Background

Pure neuritic leprosy (PNL) is uncommon form of leprosy involving peripheral nerves. Some isolated case reports have shown imaging changes in the central nervous system (CNS) and also impairment in visual evoked potential (VEP), somatosensory evoked potential (SSEP) and brain stem auditory-evoked potentials (BAEPs) parameters in PNL, but there is lack of large study. This prospective observational study evaluates impairment in these central conduction studies among PNL patients.

Methods

We screened patients with leprosy presenting with features of neuropathy and/or thickened nerves. Patients with bacilli-positive nerve biopsies were included in the study and subjected to routine tests along with nerve conduction study (NCS), VEP, tibial SSEP and BAEPs. Parameters of these studies were analyzed based on data from previous studies.

Results

Of 76 patients screened for PNL 49 had positive findings in biopsy. Most of patients were male and mean age group was 46.35 ± 15.35 years. Mononeuritis multiplex was most common NCS pattern in 46.93% (23/49) patients. We found abnormal VEP in 13 out of 35 patients (37.14%). Similarly abnormal SSEP and BAEPs among 42.85% and 40% patients respectively.

Discussion

This study shows that in PNL significant number of patients have subclinical CNS involvement. Exact pathophysiology of CNS involvement is not known till now but study of VEP, SSEP and BAEPs parameter may help in early diagnosis of PNL.

中文翻译：

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从外围到中心，纯神经炎性麻风病不为人知的故事：一项电生理学研究

背景

纯神经炎性麻风病 (PNL) 是一种罕见的累及周围神经的麻风病。一些孤立的病例报告显示中枢神经系统（CNS）的影像学变化以及 PNL 中视觉诱发电位（VEP）、体感诱发电位（SSEP）和脑干听觉诱发电位（BAEP）参数的损害，但缺乏大规模的研究。这项前瞻性观察性研究评估了 PNL 患者中枢传导研究的损伤。

方法

我们筛查了具有神经病变和/或神经增粗特征的麻风患者。神经活检呈杆菌阳性的患者被纳入研究中，并接受常规测试以及神经传导研究 (NCS)、VEP、胫骨 SSEP 和 BAEP。这些研究的参数是根据先前研究的数据进行分析的。

结果

在接受 PNL 筛查的 76 名患者中，有 49 名患者的活检结果呈阳性。大多数患者为男性，平均年龄为 46.35 ± 15.35 岁。多发性单神经炎是 46.93% (23/49) 患者中最常见的 NCS 模式。我们发现 35 名患者中有 13 名 VEP 异常（37.14%）。同样，分别有 42.85% 和 40% 的患者出现 SSEP 和 BAEP 异常。

讨论

这项研究表明，在 PNL 中，大量患者存在亚临床中枢神经系统受累。目前尚不清楚 CNS 受累的确切病理生理学，但 VEP、SSEP 和 BAEPs 参数的研究可能有助于 PNL 的早期诊断。