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Background We aimed to evaluate the diagnostic accuracy of enzyme-linked immunosorbent assay (ELISA) for anti-muscle specific tyrosine kinase (MuSK) antibody (Ab) in a large cohort of anti-acetylcholine receptor (AChR) Ab-negative generalized myasthenia gravis (MG), and also to investigate clinical contexts for the diagnosis of MuSK MG. Methods A retrospective study of 160 patients with a clinical suspicion of AChR Ab-negative generalized MG was performed. The serum samples were tested for anti-clustered AChR Ab by cell-based assay (CBA), anti-MuSK Ab by ELISA, CBA and/or radioimmunoprecipitation assay (RIPA). Clinical data were compared between anti-MuSK Ab-positive MG and double seronegative (AChR and MuSK) MG groups. Results After excluding non-MG and clustered AChR Ab-positive patients, we identified 89 patients as a cohort of AChR Ab-negative generalized MG. Anti-MuSK Ab was positive by ELISA in 22 (24.7%) patients. While CBA identified five additional anti-MuSK Ab-positive patients, the results of ELISA were mostly consistent with CBA and RIPA with Cohen’s kappa of 0.80 and 0.90, respectively (p Conclusion While confirming the highest sensitivity of CBA for detecting anti-MuSK Ab, our results highlight the clinical pitfalls in making a diagnosis of MuSK MG and may support a diagnostic utility of MuSK-ELISA in clinical practice.

Objectives Hearing loss disrupts the balance of auditory-somatosensory inputs in the cochlear nucleus (CN) of the brainstem, which has been suggested to be a mechanism of tinnitus. This disruption results from maladaptive auditory-somatosensory plasticity, which is a form of axonal sprouting. Axonal sprouting is promoted by transforming growth factor (TGF)-β signaling, which can be inhibited by losartan. We investigated whether losartan prevents maladaptive auditory-somatosensory plasticity after hearing loss. Methods The study consisted of two stages: determining the time course of auditory-somatosensory plasticity following hearing loss and preventing auditory-somatosensory plasticity using losartan. In the first stage, rats were randomly divided into two groups: a control group that underwent a sham operation and a deaf group that underwent cochlea ablation on the left side. CNs were harvested 1 and 2 weeks after surgery. In the second stage, rats were randomly divided into either a saline group that underwent cochlear ablation on the left side and received normal saline or a losartan group that underwent cochlear ablation on the left side and received losartan. CNs were harvested 2 weeks after surgery. Hearing was estimated with auditory brainstem responses (ABRs). Western blotting was performed for vesicular glutamate transporter 1 (VGLUT1), reflecting auditory input; vesicular glutamate transporter 2 (VGLUT2), reflecting somatosensory input; growth-associated protein 43 (GAP-43), reflecting axonal sprouting; and p-Smad2/3. Results Baseline ABR thresholds before surgery ranged from 20 to 35 dB sound pressure level. After cochlear ablation, ABR thresholds were higher than 80 dB. In the first experiment, VGLUT2/VGLUT1 ratios did not differ significantly between the control and deaf groups 1 week after surgery. At 2 weeks after surgery, the deaf group had a significantly higher VGLUT2/VGLUT1 ratio compared to the control group. In the second experiment, the losartan group had a significantly lower VGLUT2/VGLUT1 ratio along with significantly lower p-Smad3 and GAP-43 levels compared to the saline group. Conclusion Losartan might prevent axonal sprouting after hearing loss by blocking TGF-β signaling thereby preventing maladaptive auditory-somatosensory plasticity.

Additional file 1: Supplementary Table. The codes for prediction of the cognitive impairment with the two drawing test.

Background The Clock Drawing Test (CDT) and Rey–Osterrieth Complex Figure Test (RCFT) are widely used as a part of neuropsychological test batteries to assess cognitive function. Our objective was to confirm the prediction accuracies of the RCFT-copy and CDT for cognitive impairment (CI) using convolutional neural network algorithms as a screening tool. Methods The CDT and RCFT-copy data were obtained from patients aged 60–80 years who had more than 6 years of education. In total, 747 CDT and 980 RCFT-copy figures were utilized. Convolutional neural network algorithms using TensorFlow (ver. 2.3.0) on the Colab cloud platform (www.colab.research.google.com) were used for preprocessing and modeling. We measured the prediction accuracy of each drawing test 10 times using this dataset with the following classes: normal cognition (NC) vs. mildly impaired cognition (MI), NC vs. severely impaired cognition (SI), and NC vs. CI (MI + SI). Results The accuracy of the CDT was better for differentiating MI (CDT, 78.04 ± 2.75; RCFT-copy, not being trained) and SI from NC (CDT, 91.45 ± 0.83; RCFT-copy, 90.27 ± 1.52); however, the RCFT-copy was better at predicting CI (CDT, 77.37 ± 1.77; RCFT, 83.52 ± 1.41). The accuracy for a 3-way classification (NC vs. MI vs. SI) was approximately 71% for both tests; no significant difference was found between them. Conclusions The two drawing tests showed good performance for predicting severe impairment of cognition; however, a drawing test alone is not enough to predict overall CI. There are some limitations to our study: the sample size was small, all the participants did not perform both the CDT and RCFT-copy, and only the copy condition of the RCFT was used. Algorithms involving memory performance and longitudinal changes are worth future exploration. These results may contribute to improved home-based healthcare delivery.

