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INTRODUCTION/AIMS: Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive muscular dystrophy without approved therapies. In this study we evaluated whether locally acting ACE-083 could safely increase muscle volume and improve functional outcomes in adults with FSHD. METHODS: Participants were at least 18 years old and had FSHD1/FSHD2. Part 1 was open label, ascending dose, assessing safety and tolerability (primary objective). Part 2 was randomized, double-blind for 6 months, evaluating ACE-083240 mg/muscle vs placebo injected bilaterally every 3 weeks in the biceps brachii (BB) or tibialis anterior (TA) muscles, followed by 6 months of open label. Magnetic resonance imaging measures included total muscle volume (TMV; primary objective), fat fraction (FF), and contractile muscle volume (CMV). Functional measures included 6-minute walk test, 10-meter walk/run, and 4-stair climb (TA group), and performance of upper limb midlevel/elbow score (BB group). Strength, patient-reported outcomes (PROs), and safety were also evaluated. RESULTS: Parts 1 and 2 enrolled 37 and 58 participants, respectively. Among 55 participants evaluable in Part 2, the least-squares mean (90% confidence interval, analysis of covariance) treatment difference for TMV was 16.4% (9.8%-23.0%) in the BB group (P < .0001) and 9.5% (3.2%-15.9%) in the TA group (P = .01). CMV increased significantly in the BB and TA groups and FF decreased in the TA group. There were no consistent improvements in functional or PRO measures in either group. The most common adverse events were mild or moderate injection-site reactions. DISCUSSION: Significant increases in TMV with ACE-083 vs placebo did not result in consistent functional or PRO improvements with up to 12 months of treatment.

This study determined the frequency and impact of symptoms on quality of life (QoL) in patients diagnosed with limb girdle muscular dystrophy (LGMD). Participants with a diagnosis of LGMD in registries based at the Coalition to Cure Calpain-3, the Jain foundation, and the Global FKRP Registry competed a survey to report the frequency and relative impact of themes and symptoms of LGMD. Frequency, mean impact, and population impact scores were calculated, and responses were categorized by age, symptom duration, gender, employment status, use of assistive devices, and LGMD subtypes. 134 participants completed the survey. The most prevalent themes included an inability to do activities (100%), limitation with mobility (99.3%), and lower extremity weakness (97.0%). Themes with the greatest impact were: limitations with mobility, lower extremity weakness, and an inability to do activities. Symptom duration and the use of assistive devices were associated with the presence of multiple themes. Employment was associated with the impact of several themes with no differences in frequency. The prevalence and impact of these themes vary in the LMGD population. The most prevalent and impactful themes were related to weakness, but additional concerns related to emotional challenges should also be considered in clinical and research settings.

Introduction Limb-girdle muscular dystrophy (LGMD) consists of over 30 genetic conditions with varying clinical phenotypes primarily affecting pelvic girdle, shoulder girdle, and other proximal limb muscles. Studies focusing on the physical, mental, and social effects of this disease from the patient's perspective are limited. Methods Adults with LGMD were interviewed and asked to identify issues that have the greatest impact on their quality of life. Each interview was recorded, transcribed, coded, and analyzed. Results Participants provided 1385 direct quotes. One hundred sixty-five potential symptoms of importance were identified and grouped into 15 larger themes. The most frequently reported themes included limitations with mobility, difficulty performing activities, social role limitations, and emotional distress. Discussion There are multiple symptoms that alter the lives of adults with LGMD. These affect their physical, emotional, and social health, and may be amenable to medical intervention.

Background and Objectives We investigated the prevalence of late-onset Pompe disease (LOPD) in patients presenting to 13 academic, tertiary neuromuscular practices in the United States and Canada. Methods All successive patients presenting with proximal muscle weakness or isolated hyperCKemia and/or neck muscle weakness to these 13 centers were invited to participate in the study. Whole blood was tested for acid alpha-glucosidase (GAA) assay through the fluorometric method, and all cases with enzyme levels of ≤10 pmoL/punch/h were reflexed to molecular testing for mutations in the GAA gene. Clinical and demographic information was abstracted from their clinical visit and, along with study data, entered into a purpose-built REDCap database, and analyzed at the University of California, Irvine. Results GAA enzyme assay results were available on 906 of the 921 participants who consented for the study. LOPD was confirmed in 9 participants (1% prevalence). Another 9 (1%) were determined to have pseudodeficiency of GAA, whereas 19 (1.9%) were found to be heterozygous for a pathogenic GAA mutation (carriers). Of the definite LOPD participants, 8 (89%) were Caucasian and were heterozygous for the common leaky (IVS1) splice site mutation in the GAA gene (c -32-13T>G), with a second mutation that was previously confirmed to be pathogenic. Discussion The prevalence of LOPD in undiagnosed patients meeting the criteria of proximal muscle weakness, high creatine kinase, and/or neck weakness in academic, tertiary neuromuscular practices in the United States and Canada is estimated to be 1%, with an equal prevalence rate of pseudodeficiency alleles. Trial Registration Information Clinical trial registration number: NCT02838368.

The limb girdle muscular dystrophies (LGMDs) are genetic muscle diseases with primary skeletal muscle involvement in persons with the ability to walk independently at some point in the disease course. They usually have increased creatine kinase levels along with patterns of fatty and fibrous deposition on muscle imaging and/or dystrophic features on muscle biopsy. Distinctive clinical features provide valuable diagnostic clues to the diagnosis and sometimes treatment of these disorders. The advent of gene and cell-based therapies; gene replacement, editing, and modulation; along with stem cell and small molecule therapies may significantly ameliorate clinical severity in the LGMDs.

