Journal of Clinical Neuromuscular Disease最新文献

Abstract: Mitochondrial fatty acid β-oxidation disorders are autosomal recessive disorders that impair mitochondrial β-oxidation and transport of fatty acids. These disorders have diverse clinical presentations. The neonatal-onset form presents with hyperammonemia, transient hypoglycemia, metabolic acidosis, cardiomyopathy, and sudden death. The Late-onset form presents with neuropathy, myopathy, and retinopathy. We report a case of a 25-year-old man who presented with episodic weakness, exercise intolerance, myalgia, and rhabdomyolysis. Whole-exome sequencing identified a pathogenic variant in acyl-Coenzyme A dehydrogenase very long chain gene, confirming a diagnosis of very long-chain acyl-Coenzyme A dehydrogenase deficiency (autosomal recessive).

Abstract: This update begins with the incidence and features of statin-associated muscle symptoms, which may often be misattributed. Articles on potential muscle mitochondria dysfunction from statins follow, along with recommendations for possibly avoiding statins in some patients with genetic myopathies. Next, autoimmune myopathies, including immune-mediated necrotizing myopathy, myositis with antimitochondrial antibodies, and overlap myositis with lupus, as well as the role of myxovirus protein A identification in muscle specimens, are addressed. The next section includes reports on the significance of elevated serum aldolase with normal creatine kinase and recommended approaches to evaluate a patient with rhabdomyolysis. A cluster of reports on muscle imaging, particularly using ultrasound and magnetic resonance imaging, are covered. They include studies of inherited and inflammatory myopathies and neck extensor myopathy on topics such as imaging features, patterns of involvement, diagnostic utility, and correlation with histopathology. Last, there are discussions on mexiletine versus lamotrigine for nondystrophic myotonias and the treatment of fatty acid oxidation disorders in adults.

Objectives: The aim of this prospective, longitudinal study was to validate video-oculography (VOG) for early detection of myasthenia gravis (MG) in patients with clinical suspicion of MG but lacking confirmatory laboratory results.

Methods: Thirteen individuals suspected of having MG were studied using a 3-dimensional VOG system. Oculomotor fatigability, defined as the decrement (%) between the second and the last 5 average measures, was calculated.

Results: Significant reductions in oculomotor ranges were found, exceeding previous cutoff values for horizontal saccades (16.4 ± 9.8%), vertical saccades (18.7 ± 12.6%), horizontal smooth pursuit (15.7 ± 6.0%), and vertical smooth pursuit (27.2 ± 17.4%). Despite initially negative laboratory tests, many participants later tested positive on the neostigmine test (92.3%) and repetitive nerve stimulation tests (69.2%).

Conclusions: VOG is a reliable diagnostic tool for MG, particularly useful for seronegative patients, allowing for earlier and more accurate diagnosis than conventional methods.

Abstract: Pathogenic variants in FHL1 are associated with X-linked reducing body myopathy, scapuloperoneal myopathy, myopathy with postural muscle atrophy or Emery-Dreifuss muscular dystrophy type 6. Emery-Dreifuss muscular dystrophy is characterized by joint contractures in childhood, progressive muscle weakness that starts in a humeroperoneal distribution and later extends to scapular and pelvic girdle muscles, and cardiac involvement that include conduction defects or cardiomyopathy. In this study, we report diagnosis of a patient with Emery-Dreifuss muscular dystrophy type 6 after identification of a novel deletion in FHL1, whose pathogenicity was clarified by RNA sequencing.

Abstract: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting primarily the motor system. However, an association with sensory neuronopathy has been scarcely described. We described 3 unrelated patients (2 males) with sporadic spinal-onset ALS and sensory neuronopathy. Mean onset age was 63.7 years and mean Revised Amyotrophic Lateral Sclerosis Functional Rating Scale at diagnosis was 42. Sensory disturbances emerged before or overlap with motor symptoms in the same onset region and followed the same pattern of lower motor neuron involvement over disease progression. Two patients have also bilateral trigeminal sensory fibers affection. None had cognitive abnormalities. Genetic testing for the most common ALS-associated genes was unrevealing. Mean disease duration and ALS functional rating scale-revised at last visit was 47 months and 27, respectively. One patient is still alive, dependent on nocturnal noninvasive ventilation. Motor neuron disease is now considered a multisystem neurodegenerative disorder, and sensory neuronopathy, although very rare, should not be neglected as a possible part of the disease spectrum.