Although the evidence for attentional bias to pain-related information among individuals with chronic pain has been well established, there are a number of inconsistencies in the research that have been observed due to sample characteristics. Therefore, the present study expanded upon previous studies by including patients with a variety of chronic pain conditions and compared a chronic pain patient sample with healthy community sample. We also investigated how pain catastrophizing and other psychological factors in chronic pain patients affected attentional patterns to pain-related information. Forty chronic pain patients from the departments of neurology and rheumatology of an academic medical center hospital and 40 participants without chronic pain from a university that is located in Seoul, South Korea were recruited for the present study. Patients observed pictures of faces displaying pain that were presented simultaneously with faces with neutral expressions, while their eye movements were measured using an eye-tracking system. Independent t-tests were conducted to investigate attentional preferences to pain stimuli between the chronic pain and control groups. No significant attentional differences in pain-neutral pairs were found for both chronic pain and control group. A one-way MANOVA was conducted to examine the role of pain catastrophizing on psychological factors and attentional engagement to pain stimuli. No significant results for the attentional bias to pain stimuli among chronic pain patients may indicate that chronic pain patients who have suffered from chronic pain for a long time and have been treated for their chronic pain in the hospital may interpret pain-related information not as threatening. Clinical implications related to use in pain treatment and future research suggestions are discussed.

Sarcopenia, which refers to the muscle loss that accompanies aging, is a complex neuromuscular disorder with a clinically high prevalence and mortality. Despite many efforts to protect against muscle weakness and muscle atrophy, the incidence of sarcopenia and its related permanent disabilities continue to increase. In this study, we found that treatment with human placental hydrolysate (hPH) significantly increased the viability (approximately 15%) of H2 O2 -stimulated C2C12 cells. Additionally, while H2 O2 -stimulated cells showed irregular morphology, hPH treatment restored their morphology to that of cells cultured under normal conditions. We further showed that hPH treatment effectively inhibited H2 O2 -induced cell death. Reactive oxygen species (ROS) generation and Mstn expression induced by oxidative stress are closely associated with muscular dysfunction followed by atrophy. Exposure of C2C12 cells to H2 O2 induced abundant production of intracellular ROS, mitochondrial superoxide, and mitochondrial dysfunction as well as myostatin expression via nuclear factor-κB (NF-κB) signaling; these effects were attenuated by hPH. Additionally, hPH decreased mitochondria fission-related gene expression (Drp1 and BNIP3) and increased mitochondria biogenesis via the Sirt1/AMPK/PGC-1α pathway and autophagy regulation. In vivo studies revealed that hPH-mediated prevention of atrophy was achieved predominantly through regulation of myostatin and PGC-1α expression and autophagy. Taken together, our findings indicate that hPH is potentially protective against muscle atrophy and oxidative cell death.

Background and purpose Upper respiratory infection (URI), including influenza, may exacerbate the symptoms of myasthenia gravis (MG), which is an autoimmune disease that causes muscle weakness. There is also concern that the influenza vaccine may trigger or worsen autoimmune diseases. The objective of this study was to determine the impacts of influenza infection and vaccination on symptom severity in MG patients. Methods Patients diagnosed with MG were enrolled from 10 university-affiliated hospitals between March and August 2015. Subjects completed a questionnaire at the first routine follow-up visit after enrolling in the study. The patient history was obtained to determine whether a URI had been experienced during the previous winter, if an influenza vaccination had been administered before the previous winter, and whether their MG symptoms were exacerbated during or following either a URI or vaccination. Influenza-like illness (ILI) was defined and differentiated from the common cold as a fever of ≥38°C accompanied by a cough and/or a sore throat. Results Of the 258 enrolled patients [aged 54.1±15.2 years (mean±SD), 112 men, and 185 with generalized MG], 133 (51.6%) had received an influenza vaccination and 121 (46.9%) had experienced a common cold (96 patients) or ILI (25 patients) during the analysis period. MG symptoms were aggravated in 10 (40%) patients after ILI, whereas only 2 (1.5%) experienced aggravation following influenza vaccination. The rate of symptom aggravation was significantly higher in patients experiencing an ILI (10/25, 40%) than in those with the common cold (15/96, 15.6%, p=0.006). Conclusions The results of this study suggest that the potential risk of aggravating autoimmune disease is higher for ILI than for influenza vaccination, which further suggests that influenza vaccination can be offered to patients with MG.

Introduction Several clinical studies using tacrolimus revealed reasonable therapeutic mechanisms and efficacy in patients with myasthenia gravis (MG). However, long-period studies in a large number of patients with MG are limited; therefore, the aim of this study was to investigate the therapeutic efficacies and safety of tacrolimus in patients with MG during a 12-month follow-up period. Methods Tacrolimus was administered to 150 patients with MG who were recruited based on the inclusion criteria. Fifteen medical centers in Korea participated in this study. The efficacy of tacrolimus was assessed using MG composite scales (MGCS) and the prednisolone-sparing effect. And the adverse drug reactions (ADRs) of tacrolimus were monitored in each patient from the beginning of tacrolimus treatment to the end of the follow-up period. Results After starting tacrolimus, the 32 patients were affected by ADRs, and consequentially 134 patients of the enrolled patients were followed up for 12 months. They showed that the mean prednisolone dosage significantly decreased (6.1 ± 7.6 mg/day), compared to that in the baseline (11.3 ± 9.5 mg/day), and MGCS significantly improved after 12 months of tacrolimus treatment, compared to that at the baseline. Conclusions Our study showed that tacrolimus would be an effective immunosuppressant as an initial therapeutic agent in patients with MG; in addition, it showed tolerable safety profiles during the 12-month follow-up evaluation.