Author(s): Nallamilli, Babi Ramesh Reddy; Chakravorty, Samya; Kesari, Akanchha; Tanner, Alice; Ankala, Arunkanth; Schneider, Thomas; da Silva, Cristina; Beadling, Randall; Alexander, John J; Askree, Syed Hussain; Whitt, Zachary; Bean, Lora; Collins, Christin; Khadilkar, Satish; Gaitonde, Pradnya; Dastur, Rashna; Wicklund, Matthew; Mozaffar, Tahseen; Harms, Matthew; Rufibach, Laura; Mittal, Plavi; Hegde, Madhuri | Abstract: ObjectiveLimb-girdle muscular dystrophies (LGMDs), one of the most heterogeneous neuromuscular disorders (NMDs), involves predominantly proximal-muscle weakness with g30 genes associated with different subtypes. The clinical-genetic overlap among subtypes and with other NMDs complicate disease-subtype identification lengthening diagnostic process, increases overall costs hindering treatment/clinical-trial recruitment. Currently seven LGMD clinical trials are active but still no gene-therapy-related treatment is available. Till-date no nation-wide large-scale LGMD sequencing program was performed. Our objectives were to understand LGMD genetic basis, different subtypes' relative prevalence across US and investigate underlying disease mechanisms.MethodsA total of 4656 patients with clinically suspected-LGMD across US were recruited to conduct next-generation sequencing (NGS)-based gene-panel testing during June-2015 to June-2017 in CLIA-CAP-certified Emory-Genetics-Laboratory. Thirty-five LGMD-subtypes-associated or LGMD-like other NMD-associated genes were investigated. Main outcomes were diagnostic yield, gene-variant spectrum, and LGMD subtypes' prevalence in a large US LGMD-suspected population.ResultsMolecular diagnosis was established in 27% (1259 cases; 95% CI, 26-29%) of the patients with major contributing genes to LGMD phenotypes being: CAPN3(17%), DYSF(16%), FKRP(9%) and ANO5(7%). We observed an increased prevalence of genetically confirmed late-onset Pompe disease, DNAJB6-associated LGMD subtype1E and CAPN3-associated autosomal-dominant LGMDs. Interestingly, we identified a high prevalence of patients with pathogenic variants in more than one LGMD gene suggesting possible synergistic heterozygosity/digenic/multigenic contribution to disease presentation/progression that needs consideration as a part of diagnostic modality.InterpretationOverall, this study has improved our understanding of the relative prevalence of different LGMD subtypes, their respective genetic etiology, and the changing paradigm of their inheritance modes and novel mechanisms that will allow for improved timely treatment, management, and enrolment of molecularly diagnosed individuals in clinical trials.

Uncovering the mechanistic link between kinesin motors and neuropathy, Xu et al. identify functional KIF1Bβ mutations in human hereditary neuropathy to analyze them in mouse models. They propose that KIF1Bβ transports IGF1R and facilitates axonal outgrowth. Both of these effects are significantly affected by the clinical mutations., KIF1Bβ is a kinesin-3 family anterograde motor protein essential for neuronal development, viability, and function. KIF1Bβ mutations have previously been reported in a limited number of pedigrees of Charcot-Marie-Tooth disease type 2A (CMT2A) neuropathy. However, the gene responsible for CMT2A is still controversial, and the mechanism of pathogenesis remains elusive. In this study, we show that the receptor tyrosine kinase IGF1R is a new direct binding partner of KIF1Bβ, and its binding and transport is specifically impaired by the Y1087C mutation of KIF1Bβ, which we detected in hereditary neuropathic patients. The axonal outgrowth and IGF-I signaling of Kif1b−/− neurons were significantly impaired, consistent with decreased surface IGF1R expression. The complementary capacity of KIF1Bβ-Y1087C of these phenotypes was significantly impaired, but the binding capacity to synaptic vesicle precursors was not affected. These data have supported the relevance of KIF1Bβ in IGF1R transport, which may give new clue to the neuropathic pathogenesis.

Objective. This study determined acute and long-term effects of propofol administration in patients with severe headaches undergoing endoscopic procedures. Background. Approximately 13% of the US population is affected by migraines or severe headaches. The effect of propofol on headaches more than a few days after the intervention has not been explored. Methods. We employed a nonrandomized, prospective observational study that recruited patients with chronic headaches who received propofol from an outpatient endoscopy center for either upper or lower endoscopies. Patients completed the six-item Headache Impact Test (HIT-6) questionnaire prior to the procedure and 30 days after endoscopy. Additionally, the patients’ response to propofol two days after endoscopy was assessed via phone. Results. The age of the participants (n=31) ranged from 20 to 70 years. The mean HIT-6 composite scores were significantly lower (p<0.05) 30 days after propofol administration when compared to baseline scores. Upon stratification, 23 patients indicated an improved condition, 7 a worsened outcome, and 1 showed no change. Furthermore, mean scores were significantly lower (p<0.05) in three HIT-6 questions pertaining to the severity of pain, daily activity, and frequency of lying down. Finally, the mean pain score obtained was significantly lower (p<0.05) two days after procedure. Conclusions. The results of this suggest that propofol administration should be considered in treating chronic headaches. Double-blind studies are necessary to confirm these results.

