Background Chronic inflammatory demyelinating polyneuropathy (CIDP) is a common yet underdiagnosed cause of potentially treatable chronic sensorimotor neuropathy. The classical form of the disease is characterised by symmetrical weakness in both distal and proximal muscle groups accompanied by sensory dysfunction and diminished tendon reflexes lasting more than 2 months. Method The diagnosis of CIDP is supplemented by electrodiagnostic studies and biopsy findings confirming demyelination, in accordance with well-established diagnostic criteria. Atypical presentations of CIDP often pose a diagnostic challenge. Results In this paper, we present a case of isolated lower limb involvement due to CIDP to raise awareness of this focal lower limb variant. Of particular, significance is the use of lumbosacral plexus MRI to assist in the diagnosis. Conclusion Focal CIDP is an atypical presentation that should be considered in patients presenting with chronic monomelic neuropathy and should be investigated with electrodiagnostic studies, lumbar puncture, nerve biopsy and MRI of the nerve roots and plexuses.

中文翻译：

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慢性炎症性脱髓鞘性多发性神经根神经病主要表现为坐骨单体神经病


背景 慢性炎症性脱髓鞘性多发性神经病（CIDP）是可治疗的慢性感觉运动神经病的常见但诊断不足的原因。该疾病的经典形式的特征是远端和近端肌肉群对称无力，伴有感觉功能障碍和腱反射减弱，持续超过 2 个月。方法 根据既定的诊断标准，CIDP 的诊断辅以电诊断研究和证实脱髓鞘的活检结果。 CIDP 的非典型表现常常给诊断带来挑战。结果在本文中，我们提出了一个因 CIDP 导致孤立性下肢受累的病例，以提高对这种局灶性下肢变异的认识。尤其重要的是利用腰骶丛MRI来辅助诊断。结论 局灶性 CIDP 是一种非典型表现，对于慢性单体性神经病患者应予以考虑，并应通过电诊断研究、腰椎穿刺、神经活检以及神经根和神经丛 MRI 进行检查。