Eosinophilic granulomatosis with polyangiitis (EGPA) is an immune related systemic disease that is caused by vasculitis affecting multiple organ systems. It is characterized by asthma, fever, eosinophilia, cardiac problems, renal injury, and peripheral neuropathy. In this report, we describe a patient with EGPA with concurrent cerebral infarction and acute polyneuropathy mimicking a Guillain-Barre syndrome (GBS). A 46-year-old man presented with rapidly progressing gait disturbance, muscular weakness, and tingling sensation in all four limbs. A nerve conduction study revealed sensorimotor polyneuropathy in all four limbs, and a test of the cerebrospinal fluid showed an albumin-cytologic dissociation. In addition, brain magnetic resonance imaging (MRI) using fluid-attenuated inversion recovery and diffusion weighted MRI revealed high signal intensity lesions with gadolinium enhancement on T1-weighted MRI in the right caudate nucleus. After performing laboratory tests, paranasal sinus computed tomography, and a nasal smear, the patient was diagnosed with EGPA and treated with high dose glucocorticoid and oral cyclophosphamide. In conclusion, our findings indicate that a diagnosis of EGPA should be considered when a patient presents with rapidly progressing polyneuropathy mimicking a GBS along with unusual systemic symptoms or brain lesions.

Objectives: We compared validity of 2010 McDonald and newly proposed 2016 Magnetic Resonance Imaging in Multiple Sclerosis (MAGNIMS) criteria for dissemination in space (DIS) in predicting the conversion to clinically definite multiple sclerosis (CDMS) in patients with clinically isolated syndrome (CIS). Methods: Between 2006 and 2016, we enrolled 170 patients who had a first clinical event suggestive of multiple sclerosis (MS) from seven referral hospitals in Korea. Patients were classified into two groups based on the main outcome at the last follow-up: CDMS converters, who experienced a second attack, and non-converters. Results: Of 170 patients with mean follow-up duration of 54 months, 51% converted to CDMS. The sensitivity, specificity, accuracy, and positive and negative predictive values of 2010 McDonald criteria were 70.9%, 63.1%, 67.1%, 66.3%, and 67.9%, and those for 2016 MAGNIMS criteria were 88.4%, 46.4%, 67.7%, 62.8%, and 79.6%, respectively. When we excluded 80 patients who underwent disease-modifying therapy before the second clinical event, the specificity increased to 92.3% and 84.6%, but the sensitivity decreased to 58.8% and 82.4% for 2010 McDonald and 2016 MAGNIMS criteria, respectively. Conclusion: 2016 MAGNIMS magnetic resonance imaging (MRI) criteria for DIS showed higher sensitivity but lower specificity than 2010 McDonald criteria in predicting conversion to CDMS in CIS patients.

Amyotrophic lateral sclerosis (ALS), the most common adult onset motor neuron disease, is pathologically characterized by progressive loss of the upper and lower motor neurons. Mutations in the Cu/Zn superoxide dismutase gene (SOD1) account for about 20% of familial ALS cases and a small percentage of sporadic ALS (SALS) cases, and have revealed a validated genotype-phenotype correlation. Herein, we report a p.Gly13Arg mutation in SOD1 exon 1 in a patient with SALS who presented with a rapidly progressive course, predominantly affecting the lower motor neurons. A 48-year-old man presented with progressive weakness and muscle atrophy of the left upper and lower limbs, followed by muscle fasciculation and cramping. The clinical features of the patient were clearly suggestive of ALS, and implied a sporadic form with rapid progression, predominantly affecting the lower motor neurons. Sequencing of the SOD1 gene by PCR revealed a missense mutation of G to C (c.37G>C) in exon 1, and amino acid substitution of glycine by arginine (p.Gly13Arg). This is the first case identifying the p.Gly13Arg mutation of SOD1 in the Korean population, and clinical assessments of this patient revealed a different phenotype compared with other cases.