Objective: Reporting a novel mutation in the HTRA1 gene in a CARASIL patient from Americas. Methods: Clinical presentation and neuroimaging were consistent with CARASIL. HTRA1 DNA sequencing was performed using advanced (“next generation”) sequencing technology. The results revealed a homozygous missense mutation as c.616G>A (p.Gly206Arg) in the HTRA1 gene. Results: A 24-year-old man with a history of chronic back pain presented with recurrent ischemic strokes. A diagnosis of CARASIL was made with the finding of a novel homozygous missense mutation c.616G>A in HTRA1 gene, resulting in change from Glycine to Arginine in the Serine Protease HTRA1. Brain imaging showed multiple lacunar infarcts with extensive abnormalities of the white matter that spared the external capsules. He also had unilateral decreased hearing with craniofacial asymmetry. None of the above features have been previously described in known CARASIL patients. Both parents of the proband were heterozygous for the same missense mutation. Conclusion: We discovered a novel missense mutation (c.616G>A) associated with a phenotype of CARASIL. This is the first genetically backed case of CARASIL in the new world. The patient's craniofacial abnormalities, including asymmetry of the head, may be related to impaired modulation of transforming growth factor-β1, the result of loss of proteolytic activity of HTRA1. External capsules remained unaffected, despite findings of advanced changes in the rest of the cerebral white matter. Literature is briefly reviewed. The patient's history, neurological exam, neuroimaging, and genetic testing are included.

Purpose of review As a group, the limb-girdle muscular dystrophies (LGMDs) are the fourth most prevalent genetic muscle disease, yet they are still not well known or understood. This article defines and describes LGMDs, delineates a diagnostic strategy, and discusses treatment of the LGMDs. Recent findings In 2018, the definition of the LGMDs was further refined, and a new nomenclature was proposed. Diagnosis of the LGMDs was long guided by the distinctive clinical characteristics of each particular subtype but now integrates use of genetics-with next-generation sequencing panels, exomes, and full genome analysis-early in the diagnostic assessment. Appreciation of the phenotypic diversity of each LGMD subtype continues to expand. This emphasizes the need for precision genetic diagnostics to better understand each subtype and formulate appropriate management for individual patients. Of significant relevance, the explosion of research into therapeutic options accentuates the need for accurate diagnosis, comprehensive disease characterization, and description of the natural histories of the LGMDs to move the field forward and to mitigate disease impact on patients with LGMD. Summary The LGMDs are genetic muscle diseases that superficially appear similar to one another but have important differences in rates of progression and concomitant comorbidities. Definitive diagnoses are crucial to guide management and treatment now and in the future. As targeted treatments emerge, it will be important for clinicians to understand the nomenclature, diagnosis, clinical manifestations, and treatments of the LGMDs.

INTRODUCTION The utility of repeat muscle biopsy has not been adequately evaluated. METHODS A retrospective review was undertaken of 144 repeat muscle biopsies performed from 1980 to 2017. Repeat biopsy was considered clinically relevant if it provided a new diagnosis, changed the existing diagnosis, or led to treatment changes or further investigations. RESULTS Repeat biopsy was abnormal in 118 cases, different from the initial biopsy in 67 cases, and specific in 40 cases. Factors with a significant effect on clinical relevance of the repeat biopsy (P < 0.05) were an abnormal, specific, or inflammatory initial biopsy, proximal muscle weakness, absence of myalgia, and a repeat biopsy that is different, specific, or consistent with polymyositis or inclusion body myositis. CONCLUSIONS Utility of repeat biopsy was limited to weak patients whose initial biopsy showed inflammatory myositis. Ongoing advances in the diagnosis of immune inflammatory myopathies have led to evolution of the role of repeat biopsy. Muscle Nerve, 2019.

ObjectiveTo describe novel clinical features of GlyRα1-IgG–positive patients.MethodsPatients with a positive serum GlyRα1-IgG were identified during a 2-year period from July 2016 to December 2018 at 2 academic centers and followed prospectively. All patients in this series were evaluated in the Neuroimmunology and Autoimmune Neurology clinics at the University of Utah or the University of Colorado.ResultsThirteen of 17 patients had phenotypes more typically associated with glutamic acid decarboxylase (GAD65) antibody syndromes, consisting of stiff-person syndrome (SPS) with parkinsonism or cerebellar signs. One patient with parkinsonism had a presentation similar to rapidly progressive multiple system atrophy with severe dysautonomia. Ten of 17 patients had various visual symptoms including visual snow, spider web–like images forming shapes and 3-dimensional images, palinopsia, photophobia, visual hallucinations, synesthesia, and intermittent diplopia. Three of 17 patients presented with primarily autoimmune epilepsy accompanied by psychiatric symptoms.ConclusionsClinicians should consider testing for GlyR antibodies in GAD65 antibody–negative or low-positive GAD65 antibody patients with SPS-like presentations, especially in the setting of atypical features such as visual disturbances, parkinsonism, or epilepsy.

