclusions: The proposed mechanisms of nerve damage include disruption of axonal transport due to crystal deposition, toxic effect of oxalate, or nerve ischemia related to vessel occlusion from oxalate crystal deposition. Muscle Nerve 51: 449–454, 2015