Background Multiple sclerosis (MS) is an immune-associated inflammatory disorder of the central nervous system and results in serious disability. Although many disease-modifying therapy drugs have been developed, these drugs have shown limited clinical efficacy and some adverse effects in previous studies, therefore, there has been reasonable need for less harmful and cost-effective therapeutics. Herein, we tested the anti-inflammatory effect of sulforaphane (SFN) in a mouse model of experimental autoimmune encephalomyelitis (EAE). Methods The EAE mice were randomly assigned into two experimental groups: the phosphate-buffered saline (PBS)-treated EAE group and SFN-treated EAE group. After EAE mice induction by auto-immunization against the myelin oligodendrocyte glycoprotein peptide, we evaluated EAE symptom scores and biochemical analyses such as infiltration of inflammatory cells and demyelination of the spinal cord. Furthermore, western blotting was performed using the spinal cords of EAE mice. Results In the behavioral study, the SFN-treated EAE mice showed favorable clinical scores compared with PBS-treated EAE mice at the 13th day (1.30 ± 0.15 vs. 1.90 ± 0.18; P = 0.043) and 14th day (1.80 ± 0.13 vs. 2.75 ± 0.17; P = 0.003). Additionally, the biochemical studies revealed that SFN treatment inhibited the inflammatory infiltration, demyelinating injury of the spinal cords, and the up-regulation of inducible nitric oxide synthase in the EAE mice. Conclusion The SFN treatment showed anti-inflammatory and anti-oxidative effects in the EAE mice. Conclusively, this study suggests that SFN has neuroprotective effects via anti-inflammatory processing, so it could be a new therapeutic or nutritional supplement for MS., Graphical Abstract

We investigated the prevalence and mechanisms of neurological deterioration after endovascular thrombectomy. Between January 2011 and October 2017, acute ischemic stroke patients treated by endovascular thrombectomy in a tertiary university hospital were included. Early neurological deterioration (END) was defined as an increase of 2 or more National Institute of Health Stroke Scale (NIHSS) compared to the best neurological status after stroke within 7 days. The END mechanism was categorized into ischemia progression, symptomatic hemorrhage, and brain edema. A total of 125 acute ischemic stroke patients received endovascular thrombectomy. Neurological deterioration was detected in 44 patients, and 38 cases (86.4% of END) occurred within 72 h. The END mechanism included 20 ischemia progression, 16 brain edema and 8 hemorrhagic transformation cases. Multivariable logistic regression analysis revealed that the patients who experienced END were more likely to have poor functional outcome defined as modified Rankin scale 3–6 at 90 days than neurologically stable patients (odds ratio (OR) = 4.06, confidence interval (CI) = 1.39–11.9). The risk factor of END due to ischemia progression was stroke subtype of large artery atherosclerosis (OR = 6.28, CI = 1.79–22.0). Successful recanalization (OR = 0.11, CI = 0.03–0.39) and NIHSS after endovascular thrombectomy (OR = 1.15 per one-point increase, CI = 1.06–1.24) were significantly associated with END due to hemorrhage or brain edema. Neurological deterioration frequently occurs after endovascular thrombectomy, and the risk factors of END differ according to the mechanism of END.

Background The motor and sensory symptoms caused by compressive radial neuropathy are well-known, but the involvement of the autonomic nervous system or the dermatologic symptoms are less well known. We report an unusual case of compressive radial neuropathy with reversible reddish skin color change. Case presentation A 42-year-old man was referred for left wrist drop, finger drop and a tingling sensation over the lateral dorsum of the left hand. Based on clinical information, neurologic examinations and electrophysiologic studies, he was diagnosed with compressive radial neuropathy. In addition, a reddish skin color change was observed at the area of radial sensory distribution. After two weeks of observation without specific treatment, the skin color had recovered along with a marked improvement in weakness and aberrant sensation. Conclusions Compressive radial neuropathy with a reversible reddish skin color change is unusual and is considered to be due to vasomotor dysfunction of the radial autonomic nerve. Compressive radial neuropathy is presented with not only motor and sensory symptoms but also autonomic symptoms; therefore, careful examination and inspection are needed at diagnosis.

Objectives: To evaluate the validity of the revised 2017 McDonald criteria for multiple sclerosis (MS) compared with the 2010 McDonald criteria to predict conversion to clinically definite multiple sclerosis (CDMS) in patients with clinically isolated syndrome (CIS). Methods: A total of 163 patients from seven referral hospitals in Korea, who experienced a first clinical event suggestive of MS between 2006 and 2017, were enrolled. Patients were stratified into two groups according to outcome at the last visit: CDMS converters who experienced a second clinical event and non-converters. Results: Of the 163 patients with a mean follow-up of 63 months, 60% converted to CDMS. The sensitivity, specificity, positive and negative predictive values and accuracy were, respectively, 88.8%, 43.1%, 70.2%, 71.8% and 70.6% for the 2017 McDonald criteria and 53.1%, 69.2%, 72.2%, 49.5% and 59.5% for the 2010 McDonald criteria. After exclusion of 82 patients who received disease-modifying agents before the second attack, the specificity of the 2017 and 2010 McDonald criteria increased to 85.0% and 95.0%, but sensitivity decreased to 83.6% and 47.5%, respectively. Conclusion: The 2017 McDonald criteria afforded higher sensitivity and accuracy but lower specificity compared with the 2010 McDonald criteria for prediction of conversion to CDMS in Korean CIS patients.