Importance Cryptogenic sensory polyneuropathy (CSPN) is a common generalized slowly progressive neuropathy, second in prevalence only to diabetic neuropathy. Most patients with CSPN have significant pain. Many medications have been tried for pain reduction in CSPN, including antiepileptics, antidepressants, and sodium channel blockers. There are no comparative studies that identify the most effective medication for pain reduction in CSPN. Objective To determine which medication (pregabalin, duloxetine, nortriptyline, or mexiletine) is most effective for reducing neuropathic pain and best tolerated in patients with CSPN. Design, Setting, and Participants From December 1, 2014, through October 20, 2017, a bayesian adaptive, open-label randomized clinical comparative effectiveness study of pain in 402 participants with CSPN was conducted at 40 neurology care clinics. The trial included response adaptive randomization. Participants were patients with CSPN who were 30 years or older, with a pain score of 4 or greater on a numerical rating scale (range, 0-10, with higher scores indicating a higher level of pain). Participant allocation to 1 of 4 drug groups used the utility function and treatment’s sample size for response adaptation randomization. At each interim analysis, a decision was made to continue enrolling (up to 400 participants) or stop the whole trial for success (80% power). Patient engagement was maintained throughout the trial, which helped guide the study and identify ways to communicate and disseminate information. Analysis was performed from December 11, 2015, to January 19, 2018. Interventions Participants were randomized to receive nortriptyline (n = 134), duloxetine (n = 126), pregabalin (n = 73), or mexiletine (n = 69). Main Outcomes and Measures The primary outcome was a utility function that was a composite of the efficacy (participant reported pain reduction of ≥50% from baseline to week 12) and quit (participants who discontinued medication) rates. Results Among the 402 participants (213 men [53.0%]; mean [SD] age, 60.1 [13.4] years; 343 White [85.3%]), the utility function of nortriptyline was 0.81 (95% bayesian credible interval [CrI], 0.69-0.93; 34 of 134 [25.4%] efficacious; and 51 of 134 [38.1%] quit), of duloxetine was 0.80 (95% CrI, 0.68-0.92; 29 of 126 [23.0%] efficacious; and 47 of 126 [37.3%] quit), pregabalin was 0.69 (95% CrI, 0.55-0.84; 11 of 73 [15.1%] efficacious; and 31 of 73 [42.5%] quit), and mexiletine was 0.58 (95% CrI, 0.42-0.75; 14 of 69 [20.3%] efficacious; and 40 of 69 [58.0%] quit). The probability each medication yielded the highest utility was 0.52 for nortriptyline, 0.43 for duloxetine, 0.05 for pregabalin, and 0.00 for mexiletine. Conclusions and Relevance This study found that, although there was no clearly superior medication, nortriptyline and duloxetine outperformed pregabalin and mexiletine when pain reduction and undesirable adverse effects are combined to a single end point. Trial Registration ClinicalTrials.gov Identifier:NCT02260388

Objective: To determine the steroid-sparing effect of methotrexate (MTX) in patients with symptomatic generalized myasthenia gravis (MG). Methods: We performed a 12-month multicenter, randomized, double-blind, placebo-controlled trial of MTX 20 mg orally every week vs placebo in 50 acetylcholine receptor antibody–positive patients with MG between April 2009 and August 2014. The primary outcome measure was the prednisone area under the dose-time curve (AUDTC) from months 4 to 12. Secondary outcome measures included 12-month changes of the Quantitative Myasthenia Gravis Score, the Myasthenia Gravis Composite Score, Manual Muscle Testing, the Myasthenia Gravis Quality of Life, and the Myasthenia Gravis Activities of Daily Living. Results: Fifty-eight patients were screened and 50 enrolled. MTX did not reduce the month 4–12 prednisone AUDTC when compared to placebo (difference MTX − placebo: −488.0 mg, 95% confidence interval −2,443.4 to 1,467.3, p = 0.26); however, the average daily prednisone dose decreased in both groups. MTX did not improve secondary measures of MG compared to placebo over 12 months. Eight participants withdrew during the course of the study (1 MTX, 7 placebo). There were no serious MTX-related adverse events. The most common adverse event was nonspecific pain (19%). Conclusions: We found no steroid-sparing benefit of MTX in MG over 12 months of treatment, despite being well-tolerated. This study demonstrates the challenges of conducting clinical trials in MG, including difficulties with recruitment, participants improving on prednisone alone, and the need for a better understanding of outcome measure variability for future clinical trials. Classification of evidence: This study provides Class I evidence that for patients with generalized MG MTX does not significantly reduce the prednisone AUDTC over 12 months of therapy.

The sarcoglycanopathies are a heterogeneous group of autosomal recessive limb-girdle muscular dystrophies that cause varying degrees of progressive proximal muscle weakness.We describe the case of a Caucasian girl who presented with exercise intolerance, myalgia, and dark urine. Onset of symptoms was at age 4, and she had myalgia with physical activity throughout childhood. Creatine kinase levels were as high as 18,000.Immunostaining of a muscle biopsy showed mildly diminished alpha sarcoglycan staining, and SGCA gene sequencing revealed n.C229T; p.Arg77Cys (R77C) and n.C850T; p.Arg284Cys (R284C), which is associated with alpha sarcoglycanopathy.This patient presented with exercise intolerance, myoglobinuria, and almost normal muscle strength into adolescence, which is uncommon in sarcoglycanopathies. This uncommon presentation should be kept in mind, so that early recognition and intervention may prevent future comorbidities and help preserve the quality of life. Muscle Nerve 54: 161-164, 2016.

Background Trials in rare diseases have many challenges, among which are the need to set up multiple sites in different countries to achieve recruitment targets and the divergent landscape of clinical trial regulations in those countries. Over the past years, there have been initiatives to facilitate the process of international study set-up, but the fruits of these deliberations require time to be operationally in place. FOR-DMD (Finding the Optimum Steroid Regimen for Duchenne Muscular Dystrophy) is an academic-led clinical trial which aims to find the optimum steroid regimen for Duchenne muscular dystrophy, funded by the National Institutes of Health (NIH) for 5 years (July 2010 to June 2015), anticipating that all sites (40 across the USA, Canada, the UK, Germany and Italy) would be open to recruitment from July 2011. However, study start-up was significantly delayed and recruitment did not start until January 2013. Method The FOR-DMD study is used as an example to identify systematic problems in the set-up of international, multi-centre clinical trials. The full timeline of the FOR-DMD study, from funding approval to site activation, was collated and reviewed. Systematic issues were identified and grouped into (1) study set-up, e.g. drug procurement; (2) country set-up, e.g. competent authority applications; and (3) site set-up, e.g. contracts, to identify the main causes of delay and suggest areas where anticipatory action could overcome these obstacles in future studies. Results Time from the first contact to site activation across countries ranged from 6 to 24 months. Reasons of delay were universal (sponsor agreement, drug procurement, budgetary constraints), country specific (complexity and diversity of regulatory processes, indemnity requirements) and site specific (contracting and approvals). The main identified obstacles included (1) issues related to drug supply, (2) NIH requirements regarding contracting with non-US sites, (3) differing regulatory requirements in the five participating countries, (4) lack of national harmonisation with contracting and the requirement to negotiate terms and contract individually with each site and (5) diversity of languages needed for study materials. Additionally, as with many academic-led studies, the FOR-DMD study did not have access to the infrastructure and expertise that a contracted research organisation could provide, organisations often employed in pharmaceutical-sponsored studies. This delay impacted recruitment, challenged the clinical relevance of the study outcomes and potentially delayed the delivery of the best treatment to patients. Conclusion Based on the FOR-DMD experience, and as an interim solution, we have devised a checklist of steps to not only anticipate and minimise delays in academic international trial initiation but also identify obstacles that will require a concerted effort on the part of many stakeholders to mitigate.

