The needle EMG findings in myotonia congenita

INTRODUCTION

Myotonia congenita (MC) is caused by pathogenic variants in the CLCN1 gene coding the chloride channel protein.

METHODS

To test the hypothesis that needle EMG could be helpful in distinguishing between the recessive and dominant MC, we performed EMG examination in 36 patients (23 men) aged 4-61 years with genetically proven MC: in 30 patients with autosomal recessive MC (Becker MC) and in 6 with autosomal dominant MC (Thomsen MC).

RESULTS

Myotonic discharges were recorded in 95.8% of examined muscles. For the whole MC group we observed a significant positive correlation between parameters of motor unit activity potentials (MUAPs) in vastus lateralis and tibialis anterior muscles and the duration of the disease. Similar correlation for biceps brachii also was found in Becker MC subgroup only.

DISCUSSION

EMG could still be helpful in diagnosis of MC and together with provocative tests might be useful in differentiation between recessive and autosomal MC.

Clinical Outcomes in Duchenne Muscular Dystrophy: A Study of 5345 Patients from the TREAT-NMD DMD Global Database

BACKGROUND

Recent short-term clinical trials in patients with Duchenne Muscular Dystrophy (DMD) have indicated greater disease variability in terms of progression than expected. In addition, as average life-expectancy increases, reliable data is required on clinical progression in the older DMD population.

OBJECTIVE

To determine the effects of corticosteroids on major clinical outcomes of DMD in a large multinational cohort of genetically confirmed DMD patients.

METHODS

In this cross-sectional study we analysed clinical data from 5345 genetically confirmed DMD patients from 31 countries held within the TREAT-NMD global DMD database. For analysis patients were categorised by corticosteroid background and further stratified by age.

RESULTS

Loss of ambulation in non-steroid treated patients was 10 years and in corticosteroid treated patients 13 years old (p = 0.0001). Corticosteroid treated patients were less likely to need scoliosis surgery (p < 0.001) or ventilatory support (p < 0.001) and there was a mild cardioprotective effect of corticosteroids in the patient population aged 20 years and older (p = 0.0035). Patients with a single deletion of exon 45 showed an increased survival in contrast to other single exon deletions.

CONCLUSIONS

This study provides data on clinical outcomes of DMD across many healthcare settings and including a sizeable cohort of older patients. Our data confirm the benefits of corticosteroid treatment on ambulation, need for scoliosis surgery, ventilation and, to a lesser extent, cardiomyopathy. This study underlines the importance of data collection via patient registries and the critical role of multi-centre collaboration in the rare disease field.

Long-term effect of thymectomy plus prednisone versus prednisone alone in patients with non-thymomatous myasthenia gravis: 2-year extension of the MGTX randomised trial

BACKGROUND

The Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone (MGTX) showed that thymectomy combined with prednisone was superior to prednisone alone in improving clinical status as measured by the Quantitative Myasthenia Gravis (QMG) score in patients with generalised non-thymomatous myasthenia gravis at 3 years. We investigated the long-term effects of thymectomy up to 5 years on clinical status, medication requirements, and adverse events.

METHODS

We did a rater-blinded 2-year extension study at 36 centres in 15 countries for all patients who completed the randomised controlled MGTX and were willing to participate. MGTX patients were aged 18 to 65 years at enrolment, had generalised non-thymomatous myasthenia gravis of less than 5 years' duration, had acetylcholine receptor antibody titres of 1·00 nmol/L or higher (or concentrations of 0·50-0·99 nmol/L if diagnosis was confirmed by positive edrophonium or abnormal repetitive nerve stimulation, or abnormal single fibre electromyography), had Myasthenia Gravis Foundation of America Clinical Classification Class II-IV disease, and were on optimal anticholinesterase therapy with or without oral corticosteroids. In MGTX, patients were randomly assigned (1:1) to either thymectomy plus prednisone or prednisone alone. All patients in both groups received oral prednisone at doses titrated up to 100 mg on alternate days until they achieved minimal manifestation status. The primary endpoints of the extension phase were the time-weighted means of the QMG score and alternate-day prednisone dose from month 0 to month 60. Analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00294658. It is closed to new participants, with follow-up completed.

FINDINGS

Of the 111 patients who completed the 3-year MGTX, 68 (61%) entered the extension study between Sept 1, 2009, and Aug 26, 2015 (33 in the prednisone alone group and 35 in the prednisone plus thymectomy group). 50 (74%) patients completed the 60-month assessment, 24 in the prednisone alone group and 26 in the prednisone plus thymectomy group. At 5 years, patients in the thymectomy plus prednisone group had significantly lower time-weighted mean QMG scores (5·47 [SD 3·87] vs 9·34 [5·08]; p=0·0007) and mean alternate-day prednisone doses (24 mg [SD 21] vs 48 mg [29]; p=0·0002) than did those in the prednisone alone group. 14 (42%) of 33 patients in the prednisone group, and 12 (34%) of 35 in the thymectomy plus prednisone group, had at least one adverse event by month 60. No treatment-related deaths were reported during the extension phase.

