Leprosy is a chronic infectious disease caused by Mycobacterium leprae. It can lead to damage of the nerve. Although the incidence of leprosy is very low in South Korea, a large number of people are immigrating to South Korea from countries with a high prevalence of leprosy. We report a case of leprosy confirmed by nerve biopsy. The patient was from Nepal who presented with progressive and asymmetric sensory loss. Leprosy can be considered as a differential diagnosis in patients with progressive and asymmetric sensory loss, especially when patients are from leprosy endemic countries.

Background
Clinical spectrum of immunoglobulin M (IgM) monoclonal gammopathy varies from IgM monoclonal gammopathy of unknown significance (IgM-MGUS) to hematological malignancies. We evaluated the clinical features, electrophysiological characteristics, and prognosis of patients with peripheral neuropathy associated with IgM monoclonal gammopathy (PN-IgM MG).
Methods
We retrospectively evaluated 25 patients with PN-IgM MG. Peripheral neuropathy was classified as axonal, demyelinating, or undetermined, based on electrophysiological studies. We classified the enrolled patients into the IgM-MGUS and malignancy groups, and compared the clinical and electrophysiological features between the groups.
Results
Fifteen patients had IgM-MGUS and 10 had hematologic malignancies (Waldenström’s macroglobulinemia: two and B-cell non-Hodgkin’s lymphoma: eight). In the electrophysiological evaluation, the nerve conduction study (NCS) criteria for demyelination were met in 86.7% of the IgM-MGUS group and 10.0% of the malignancy group. In particular, the distal latencies of the motor NCS in the IgM-MGUS group were significantly prolonged compared to those in the malignancy group (median, 9.1 ± 5.1 [IgM-MGUS], 4.2 ± 1.3 [malignancy], p = 0.003; ulnar, 5.4 ± 1.9 [IgM-MGUS], 2.9 ± 0.9 [malignancy], p = 0.001; fibular, 9.3 ± 5.1 [IgM-MGUS], 3.8 ± 0.3 [malignancy], p = 0.01; P-posterior tibial, 8.3 ± 5.4 [IgM-MGUS], 4.4 ± 1.0 [malignancy], p = 0.04). Overall treatment responses were significantly worse in the malignancy group than in the IgM-MGUS group (p = 0.004), and the modified Rankin Scale score at the last visit was higher in the malignancy group than in the IgM-MGUS group (2.0 ± 1.1 [IgM-MGUS], 4.2 ± 1.7 [malignancy], p = 0.001), although there was no significant difference at the initial assessment.
Conclusions
The risk of hematological malignancy should be carefully assessed in patients with PN-IgM MG without electrophysiological demyelination features.

Autoantibodies are present in many autoimmune disorders, including diseases impacting the peripheral nerve, neuromuscular junction, and muscle. Some of these autoantibodies play a vital role in pathogenesis, whereas others are unlikely to be directly pathogenic, but may be useful biomarkers. The identification of autoantibodies is valuable in diagnosis, as well as in establishing a treatment plan in antibody-mediated neuromuscular disorders. This review briefly summarizes antibody, autoantibody, and methods of autoantibody testing for clinicians who treat patients with neuromuscular disorders.

Background
Magnetic resonance (MR) images are useful for diagnosing myopathy. The purpose of this study was to determine the usefulness of lower-limb MR images in Korean patients with distal myopathy.
Methods
We reviewed medical records in the myopathy database from January 2002 to October 2016. We selected 21 patients from 91 unrelated families with distal myopathy: four with GNE myopathy, 11 with dysferlinopathy, and six with ADSSL1 myopathy.
Results
Ten (48%) of the 21 patients were men. The ages of the participants at symptom onset and imaging were 19.2 ± 9.5 and 30.4 ± 9.0 years (mean ± standard deviation), respectively. Their grade on the modified Gardner-Medwin and Walton grade was 3.3 ± 1.7. The strength grade of the knee extensors was not correlated with the Mercuri scale for the quadriceps (r = –0.247, p = 0.115). However, the Medical Research Council grades of the knee flexors, ankle dorsiflexors, and ankle plantar flexors were significantly correlated with the Mercuri scale ratings of the knee flexors (r = –0.497, p = 0.001), tibialis anterior (r = –0.727, p < 0.001), and ankle plantar flexors (r = –0.620, p < 0.001), respectively. T1-weighted MR images showed characteristic fatty replacement patterns that were consistent with the causative genes. Unsupervised hierarchical clustering of the Mercuri scale showed that the main factors contributing to the dichotomy were the causative gene and the clinical severity.
Conclusions
This study is the first to reveal the usefulness of lower-limb MR images in the differential diagnosis of distal myopathy in Korea.

A 73-year-old woman presented with progressive, symmetric distal dominant sensory change followed by motor weakness accompanied with multiple skin lesions. Neurologic examinations and electrophysiologic study revealed demyelinating polyneuropathy. Diagnosis of leprous neuropathy was made with skin biopsy. This rare presentation of leprosy indicates leprosy can be considered as differential diagnosis in patients with clinically evident progressive polyneuropathy.

Myasthenia gravis is an autoimmune disorder affecting neuromuscular junction. Corticosteroid and other immunosuppressive agents are used for the treatment of myasthenia gravis. Tacrolimus may also have a potential role in long-term supression of the immune system. There are limited but promising data to suggest beneficial effects of tacrolimus to control myasthenia gravis and to reduce corticosteroid burden. To date, the largest randomised controlled trial could not demonstrate significant differences in their primary endpoint. Therefore, additional well designed and high quality studies are necessary to determine the effects of tacrolimus on myasthenia gravis.

A 33-year-old woman, previously diagnosed with multifocal acquired demyelinating sensory and motor neuropathy, or Lewis-Sumner syndrome (LSS), presented with diffuse multifocal nerve root swelling at cervical 3th to 7th resembling with neurofibroma. Upon nerve conduction investigations, multifocal conduction block in the upper limb were discovered. In addition, a right mandibular branch of trigeminal nerve hypertrophy resembling schwannoma was found Treatment with intravenous immunoglobulin and steroid improved her symptoms. The observed hypertrophy in the right mandibular branch of the trigeminal nerve was correlated with her symptoms. This study presents a case of LSS mimicking neurofibroma with coexisting cranial and peripheral nerve involvement, emphasizing the usefulness of the magnetic resonance imaging.