Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
Department of Clinical Neurophysiology, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
Pract Neurol. 2023 Nov 23;23(6):516-518. doi: 10.1136/pn-2023-003788.
A 45-year-old man presented with an isolated sciatic mononeuropathy, which then evolved into a lumbosacral radiculoplexus neuropathy. His initial symptoms included lower limb pain, sensory disturbance and later weakness, without autonomic dysfunction. Neurophysiology suggested a postganglionic neuropathy. MR and ultrasound scans of the thighs showed right sciatic nerve thickening, and CSF analysis showed albuminocytological dissociation. Fluorodeoxyglucose positron emission tomography (FDG PET) was unremarkable. He then developed orthostatic symptoms and urinary disturbance, and was found to have an IgM paraprotein. Fat aspirate, cardiac and whole-body imaging found no amyloid deposition, and genetic testing for transthyretin amyloidosis was negative. A bone marrow biopsy was unremarkable. However, neuropathology review of a proximal, fascicular nerve biopsy identified a lambda chain-restricted plasma cell population with positive Congo red staining, leading to a diagnosis of peripheral nerve restricted amyloid light amyloidosis. We discuss the diagnostic approach to this case from the perspectives of neurology, neurophysiology, radiology and neuropathology.
一位 45 岁男性出现孤立性坐骨神经单神经病，随后发展为腰骶神经根丛神经病。他最初的症状包括下肢疼痛、感觉障碍，随后出现无力，但没有自主神经功能障碍。神经生理学提示节后神经病。大腿的磁共振和超声扫描显示右侧坐骨神经增粗，CSF 分析显示蛋白细胞分离。氟脱氧葡萄糖正电子发射断层扫描（FDG PET）无明显异常。随后他出现直立症状和排尿障碍，并发现存在 IgM 副蛋白。脂肪抽吸、心脏和全身成像未发现淀粉样物质沉积，转甲状腺素蛋白淀粉样变性的基因检测结果为阴性。骨髓活检无明显异常。然而，对近端束状神经活检的神经病理学复查发现，有一个 lambda 链限制的浆细胞群，刚果红染色阳性，导致诊断为周围神经限制型轻链淀粉样变性。我们从神经病学、神经生理学、放射学和神经病理学的角度讨论了该病例的诊断方法。