Charcot-Marie-Tooth disease (CMT), also known as hereditary motor sensory neuropathy, is a heterogeneous group of disorders best known for causing inherited forms of peripheral neuropathy. The X-linked form, CMTX1, is caused by mutations in the gap junction protein beta 1 (GJB1) gene, expressed both by peripheral Schwann cells and central oligodendrocytes. Central manifestations are known but are rare, and there are few case reports of leukoencephalopathy with transient or persistent neurological deficits in patients with this CMT subtype. Here, we report the case of a man with multiple male and female family members affected by neuropathy who carries a pathologic mutation in GJB1. He has experienced three transient episodes with variable neurological deficits over the course of 7 years with corresponding changes on magnetic resonance imaging (MRI). This case illustrates CMT1X as a rare cause of transient neurological deficit and demonstrates the evolution of associated reversible abnormalities on MRI over time. To the best of our knowledge, this report provides the longest period of serial imaging in a single patient with this condition in the English language literature.

In myotonic dystrophy type 2 (DM2), an association has been reported between early and severe myotonia and recessive chloride channel (. CLCN1) mutations. No DM2 cases have been described with sodium channel gene (. SCN4A) mutations. The aim is to describe a DM2 patient with severe and early onset myotonia and co-occurrence of a novel missense mutation in SNC4A. A 26-year-old patient complaining of hand cramps and difficulty relaxing her hands after activity was evaluated at our department. Neurophysiology and genetic analysis for DM1, DM2, CLCN1 and SCN4A mutations were performed. Genetic testing was positive for DM2 (2650 CCTG repeat) and for a variant c.215C>T (p.Pro72Leu) in the SCN4A gene. The variation affects the cytoplasmic N terminus domain of Nav1.4, where mutations have never been reported. The biophysical properties of the mutant Nav1.4 channels were evaluated by whole-cell voltage-clamp analysis of heterologously expressed mutant channel in tsA201 cells. Electrophysiological studies of the P72L variant showed a hyperpolarizing shift (-5mV) of the voltage dependence of activation that may increase cell excitability. This case suggests that SCN4A mutations may enhance the myotonic phenotype of DM2 patients and should be screened for atypical cases with severe myotonia.

Objective: To review the current evidence and make practice recommendations regarding the diagnosis and treatment of limb-girdle muscular dystrophies (LGMDs). Methods: Systematic review and practice recommendation development using the American Academy of Neurology guideline development process. Results: Most LGMDs are rare, with estimated prevalences ranging from 0.07 per 100,000 to 0.43 per 100,000. The frequency of some muscular dystrophies varies based on the ethnic background of the population studied. Some LGMD subtypes have distinguishing features, including pattern of muscle involvement, cardiac abnormalities, extramuscular involvement, and muscle biopsy findings. The few published therapeutic trials were not designed to establish clinical efficacy of any treatment. Principal recommendations: For patients with suspected muscular dystrophy, clinicians should use a clinical approach to guide genetic diagnosis based on clinical phenotype, inheritance pattern, and associated manifestations (Level B). Clinicians should refer newly diagnosed patients with an LGMD subtype and high risk of cardiac complications for cardiology evaluation even if they are asymptomatic from a cardiac standpoint (Level B). In patients with LGMD with a known high risk of respiratory failure, clinicians should obtain periodic pulmonary function testing (Level B). Clinicians should refer patients with muscular dystrophy to a clinic that has access to multiple specialties designed specifically to care for patients with neuromuscular disorders (Level B). Clinicians should not offer patients with LGMD gene therapy, myoblast transplantation, neutralizing antibody to myostatin, or growth hormone outside of a research study designed to determine efficacy and safety of the treatment (Level R). Detailed results and recommendations are available on the Neurology® Web site at Neurology.org.Neurology® 2014;83:1453–1463

A collection of more than 30 genetic muscle diseases that share certain key features, limb-girdle muscular dystrophies are characterized by progressive weakness and muscle atrophy of the hips, shoulders, and proximal extremity muscles with postnatal onset. This article discusses clinical, laboratory, and histologic features of the 6 most prevalent limb-girdle dystrophies. In this large group of disorders, certain distinctive features often can guide clinicians to a correct diagnosis.

The limb-girdle muscular dystrophies (LGMDs) encompass a collection of genetic muscle diseases with proximal-predominant weakness of the limbs. Thirty-two of these disorders are named via the common nomenclature, including 8 autosomal-dominant (LGMD1A-H) and 24 autosomal-recessive (LGMD2A-X) disorders.(1) In addition, numerous other genetic muscle diseases, including Bethlem myopathy, dystrophinopathies, ryanodine receptor-associated myopathies, and many more, may clinically present with similar proximal-predominant weakness.(2) Therefore, current genetic testing panels targeting neuromuscular weakness frequently encompass75 genes. These disorders are quite rare, each with minimum prevalence estimates of 0.01-0.60 cases per 100,000 persons.(3) LGMD2A (attributable to mutations in the gene for calpain-3) and LGMD2B (attributable to mutations in the gene for dysferlin) consistently are the 2 most prevalent LGMD subtypes in a variety of ethnic cohorts.