INTERPRETATION

At 5 years, thymectomy plus prednisone continues to confer benefits in patients with generalised non-thymomatous myasthenia gravis compared with prednisone alone. Although caution is appropriate when generalising our findings because of the small sample size of our study, they nevertheless provide further support for the benefits of thymectomy in patients with generalised non-thymomatous myasthenia gravis.

FUNDING

National Institutes of Health, National Institute of Neurological Disorders and Stroke.

High incidence and clinical characteristics of fibromuscular dysplasia in patients with spontaneous cervical artery dissection: The ARCADIA-POL study

The association between fibromuscular dysplasia (FMD) and spontaneous cervical artery dissection (SCeAD) has been recognized, but the available evidence on this relationship is scant. Therefore, the main goal of our study was to systematically evaluate FMD frequency, clinical characteristics and vascular bed involvement in patients with SCeAD. Among 230 patients referred to the ARCADIA-POL study, 43 patients (mean age 44.1 ± 8.9 years; 15 men and 28 women) with SCeAD were referred. Also, 135 patients with FMD were compared to patients with and without SCeAD. Patients underwent: ambulatory blood pressure measurements, biochemical evaluation, echocardiographic examination, and whole body computed tomographic angiography. FMD changes were found in 39.5% of patients with SCeAD. There were no differences in clinical characteristics between patients with SCeAD and FMD and those without FMD, except for a tendency towards a higher female ratio in SCeAD patients with FMD. There were no differences in other parameters describing target organ and SCeAD characteristics. Patients with SCeAD and FMD compared to those without SCeAD were characterized by a lower frequency of hypertension and a higher frequency of hyperlipidemia and history of contraceptive hormone use. Our study indicates a high incidence (39.5%) of FMD in subjects with SCeAD. Since there are no distinctive discriminating factors between patients with SCeAD and FMD and those without FMD, FMD should be suspected in all patients with SCeAD.

Eight years after an international workshop on myotonic dystrophy patient registries: case study of a global collaboration for a rare disease

BACKGROUND

Myotonic Dystrophy is the most common form of muscular dystrophy in adults, affecting an estimated 10 per 100,000 people. It is a multisystemic disorder affecting multiple generations with increasing severity. There are currently no licenced therapies to reverse, slow down or cure its symptoms. In 2009 TREAT-NMD (a global alliance with the mission of improving trial readiness for neuromuscular diseases) and the Marigold Foundation held a workshop of key opinion leaders to agree a minimal dataset for patient registries in myotonic dystrophy. Eight years after this workshop, we surveyed 22 registries collecting information on myotonic dystrophy patients to assess the proliferation and utility the dataset agreed in 2009. These registries represent over 10,000 myotonic dystrophy patients worldwide (Europe, North America, Asia and Oceania).

RESULTS

The registries use a variety of data collection methods (e.g. online patient surveys or clinician led) and have a variety of budgets (from being run by volunteers to annual budgets over €200,000). All registries collect at least some of the originally agreed data items, and a number of additional items have been suggested in particular items on cognitive impact.

CONCLUSIONS

The community should consider how to maximise this collective resource in future therapeutic programmes.

Heme Oxygenase-1 Influences Satellite Cells and Progression of Duchenne Muscular Dystrophy in Mice

AIMS

Muscle damage in Duchenne muscular dystrophy (DMD) caused by the lack of dystrophin is strongly linked to inflammation. Heme oxygenase-1 (HO-1; Hmox1) is an anti-inflammatory and cytoprotective enzyme affecting myoblast differentiation by inhibiting myomiRs. The role of HO-1 has not been so far well addressed in DMD.