Introduction: Split hand is considered to be a spe- cific feature of amyotrophic lateral sclerosis (ALS). Methods: We evaluated the pattern difference of intrinsic hand muscles of upper limb-onset ALS (UL-ALS), upper limb-onset progressive muscular atrophy (UL-PMA), brachial amyotrophic diplegia (BAD), and Hirayama disease (HD) by measuring objective electrophysiological markers. Results: The abductor digiti minimi (ADM)/abductor pollicis brevis (APB) compound muscle action potential (CMAP) amplitude ratio was significantly higher in UL- ALS than other variants, but a considerable proportion of UL- ALS cases had an amplitude ratio in the range of other var- iants. Absent APB CMAP and abnormally high ADM/APB CMAP amplitude ratio (4) occurred only with UL-ALS. Con- versely, an absent ADM CMAP was identified only in UL-PMA and BAD. Conclusions: The absolute ADM/APB CMAP ampli- tude ratio was not specific for ALS; however, several findings from simple electrophysiological measurements may help pre- dict prognosis in patients with motor neuron diseases and may be early diagnostic markers for ALS. Muscle Nerve 51: 333-337, 2015

Background and Purpose— The aim of this study was to determine the association between 25-hydroxyvitamin D (25(OH)D) and neuroimaging correlates of cerebral small vessel disease. Methods— We identified 759 consecutive patients with acute ischemic stroke or transient ischemic attack. Lacunes, white matter hyperintensity, and cerebral microbleed (CMB) were assessed using MR images. Deep CMB was defined as the presence of CMB in basal ganglia, thalamus, or brain stem. The association between 25(OH)D and small vessel disease was tested using linear and logistic regression analyses. Results— Mean age was 68 (±13) years. Mean level of 25(OH)D was 34.1±17.8 nmol/L. On bivariate analysis, a 25-nmol/L decrease in 25(OH)D was associated with lacunes (regression coefficient, 0.23; 95% confidence interval [CI], 0.02–0.45), severe white matter hyperintensity (odds ratio, 2.05; 95% CI, 1.41–3.08), and deep CMB (odds ratio, 1.28; 95% CI, 1.01–1.63). Also, 25(OH)D deficiency (≤25 nmol/L) was associated with lacunes (regression coefficient, 0.5; 95% CI, 0.04–0.95), severe white matter hyperintensity (odds ratio, 2.74; 95% CI, 1.31–6.45), and deep CMB (odds ratio, 1.68; 95% CI, 1.03–2.78). The association remained significant even after multivariable adjustment and in the subgroup of previously healthy patients. Conclusions— 25(OH)D is inversely associated with lacunes, white matter hyperintensity, and deep CMB. Our findings suggest that 25(OH)D is linked to small vessel disease, and in future trials it should be tested whether 25(OH)D supplementation can prevent small vessel disease.

Background: There are currently few studies regarding late-onset neuromyelitis optica spectrum disorder (LO-NMOSD). Objective: We aimed to describe the characteristic features of patients with LO-NMOSD in Korea. Methods: Anti-aquaporin-4 antibody-positive patients with neuromyelitis optica spectrum disorder (NMOSD) from nine tertiary hospitals were reviewed retrospectively. The patients were divided into two groups based on age of onset: LO-NMOSD (⩾50 years of age at onset) versus early-onset neuromyelitis optica spectrum disorder (EO-NMOSD) (Results: Among a total of 147 patients (125 female; age of onset, 39.4 ± 15.2 years), 45 patients (30.6%) had an age of onset of more than 50 years. Compared to patients with EO-NMOSD, patients with LO-NMOSD had more frequent isolated spinal cord involvement at onset (64.4% vs 37.2%, p = 0.002), less frequent involvement of the optic nerve (40.0% vs 67.7%, p = 0.002), and less frequent brain MRI lesions (31.1% vs 50.0%, p = 0.034). Furthermore, there was a significant positive correlation between age of onset and Expanded Disability Status Scale (EDSS) score at last follow-up ( r = 0.246, p = 0.003). Conclusion: Age of onset could be an important predictor of lesion location and clinical course of patients with NMOSD.

Glycogen synthase kinase-3β (GSK-3β) inhibitors have been suggested as a core regulator of apoptosis and have been investigated as therapeutic agents for neurodegenerative diseases, including amyotrophic lateral sclerosis. However, GSK-3β has an interesting paradoxical effect of being proapoptotic during mitochondrial-mediated intrinsic apoptosis but antiapoptotic during death receptor-mediated extrinsic apoptosis. We assessed the effect of low to high doses of a GSK-3β inhibitor on survival and apoptosis of the NSC-34 motor neuron-like cell line after serum withdrawal. Then, we identified changes in extrinsic apoptosis markers, including Fas, Fas ligand, cleaved caspase-8, p38α, and the Fas-Daxx interaction. The GSK-3β inhibitor had an antiapoptotic effect at the low dose but was proapoptotic at the high dose. Proapoptotic effect at the high dose can be explained by increased signals in cleaved caspase-8 and the motor neuron-specific p38α and Fas-Daxx interaction. Our results suggest that GSK-3β inhibitor dose may determine the summation effect of the intrinsic and extrinsic apoptosis pathways. The extrinsic apoptosis pathway might be another therapeutic target for developing a potential GSK-3β inhibitor.