The cause of sporadic amyotrophic lateral sclerosis (ALS) is not known. Studies associate toxic, dietary, infectious, neoplastic, and physical factors as underlying, predisposing, or pathogenic influences. Historical, conventional, and novel disease mechanisms, acting solely or in concert, convert previously healthy individuals into terminally ill patients. Despite intensive investigations in the previous decades, the underlying cause and effective treatments elude researchers. Discovering causative mechanisms in sporadic ALS will facilitate effective treatments and cures for this disorder. After a brief review of the disease process itself, this article discusses potential environmental influences on the development of ALS.

We studied two 16-year-old males with juvenile muscular atrophy of the distal arm, "Hirayama disease," resulting in asymmetric atrophy and weakness of the distal upper extremities. Pathogenic theories include a compressive myelopathy with or without ischemia, and occasional cases are accounted for by genetic mutations. To specifically address the ischemia hypothesis we performed spinal angiography and epidural venography. Neck flexion during spinal angiography showed a forward shift of a nonoccluded anterior spinal artery without impedance to blood flow. Epidural venography demonstrated engorgement of the posterior epidural venous plexus without obstruction to venous flow. The findings do not support large vessel obstruction as a contributory factor. The Hirayama hypothesis continues to best explain the disease pathogenesis: neck flexion causes tightening of the dura and intramedullary microcirculatory compromise with resultant nerve cell damage. The age-related factor can most likely be accounted for by a growth imbalance between the vertebral column and the cord/dural elements. Resolution of progression is associated with cessation of body growth, after which the symptoms plateau or modestly improve. Muscle Nerve 40: 206-212, 2009.

Limb-girdle muscular dystrophy (LGMD) has been linked to 15 chromosomal loci, 7 autosomal-dominant (LGMD1A to E) and 10 autosomal-recessive (LGMD2A to J). To determine the distribution of subtypes among patients in the United States, 6 medical centers evaluated patients with a referral diagnosis of LGMD. Muscle biopsies provided histopathology and immunodiagnostic testing, and their protein abnormalities along with clinical parameters directed mutation screening. The diagnosis in 23 patients was a disorder other than LGMD. Of the remaining 289 unrelated patients, 266 had muscle biopsies sufficient for complete microscopic evaluation; 121 also underwent Western blotting. From this combined evaluation, the distribution of immunophenotypes is 12% calpainopathy, 18% dysferlinopathy, 15% sarcoglycanopathy, 15% dystroglycanopathy, and 1.5% caveolinopathy. Genotypes distributed among 2 dominant and 7 recessive subtypes have been determined for 83 patients. This study of a large racially and ethnically diverse population of patients with LGMD indicates that establishing a putative subtype is possible more than half the time using available diagnostic testing. An efficient approach to genotypic diagnosis is muscle biopsy immunophenotyping followed by directed mutational analysis. The most common LGMDs in the United States are calpainopathies, dysferlinopathies, sarcoglycanopathies, and dystroglycanopathies.

This treatise briefly discusses the genetic features of ALS and reviews environmental exposures in sporadic ALS. At least 10 genetic foci are responsible for cases of familial motor neuron disease and more are yet to be discovered. Research into sporadic ALS suggests that abundant factors apparently participate in the disease process. A singular cause and unifying disease and nerve dysfunction in polyneuropathies, a multitude of genetic, toxic, autoimmune, infectious, and systematic processes seem to be at play. The ALS syndrome likely will not be dissimilar.

The limb girdle muscular dystrophies (LGMDs) represent a genetically diverse group of disorders. Currently, chromosomal loci are known for at least 5 autosomal-dominant and 10 autosomal-recessive subgroups. In 13 of these, recognized genes and protein products generate an assortment of phenotypes, some unique and many overlapping. In some disorders, novel clinical features are sufficiently distinct so as to proffer clues to the diagnosis of a specific LGMD subtype. An armamentarium of laboratory tools is required to confirm specific subtypes of LGMD. These might only be available in neuromuscular centers specializing in this form of dystrophy. Currently, supportive therapy is the predominant means of treatment, but further understanding of unique pathogenic mechanisms holds promise for the future.

Molecular and genetic breakthroughs continue to explode our knowledge of the limb-girdle muscular dystrophies. Despite a common, basic phenotype, the more than 25 genes underlying these genetic muscle diseases lead to substantial heterogeneity in pathogenesis and clinical course. Distinctive clinical, laboratory, and biopsy features often help to distinguish among them. Treatment remains predominantly supportive with excitement surrounding the genetic-based therapies.

