From periphery to center, untold story of pure neuritic leprosy: an electrophysiological study.

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.

Pure Neuritic Leprosy with Bilateral Foot Drop and Central Nervous Involvement: A Clinical, Electrophysiological, and MR Correlation.

BACKGROUND: Central nervous system (CNS) involvement in leprosy is sparsely documented. Neurophysiological tests and magnetic resonance imaging (MRI) helps in demonstrating CNS involvement in the patient of pure neuritic leprosy. OBJECTIVES: To demonstrate CNS involvement in pure neuritic leprosy. METHODS: Detailed clinical presentation and skin lesions were evaluated. Sural nerve biopsy, MRI diffusion tensor imaging of spinal cord and optic nerve were performed. Visual evoked potential and tibial somatosensory evoked potential were done. Their clinical, electrophysiological, and MRI were done at follow-up visits. RESULTS: We report three patients of pure neuritic leprosy with bilateral foot drop as the initial presentation. MRI T2W sequence of cervico dorsal cord showed dorsal column hyperintensity in two patients. Diffusion-weighted MR revealed decrease fractional anisotropy and an increase in the apparent diffusion coefficient. Similar findings were also noted in the optic nerves. The patients were managed with multidrug therapy multibacillary regimen and steroid in tapering dose. At follow-up, they showed clinical improvement in vision and power of ankle dorsiflexor. CONCLUSIONS: Patients of pure neuritic leprosy may manifest with bilateral foot drop with the involvement of posterior column and cranial nerves.