Introduction: The motor unit number index (MUNIX) refers to an electrophysiological method that measures the number of motor units in the surface electromyographic interference pattern (SIP) recorded during graded muscle contractions. MUNIX studies of limb muscles have been conducted, but MUNIX studies of bulbo-facial muscles have not been reported. Methods: We assessed bilateral orbicularis oculi muscles using MUNIX, and the reference values and reproducibility of MUNIX and motor unit size index (MUSIX) were investigated in healthy subjects. Results: In this study, MUNIX was applied successfully to the orbicularis oculi muscles and showed good reproducibility. The correlation coefficients for MUNIX and MUSIX were 0.803 and 0.592, respectively, and the coefficients of variation were 20.9% and 8.5%, respectively. Conclusions: The MUNIX procedure for the orbicularis oculi muscle would be a useful tool for evaluating bulbar symptoms, especially in amyotrophic lateral sclerosis. Muscle Nerve 51: 197–200, 2015

Background Glycogen synthase kinase-3β (GSK-3β) activity plays a central role in motor neuron degeneration. GSK-3β inhibitors have been shown to prolong motor neuron survival and suppress disease progression in amyotrophic lateral sclerosis (ALS). In this study, we evaluated the therapeutic effects of a new GSK-3b inhibitor, JGK-263, on ALS in G93A SOD1 transgenic mice. Methods Previously, biochemical efficacy of JGK-263 was observed in normal and mutant (G93A) hSOD1 -transfected motor neuronal cell lines (NSC34). Based on these previous results, we administered JGK-263 orally to 93 transgenic mice with the human G93A-mutated SOD1 gene. The mice were divided into three groups: a group administered 20 mg/kg JGK-263, a group administered 50 mg/kg JGK-263, and a control group not administered with JGK-263. Clinical status, rotarod test, and survival rates of transgenic mice with ALS were evaluated. Sixteen mice from each group were selected for further biochemical study that involved examination of motor neuron count, apoptosis, and cell survival signals. Results JGK-263 administration remarkably improved motor function and prolonged the time until symptom onset, rotarod failure, and death in transgenic mice with ALS compared to control mice. In JGK-263 groups, choline acetyltransferase (ChAT) staining in the ventral horn of the lower lumbar spinal cord showed a large number of motor neurons, suggesting normal morphology. The neuroprotective effects of JGK-263 in ALS mice were also suggested by western blot analysis of spinal cord tissues in transgenic mice. Conclusion These results suggest that JGK-263, an oral GSK-3β inhibitor, is promising as a novel therapeutic agent for ALS. Still, further biochemical studies on the underlying mechanisms and safety of JGK-263 are necessary.

Background: The Expanded Disability Status Scale (EDSS) is the most widely employed ordinal disability scale in multiple sclerosis (MS). However, how far apart the individual EDSS levels are along the disability spectrum has not been formally quantified. Objectives: The objective of this paper is to generate refined disability weights (DWs) for each of the ordinal EDSS levels. Methods: We performed the person trade-off (PTO) procedure to derive DWs of five representative EDSS categories (2, 4, 6, 7 and 9), and DWs of the remaining EDSS categories were assigned by linear interpolation. The modified Delphi process was used to achieve consensus among raters. Results: DWs were 0.021 for EDSS 2, 0.199 for EDSS 4, 0.313 for EDSS 6, 0.617 for EDSS 7, and 0.926 for EDSS 9. Panel members achieved a high degree of consensus for each DW, as indicated by low coefficients of variation. Conclusions: Our DWs confirmed that EDSS is an ordinal scale with highly variable intervals. The availability of DW for each EDSS level allows direct comparison of each MS outcome state with other health states and provides a foundation for the estimation of the disability-adjusted life-years lost of individual patients.

Highlights • The robotic surgery is a creative and effective technique; however, the risk of this technique has not been fully documented. • We describe neurological complication of hypoglossal nerve palsy after robotic thyroidectomy. • Hypoglossal nerve palsy is usually presented with tongue deviation, atrophy and dysarthria. • Nerve conduction study (NCS) can be used to confirm the hypoglossal nerve injury., Background Endoscopic surgical techniques with robotic system in the thyroid cancer have been reported to show good results and advantages; however the risk of these techniques has not been fully documented. Presentation of the case We experienced an uncommon complicated case of a 20-year-old woman with a papillary thyroid carcinoma. After the robotic thyroidectomy, she complained of the tongue deviation, speech and swallowing difficulties of hypoglossal nerve palsy. Discussion In this case, a few etiologies could be suggested for the development of hypoglossal nerve palsy. It might be associated with direct stretching or entrapment of hypoglossal nerve during tumor resection; lateral placement of the laryngoscope on the tongue base; the hyperinflation of the laryngeal mask airway; and histological disruption of the intraneural connective tissue and blood circulation. Conclusion Although the robotic surgery is a creative technique and has been known to be safe and effective, the risk of this surgery including traumatic nerve injury should be taken into account before surgery.