Few prospective, randomized, placebo-controlled trials have been performed to guide clinicians in the management of neuropathies seen in the setting of monoclonal gammopathies (paraproteins). Recommendations must be made on the basis of clinical experience and information gleaned from various uncontrolled and open-label trials. In every instance, decisions concerning therapy must be based on the clinical setting in which the paraprotein occurs. •Treatment of paraproteinemic neuropathies associated with multiple myeloma, amyloidosis, and Waldenstrom’s macroglobulinemia should be directed at the treatment of the underlying disease. These neuropathies often remain recalcitrant to therapy. •If the paraprotein results from cryoglobulinemia due to hepatitis C virus infection, interferon-α (with or without ribavirin) provides optimal subjective and objective relief from symptoms. •For neuropathy associated with osteosclerotic myeloma (POEMS syndrome) and solitary bone lesions, radiation therapy is the most effective and least toxic initial therapy. •In those patients with monoclonal gammopathies of undetermined significance (MGUS), consideration of the clinical syndrome may be very helpful in selecting appropriate treatment. Patients who fulfill diagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are best treated in a manner similar to that used for idiopathic CIDP (ie, with intravenous immunoglobulin, plasma exchange, and corticosteroids). •Class I evidence documents plasma exchange to be effective in peripheral neuropathies associated with MGUS of the IgG and IgA, but not IgM, types. •The most difficult cases to treat are those with peripheral neuropathies associated with IgM monoclonal gammopathies, with or without reactivity to myelin-associated glycoprotein (MAG). A number of published case series propose therapeutic regimens for these conditions, yet optimal treatment remains to be established. In many cases, mildly symptomatic patients should not be subjected to the morbidity associated with current treatment regimens. In those patients requiring treatment, this author initially tries plasma exchange, followed by a course of chlorambucil if the symptoms and signs are predominantly sensory. For cases with rapid progression or significant disability, a regimen of monthly pulses with prednisone and cyclophosphamide is recommended. If improvement does not ensue, a trial of a newer agent, such as rituximab, is recommended. •Supportive treatment with physical therapy, orthotics, and ambulatory aids enhances patient independence at a relatively low cost.

Purpose of review With transition to the genetic era, the number of muscular dystrophies has grown significantly, but so too has our understanding of their pathogenic underpinnings. Clinical features associated with each muscular dystrophy still guide us to the diagnosis. However, improved diagnostic abilities refine and expand phenotypic and genotypic correlates. This article discusses the epidemiology, clinical features, and diagnosis of these disorders. Recent findings Some important recent advancements include (1) a much greater understanding of the pathogenetic pathways underlying facioscapulohumeral muscular dystrophy and myotonic dystrophy type 1; (2) the publication of diagnostic and treatment guidelines for Duchenne muscular dystrophy; and (3) further clarification of the many genetic muscle disorders presenting a limb-girdle pattern of weakness. Summary Muscular dystrophies are genetic, progressive, degenerative disorders with the primary symptom of muscle weakness. Duchenne, Becker, facioscapulohumeral, and myotonic muscular dystrophies are most prevalent and tend to have distinctive features helpful in diagnosis. The limb-girdle, Emery-Dreifuss, and oculopharyngeal muscular dystrophies are less common but often may also be diagnosed on the basis of phenotype. Researchers hope to help patients with future discoveries effective in slowing or halting disease progression, reversing or preventing underlying mechanisms, and repairing previously damaged muscle.

We studied two 16-year-old males with juvenile muscular atrophy of the distal arm, "Hirayama disease," resulting in asymmetric atrophy and weakness of the distal upper extremities. Pathogenic theories include a compressive myelopathy with or without ischemia, and occasional cases are accounted for by genetic mutations. To specifically address the ischemia hypothesis we performed spinal angiography and epidural venography. Neck flexion during spinal angiography showed a forward shift of a nonoccluded anterior spinal artery without impedance to blood flow. Epidural venography demonstrated engorgement of the posterior epidural venous plexus without obstruction to venous flow. The findings do not support large vessel obstruction as a contributory factor. The Hirayama hypothesis continues to best explain the disease pathogenesis: neck flexion causes tightening of the dura and intramedullary microcirculatory compromise with resultant nerve cell damage. The age-related factor can most likely be accounted for by a growth imbalance between the vertebral column and the cord/dural elements. Resolution of progression is associated with cessation of body growth, after which the symptoms plateau or modestly improve. Muscle Nerve 40: 206-212, 2009.

Miyoshi myopathy, caused by mutations in the membrane protein dysferlin, is the most common muscular dystrophy that presents in the posterior calves. Its onset is before the age of 30 years and it is associated with marked elevations of serum creatine kinase (CK). In contrast, little is known about calf myopathies with onset after the age of 30, and it is not clear whether such patients have a dysferlinopathy. We describe five patients with a myopathy predominantly affecting the calf muscles, with onset after the age of 30. Muscle tissue was analyzed by immunoblot for dystrophin and dysferlin. All five had normal dysferlin but one had a dystrophinopathy. Serum CK levels ranged from 3 to 15 times the upper limit of normal. In contrast, all of 13 patients presenting before age 30 with calf weakness had a dysferlinopathy. Thus, isolated calf atrophy and weakness with onset after age 30, and associated with serum CK levels that are only moderately elevated, represents a distinct myopathy phenotype. Most of these cases are sporadic, although the overall phenotype appears genetically heterogeneous and dysferlinopathy is uncommon.