RESULTS

In dystrophin-deficient mdx mice, expression of Hmox1 in limb skeletal muscles and diaphragm is higher than in wild-type animals, being consistently elevated from 8 up to 52 weeks, both in myofibers and inflammatory leukocytes. Accordingly, HO-1 expression is induced in muscles of DMD patients. Pharmacological inhibition of HO-1 activity or genetic ablation of Hmox1 aggravates muscle damage and inflammation in mdx mice. Double knockout animals (Hmox1^-/-mdx) demonstrate impaired exercise capacity in comparison with mdx mice. Interestingly, in contrast to the effect observed in muscle fibers, in dystrophin-deficient muscle satellite cells (SCs) expression of Hmox1 is decreased, while MyoD, myogenin, and miR-206 are upregulated compared with wild-type counterparts. Mdx SCs demonstrate disturbed and enhanced differentiation, which is further intensified by Hmox1 deficiency. RNA sequencing revealed downregulation of Atf3, MafK, Foxo1, and Klf2 transcription factors, known to activate Hmox1 expression, as well as attenuation of nitric oxide-mediated cGMP-dependent signaling in mdx SCs. Accordingly, treatment with NO-donor induces Hmox1 expression and inhibits differentiation. Finally, differentiation of mdx SCs was normalized by CO, a product of HO-1 activity. Innovation and Conclusions: HO-1 is induced in DMD, and HO-1 inhibition aggravates DMD pathology. Therefore, HO-1 can be considered a therapeutic target to alleviate this disease. Antioxid. Redox Signal. 00, 000-000.

WITHDRAWN: Evidence for a relatively high proportion of DM2 mutations in a large group of Polish patients

The Publisher regrets that this article is an accidental duplication of an article that has already been published, 10.1016/j.pjnns.2018.02.008. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Serum interleukin 15 levels in patients with seropositive myasthenia gravis do not correlate with disease severity

AIM

To assess interleukin 15 (IL-15) serum levels in patients with seropositive myasthenia gravis (MG); searching for potential relationship between IL-15 levels and clinical features such as gender, age at onset, clinical presentation or treatment received.

BACKGROUND

IL-15 plays pivotal role in T-cell dependent autoimmunity. Increased IL-15 serum levels have been reported in several autoimmune diseases including MG patients from Japan.

PATIENTS AND METHODS

Sera of 42 seropositive MG patients (66.7% women), mean age 50.6±23.7 years) have been tested by ELISA for IL-15 levels.

RESULTS

There were no statistically significant differences between IL-15 serum levels in MG patients in comparison with controls as well as between subgroups of MG patients (early vs. late onset and thymoma MG). Mean/median IL-15 serum levels were similar in MG patients treated with corticosteroids (CS) and CS naïve. Outliers (very high values) were seen only in untreated generalized MG patients.

CONCLUSIONS

Serum interleukin 15 levels in patients with seropositive myasthenia gravis do not correlate with disease severity.

Evidence for a relatively high proportion of DM2 mutations in a large group of Polish patients

INTRODUCTION

Myotonic dystrophies (DMs) type 1 (DM1) and type 2 (DM2) are autosomal dominant, multisystem disorders, considered the most common dystrophies in adults. DM1 and DM2 are caused by dynamic mutations in the DMPK and CNBP genes, respectively.

METHODS

Molecular analyses were performed by PCR and the modified RP-PCR in patients, in their at-risk relatives and prenatal cases.

RESULTS

The analysis of Polish controls revealed the range of 5-31 CTG repeats for DM1 and 110-228 bp alleles for DM2. Among 318 confirmed probands - 196 (62%) were DM1 and 122 (38%) - DM2. Within DM1families, 10 subjects carried a low expanded CTG tract (< 100 repeats), which resulted in a full mutation in subsequent generations. Two related individuals had unstable alleles-188 bp and 196 bp without common interruptions.

CONCLUSION

The relative frequencies of DM1/DM2 among Polish patients were 68% and 32%, respectively, with a relatively high proportion of DM2 mutations (1.6:1).

European Cross-Sectional Survey of Current Care Practices for Duchenne Muscular Dystrophy Reveals Regional and Age-Dependent Differences

Background: Publication of comprehensive clinical care guidelines for Duchenne muscular dystrophy (DMD) in 2010 was a milestone for DMD patient management. Our CARE-NMD survey investigates the neuromuscular, medical, and psychosocial care of DMD patients in Europe, and compares it to the guidelines.

Methods: A cross-sectional survey of 1677 patients contacted via the TREAT-NMD patient registries was conducted using self-report questionnaires in seven European countries.

Results: Survey respondents were 861 children and 201 adults. Data describe a European DMD population with mean age of 13.0 years (range 0.8–46.2) of whom 53% had lost ambulation (at 10.3 years of age, median). Corticosteroid medication raised the median age for ambulatory loss from 10.1 years in patients never medicated to 11.4 years in patients who received steroids (p < 0.0001). The majority of patients reported receiving care in line with guidelines, although we identified significant differences between countries and important shortcomings in prevention and treatment. Summarised, 35% of patients aged≥ nine years received no corticosteroid medication, 24% of all patients received no regular physiotherapy, echocardiograms were not performed regularly in 22% of patients, pulmonary function was not regularly assessed in 71% of non-ambulatory patients. Patients with regular follow-up by neuromuscular specialists were more likely to receive care according to guidelines, were better satisfied, and experienced shorter unplanned hospitalization periods.