Aggregation of misfolded protein and resultant intracellular inclusion body formation are common hallmarks of mutant superoxide dismutase (mSOD1)-linked familial amyotrophic lateral sclerosis (FALS) and have been associated with the selective neuronal death. Protein disulfide isomerase (PDI) represents a family of enzymatic chaperones that can fold nascent and aberrant proteins in the endoplasmic reticulum (ER) lumen. Recently, our group found that S-nitrosylated PDI could contribute to protein misfolding and subsequent neuronal cell death. However, the exact role of PDI in the pathogenesis of ALS remains unclear. In this study, we propose that PDI attenuates aggregation of mutant/misfolded SOD1 and resultant neurotoxicity associated with ER stress. ER stress resulting in PDI dysfunction therefore provides a mechanistic link between deficits in molecular chaperones, accumulation of misfolded proteins, and neuronal death in neurodegenerative diseases. In contrast, S-nitrosylation of PDI inhibits its activity, increases mSOD1 aggregation, and increases neuronal cell death. Specifically, our data show that S-nitrosylation abrogates PDI-mediated attenuation of neuronal cell death triggered by thapsigargin. Biotin switch assays demonstrate S-nitrosylated PDI both in the spinal cords of SOD1 (G93A) mice and human patients with sporadic ALS. Therefore, denitrosylation of PDI may have therapeutic implications. Taken together, our results suggest a novel strategy involving PDI as a therapy to prevent mSOD1 aggregation and neuronal degeneration. Moreover, the data demonstrate that inactivation of PDI by S-nitrosylation occurs in both mSOD1-linked and sporadic forms of ALS in humans as well as mice.

We investigated the validity of the 2005 and 2010 McDonald magnetic resonance imaging (MRI) criteria for dissemination in space (DIS) to predict the conversion of clinically definite multiple sclerosis (CDMS) in 94 Korean patients with clinically isolated syndromes (CIS). The sensitivity, specificity, accuracy, positive and negative predictive values of the 2005, 2010 McDonald DIS criteria were comparable to those observed in the Caucasian population. This finding suggests that after careful exclusion of alternative explanations, particularly neuromyelitis optica (NMO) and NMO spectrum disorder (NMOSD), both the 2005 and 2010 McDonald DIS criteria are also useful to predict conversion to CDMS in Korean patients with CIS.

This study was performed to investigate the asymmetry of motor unit number estimate (MUNE) and its longitudinal course in patients with amyotrophic lateral sclerosis. A modified statistical MUNE was performed at the hypothenar muscles bilaterally in a total of 135 patients, and 18 of these patients underwent a follow-up study. The degree of asymmetry varied considerably among those patients whose average MUNE of both sides was moderately reduced, whereas it tended to be low in those whose average MUNE was either severely reduced or close to normal. The rate of motor unit loss was also asymmetric, and two distinct patterns were identified. In patients whose MUNE was greater than 30 in both sides (n = 7), the rate of motor unit loss tended to be greater in the initially more affected side compared with the contralateral one, yielding the so-called lead phenomenon. In contrast, the other patients (n = 11) tended to show the opposite pattern of "catch-up," that is, MUNE declined faster in the initially less affected side compared with the contralateral one. This study shows that not only the MUNE but also the rate of motor unit loss are frequently asymmetric in amyotrophic lateral sclerosis patients.

[This corrects the article DOI: 10.1371/journal.pone.0193723.].

Introduction The purpose of this study was to search for clinical factors predicting the successful generation of baseline muscle motor evoked potentials (mMEPs) in patients undergoing spine surgery and to determine the relationship with postoperative functional outcome. Methods From July 2014 to June 2015, a total of 345 patients underwent spine surgery with intraoperative mMEPs monitoring and were consecutively included in this study. Their demographic features, clinical parameters, and mMEPs recording results were reviewed retrospectively. Results Two hundred and fifty-three (73%) patients showed the successful generation of baseline mMEPs at all recording muscles, and 92 (27%) patients failed to record baseline mMEPs at one or more limb muscles. When we compared the preoperative clinical parameters of the two groups, the latter group (“Failure group”) significantly had a higher male ratio, lower MRC grades, higher Nurick grades, more often cervical/cervicothoracic segment involvement, higher proportion of the presence of spine surgery history, motor deficits, sensory symptoms, bladder/bowel dysfunction, T2-weighted high signal intensity (HSI) of cord at spine MRI compared to the former group (“Success group”) and were older. Among these factors, male sex, cervical/cervicothoracic lesion location the presence of T2-weighted HSI of cord, preoperative Nurick grade, and MRC grade showed a significant contribution for predicting the successful generation of mMEPs. When analyzing predictors for postoperative poor functional outcomes, the success rate of mMEPs recording and lesion etiology were significantly related factors for the aggravation of the Nurick grades before and after surgery. Conclusion Various clinical parameters including lesion location, abnormal cord signal on MRI, preoperative motor power, and functional status were revealed to have a significant relationship with the successful generation of baseline mMEPs. Additionally, the successful generation of mMEPs was one of the indicators for predicting the long-term functional outcome.