WCN 2013 No: 1825 Topic: 7 Neuromuscular disorders Severe myotonia in juvenile myotonic dystrophy type 2 and sodium channel gene mutation E. Bugiardini, A. Soriano Caminero, R. Cardani, A. Botta, M.P. Wicklund, G. Meola. Neurology, IRCCS Policlinico San Donato, University of Milan, Milan, Italy; Department of Neurology, Hershey Medical Center, Milton South, PA, USA; Lab of Muscle Histopathology and Molecular Biology, IRCCS Policlinico San Donato, Milan, Italy; Department of Biopathology and Diagnosing Imaging, Tor Vergata University of Rome, Roma, Italy Background: Myotonic dystrophy type 2 (DM2) is an adult onset muscular dystrophy caused by a dominantly transmitted (CCTG)n expansion in intron 1 of the ZFN9 gene. Myotonia generally is mild and inconsistent in DM2. A severe or a juvenile onset myotonia may hide additional genes and/or modifying factors that need to be explored. An association between severe myotonia in DM2 and the presence of recessive chloride channel (CLCN1) mutation has been reported (Cardani R et al. 2012). A similar association with sodium channel gene (SCN4A) mutation has not been described. Objective: To describe a family with atypical DM2 phenotype characterized by severe myotonia of early onset. Case description: A 25 year old girl complained of hand cramping and difficulty to relax after activity. Neurological examination showed thenar percussion myotonia and mild distal weakness. EMG showed myotonic discharges in all muscles examined and genetic testing was positive for DM2. Genetic screening for CLCN1 did not identify any alteration in DNA sequence. The analysis of SCN4A gene revealed a SCN4A variant c.215CNT (p.Pro72Leu). Both SIFT and PolyPhen-2.2.2. (HumVar) predicted that this variant is pathogenetic. It may justify the atypical phenotype characterized by severe myotonia of the patient. Conclusion: A severe and early myotonia in juvenile DM2 suggests the presence of modifying factors contributing to the phenotype. A screening of SCN4A gene is thus recommended in addition to CLCN1. doi:10.1016/j.jns.2013.07.1627 Abstract WCN 2013 No: 333 Topic: 7 Neuromuscular disorders Sonoporation delivered gold nanoparticles for myopathy treatment on rat model WCN 2013 No: 333 Topic: 7 Neuromuscular disorders Sonoporation delivered gold nanoparticles for myopathy treatment on rat model M.Y. Spivak, R.V. Bubnov, L.M. Lazarenko, N.O. Tymoshok. Immunology, Zabolotny Institute of Microbiology and Virology of the National Academy of Sciences of Ukraine, Kyiv, Ukraine; Ultrasound, Clinical Hospital ‘Pheophania’ of State Affairs Department, Kyiv, Ukraine Background: Gold nanoparticles shown strong cardiomyoprotective effects,metallic nanoparticles enhance viability of a variety of neural cells. Objectives: The aim was to test the myoprotective effects of gold nanoparticles on myopathy rat model, and to test the sonoporation effect to increase nanoparticles' delivery into myocytes. Material and methods: Wistar 180–200 g rats (of each sex were selected on the basis of analogies (n = 30) were included for the experiment to model statin-induced advance myopathy, registered by ultrasonography using transducers up to 12 MHz. We formed three groups of animals: the 1st group received colloid 20 nm nanogold (193 mg/ml for metal) injected into the injured muscle using 31 G needles under US guidance; the 2nd group of rats received additional insonation of injection locus in depth of 1 cm by 180 s by 130 Db 3–8 MHz ultrasound; and the 3rd group was the control. Morphological, laboratory, and ultrasound assessments were performed. Results: In animals after nanogold injection regression of myopahywas registered clinically, on US. Light-optical microsopy defined in tissue samples the regression of muscle damage, vakuoli degeneration and myofibril lysis. Nanogold induced significant inhibition of Ca, Mg-ATPase activity in myofibrils after (1st vs 3rd group, p b 0.01). Electron microscopy demonastrated higher nanoparticle cumulation in myofibrils and mitochondria (P b 0.01 for both). Myopathy regression was clearly defined in all rats after sonoporation (1st vs 2nd group p b 0.05). Conclusions:Gold nanoparticles have significantmyoprotective effects, being a potential strategy for the treatment of muscular dystrophies, applicable for disperse localizations. Sonoporation is able to enhance gold nanoparticle delivery to myocytes in vivo. doi:10.1016/j.jns.2013.07.1628 Abstract WCN 2013 No: 2168 Topic: 7 Neuromuscular disorders A novel mitofusin 2 MFN2 gene mutation causing early onset Charcot-Marie-Tooth 2A disease: Genetic, clinical and MR spectroscopy characterization WCN 2013 No: 2168 Topic: 7 Neuromuscular disorders A novel mitofusin 2 MFN2 gene mutation causing early onset Charcot-Marie-Tooth 2A disease: Genetic, clinical and MR spectroscopy characterization M. Vavla, A. Martinuzzi, M. Domenico, F. Frijia, G. Aghakhanyan, M.L. Mostacciuolo, E. Carraro, V. Casanova. Conegliano Research Centre, IRCCS ‘E. Medea’ Conegliano, Italy; U.O. Neuroradiologia, Fondazione CNR/Regione Toscana G. Monasterio, Italy; Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy; Department of Biology, University of Padova, Conegliano, Italy; ‘E. Medea’ Scientific Institute, Conegliano Research Centre, Conegliano, Italy Background: Mitofusin 2 (MFN2) mutations are associated with axonal peripheral neuropathies known as Charcot-Marie-Tooth 2A (CMT2A). Even though central nervous system (CNS) involvement has been described in CMT2A, there are as to now no advanced neuroimaging study of patients with MFN2 mutations. We describe a novel MFN2 mutation detailing its clinical presentation, and describing novel neuroimaging findings. Materials and methods: A 7 yo boy with unremarkable family history underwent neurological assessment and gait analysis. Routine electrophysiological investigation (EMG and ENG) was consistent with axonal polyneuropathy. TheMFN2 gene sequencewas analyzed. Neuroimaging included standard morphological and spectroscopic (MRS) sampling. Results: Sequence analysis showed a novel MFN2 mutation (c.2116A → C, T706P). Sequence analysis on the parents confirmed it as a de-novo mutation. The residue is situated between the transmembrane domain and the coiled-coil region close to the C-terminal. The clinical features included early onset with steppage, hyporeflexia and hypopallestesia. Computerized gait analysis demonstrated primary distal lower limb involvement with club feet and accentuation of the hips and knee flexion. Standard MRI didn't reveal brain signal alterations. MRS showed an increase of NAA and Cho peaks. Discussion: This novel mutation (T706P) is associated with early onset CMT2A. The MRI findings, in the absence of macroscopical brain signal alterations, show MRS data suggestive of whole brain biochemical involvement (elevated NAA, increased Cho). These findings, especially in such a young patient, confirmCMT2A as a disease involving both CNS Abstracts / Journal of the Neurological Sciences 333 (2013) e422–e480 e456