Identification of GAA variants through whole exome sequencing targeted to a cohort of 606 patients with unexplained limb-girdle muscle weakness

Background

Late-onset Pompe disease is a rare genetic neuromuscular disorder caused by a primary deficiency of α-glucosidase and the associated accumulation of glycogen in lysosomal vacuoles. The deficiency of α-glucosidase can often be detected using an inexpensive and readily accessible dried blood spot test when Pompe disease is suspected. Like several neuromuscular disorders, Pompe disease typically presents with progressive weakness of limb-girdle muscles and respiratory insufficiency. Due to the phenotypic heterogeneity of these disorders, however, it is often difficult for clinicians to reach a diagnosis for patients with Pompe disease. Six hundred and six patients from a European population were recruited onto our study. Inclusion criteria stipulated that index cases must present with limb-girdle weakness or elevated serum creatine kinase activity. Whole exome sequencing with at least 250 ng DNA was completed using an Illumina exome capture and a 38 Mb baited target. A panel of 169 candidate genes for limb-girdle weakness was analysed for disease-causing variants.

Results

A total of 35 variants within GAA were detected. Ten distinct variants in eight unrelated index cases (and four siblings not sequenced in our study) were considered disease-causing, with the patients presenting with heterogeneous phenotypes. The eight unrelated individuals were compound heterozygotes for two variants. Six patients carried the intronic splice site c.-13 T > G transversion and two of the six patients also carried the exonic p.Glu176ArgfsTer45 frameshift. Four of the ten variants were novel in their association with Pompe disease.

Conclusions

Here, we highlight the advantage of using whole exome sequencing as a tool for detecting, diagnosing and treating patients with rare, clinically variable genetic disorders.

Mechanical thrombectomy in acute stroke - Five years of experience in Poland

OBJECTIVES

Mechanical thrombectomy (MT) is not reimbursed by the Polish public health system. We present a description of 5 years of experience with MT in acute stroke in Comprehensive Stroke Centers (CSCs) in Poland.

METHODS AND RESULTS

We retrospectively analyzed the results of a structured questionnaire from 23 out of 25 identified CSCs and 22 data sets that include 61 clinical, radiological and outcome measures.

RESULTS

Most of the CSCs (74%) were founded at University Hospitals and most (65.2%) work round the clock. In 78.3% of them, the working teams are composed of neurologists and neuro-radiologists. All CSCs perform CT and angio-CT before MT. In total 586 patients were subjected to MT and data from 531 of them were analyzed. Mean time laps from stroke onset to groin puncture was 250±99min. 90.3% of the studied patients had MT within 6h from stroke onset; 59.3% of them were treated with IV rt-PA prior to MT; 15.1% had IA rt-PA during MT and 4.7% - emergent stenting of a large vessel. M1 of MCA was occluded in 47.8% of cases. The Solitaire device was used in 53% of cases. Successful recanalization (TICI2b-TICI3) was achieved in 64.6% of cases and 53.4% of patients did not experience hemorrhagic transformation. Clinical improvement on discharge was noticed in 53.7% of cases, futile recanalization - in 30.7%, mRS of 0-2 - in 31.4% and mRS of 6 in 22% of cases.

CONCLUSION

Our results can help harmonize standards for MT in Poland according to international guidelines.

Abnormal spontaneous activity in primary myopathic disorders

INTRODUCTION

Reproducible non-insertional spontaneous activity (SA), with the exception of endplate activity, is an unequivocal sign of abnormality and is one of the most useful findings obtained on electromyography.

METHODS

In this retrospective study we analyzed occurrence and distribution of abnormal SA in 151 patients with genetically confirmed myopathies.

RESULTS

Complex repetitive discharges (CRDs) occurred more frequently than fibrillation potentials (fibs) and positive sharp waves (PSWs) in centronuclear myopathy (CNM) and limb-girdle muscular dystrophy type 2A (LGMD-2A), whereas fibs/PSWs were observed more often in desminopathy and facioscapulohumeral dystrophy (FSHD). Abnormal SA was commonly found in CNM (66.7%) and desminopathy (61.5%), occasionally in Duchenne (DMD) and Becker muscular dystrophy (BMD) (45.2% and 27.6%, respectively), but rarely in FSHD (14.9%) and LGMD-2A (12.0%).

CONCLUSIONS

Abnormal SA probably occurs more frequently in disorders associated with structural changes in muscle fibers. Screening for SA may be a valuable tool for diagnosis of non-myotonic myopathies. Muscle Nerve 56: 427-432, 2017.