Introduction Lateral spread response is observed in patients with hemifacial spasm (HFS) by eletrically stimulating one branch of the facial nerve activates facial muscles innervated by other branches of the facial nerve by electromyography. Nowadays, LSR has been used to confirm adequacy of microvascular decompression (MVD). The aim of this study was to evaluate the prognostic value of intra- and extra-operative lateral spread response (LSR) in microvascular decompression (MVD) surgeries of hemifacial spasm (HFS). Methods A retrospective review was made of consecutive 25 patients who underwent continuous intraoperative monitoring during MVD. LSR and continuous electromyography were monitored in the frontalis, orbicularis oculi, and mentalis muscles. Extra-operative LSRs were done pre- and postoperatively. The neurological status of each patient was evaluated before and immediately after surgery, on discharge, and at 3 months after surgery. Results Intraoperative neurophysiologic monitorings were successful in all patients. On admission and discharge, extra-operative LSR recordings were done in 23 patients. Twenty-one patients completed a follow- up evaluation. In 17, the intraoperative LSRs disappeared during surgery. In 5, the intraoperative LSRs were absent before incision and remained the same until the end of surgery. In one, the intraoperative LSR were present before incision and persisted despite MVD. For extra-operative LSRs, they disappeared after surgery in 10. LSRs were absent before and after surgery in 7. In 6, LSRs were present before surgery and persisted after MVD. For 5, intraoperative LSRs disappeared during surgery but extra-operative LSRs were persisted despite adequate MVD. In one, intraoperative LSRs were absent before incision and remained during the surgery. But extra-operative LSRs were present before surgery and disappeared after adequate MVD. Statistically, the extra-operative disappearance of LSR was correlated with the HFS relief in 4 days after surgery and the 3-month follow up period. (P = 0.049 and 0.044). However, the intaroperative disapearance of LSR was not. Conclusion In our study, extra-operative LSR monitoring may be more predictive of the surgical outcome compared with intraoperative LSR during the 3-month follow up.

Introduction In the surgery of intramedullary spinal cord tumors (IMSCTs), risk of critical injury to motor and sensory pathways is higher due to direct tract manipulation. EMG provides immediate results without averaging during critical phases of the procedure. In this study, we evaluated whether combined use of EMG with SEP/MEP monitoring had any advantages over SEP/MEP monitoring. Methods The authors rewiewed clinical and neurophysiological data of the 25 operations in 21 patients with IMSCT. In these 21 patients, 12 were men and 9 were women; their median age was 41.05 years (range 26–83 years). We monitored SSEP, MEP and continuous free-running EMG during the surgery. Results Combined SEP/MEP/EMG monitoring was successfully performed in 14 of 25 operations. Combined SEP/MEP monitoring was done in 11 operations. New postoperative neurological deficits occurred in 15 operations: 5 had combined sensory and motor deficits, 9 had new sensory deficits, 1 had increased motor weakness. When we analyzed the accuracies, combined SEP/MEP monitoring had a sensitivity of 67%, a specificity of 60%, a positive predictive value (PPV) of 67%, and a negative predictive value (NPV) of 40%. Combined EMG/SEP/MEP monitoring had a sensitivity of 89%, a PPV of 62%. Conclusion Combined SEP/MEP/ EMG monitoring provided higher sensitivity than Combined SEP/MEP monitoring techniques in IMSCT surgery. Combined monitoring with SSEP/MEP and EMG can be more helpful for predicting neurological deficit in this surgery.

Limb-girdle muscular dystrophies (LGMD) are heterogeneous disorders with autosomal inheritance. Autosomal dominant LGMD mapped to 7q36.3 has been classified as LGMD type 1D (LGMD1D) in the Human Gene Nomenclature Committee Database. LGMD1D is characterized predominantly by limb-girdle weakness and may also show a bulbar symptom in some cases. In the past, the frequency of this disease was uncommon, and this disorder was mainly found in Europe and the United States. However, recently, this disorder has been reported in Asia, including Japan, Korea, and Taiwan. Here, we report on three LGMD1D patients, including one with a novel mutation in DNAJB6, c.298T>A. While two patients complained of limb-girdle weakness, as would be expected, one patient had distal weakness. They had various serum creatine kinase levels. Radiologic findings in one patient showed fatty degeneration and atrophy in the posterior part of distal muscles. Pathologic findings in one of the patients showed rimmed vacuoles. Although LGMD1D is still uncommon in Korea, we discovered three Korean patients with LGMD1D, including one novel mutation in DNAJB6, p.Phe100Ile (c.298T>A).

Background and Purpose Patients treated with interferon-beta (IFN-β) can develop neutralizing antibodies (NAbs) against IFN-β that can negatively affect the therapeutic response. This study assessed the prevalence of NAbs and the impact of NAb positivity on the therapeutic response to IFN-β in Korean patients with multiple sclerosis (MS). Methods This was a multicenter study involving 150 MS patients from 9 Korean medical centers who were treated with IFN-β for at least 6 months. Sera that had not been influenced by acute treatment were assessed for NAbs using a luciferase reporter gene assay. To evaluate the association between persistent positivity for NAbs and disease activity, NAbs were tested at 2 different time points in 75 of the 150 patients. Disease activity was defined as the presence of clinical exacerbations and/or active MRI lesions during a 1-year follow-up after NAb positivity was confirmed. Results NAbs were found in 39 of the 150 (26%) MS patients: 30 of the 85 (35%) who were treated with subcutaneous IFN-β-1b, 9 of the 60 (15%) who were treated with subcutaneous IFN-β-1a, and 0 of the 5 (0%) who were treated with intramuscular IFN-β-1a. Thirty of the 39 patients exhibiting NAb positivity were tested at different time points, and 20 of them exhibited persistent NAb positivity. Disease activity was observed more frequently in patients with persistent NAb positivity than in those with transient positivity or persistent negativity [16/20 (80%) vs. 4/55 (7%), respectively; p