Abstract: Three therapies are now available for the treatment of type 1 spinal muscular atrophy: onasemnogene abeparvovec (OA), nusinersen, and risdiplam. We present a retrospective, single-center case series detailing our center's experience with six patients diagnosed with type 1 spinal muscular atrophy who switched from risdiplam to OA. Risdiplam was discontinued the day before the OA infusion, and we evaluate the safety aspects of this switch. All patients continued risdiplam until the day before administration of OA, with a wash out period of between 24 and 33 hours prior. All patients have had follow-up for at least 12 weeks, while 3 patients who lived locally received ongoing follow-up ranging from 14 to 27 months after OA infusion. All patients remained stable or improved in their motor scores and need for ventilatory support and feeding support requirement. Adverse events reported after OA switch included tachycardia, fever, nausea, vomiting, raised transaminases, and mild neutropenia. All adverse events in these children were either known adverse events of OA or were not considered secondary to OA or risdiplam treatment. No unexpected adverse event was demonstrated post-OA in patients stopping risdiplam a day before OA infusion. Data presented here suggest that stopping risdiplam a day before OA treatment did not seem to be associated with increased risk.

Background: Pathogenic variants in the nonmuscle myosin, MYH14, have been associated with several pathologic conditions including a complex phenotype with peripheral neuropathy, myopathy, hoarseness, and hearing loss. Since its first description in a large Korean kindred, this rare neuromuscular disorder has further been characterized in 1 American and 1 Canadian pedigree.

Case presentation: Here, we describe a German patient with atypical MYH14-related neuromuscular disorder. The clinical phenotype included signs of a distal myopathy with early respiratory involvement and a prominent hoarseness and peripheral neuropathy. In contrast to previous reports, no relevant deafness was identified. Muscle biopsy indicated a vacuolated myopathy with excessive autophagy, whereas histology of the sural nerve showed signs of a mixed axonal-demyelinating neuropathy. Next-generation sequencing revealed a loss-of-function variant not identified so far in the MYH14 gene (c.4510del, p.[Arg1504Glyfs*10]). Because of rapid disease progression with respiratory failure, the patient died at the age of 52.

Conclusions: We present a novel MYH14 variant resulting in a severe and rapidly progressive MYH14-associated phenotype with predominantly distal myopathy, early respiratory failure, dysphagia, hoarseness, and peripheral neuropathy, without hearing loss. This case expands the clinical spectrum of MYH14-related neuromuscular disorders by providing a new clinical phenotype and disease course and histopathologic features.

Objectives: We aim to characterize the clinical, pathological, laboratory and imaging features of various antibody defined IIM subgroups in Indian population.

Methodology: 103 patients who satisfied 2017 ACR/ EULAR Classification criteria for IIM, and tested seropositive for myositis antibodies using Immunoblot technique were retrospectively identified. Patients were classified into following subgroups - Mi2B group, SRP group, Anti RNA Synthetase antibody group (Jo 1, PL 7, PL 12, OJ), multiple MSA, only MAA group (U1RNP, Ro 52, SS-A, SS-B, PM Scl 75, PM Scl 100). Clinical, laboratory, histopathology and imaging parameters were compared among different groups.

Results: Ro52 (n = 31; 22.46%) was the most common autoantibody seen in our cohort followed by Mi2B (n = 26; 18.84%) and SRP (n = 20; 14.49%). Skin manifestations (p = 0.053) and joint involvement (p = 0.023) were seen more frequently among Mi2B and MAA sub groups. Three out of 4 patients with persisting antibody positivity on serial measurements developed clinical relapse between 2 and 3 years after the initial episode. Remaining 2 patients showed declining titres of antibodies and developed no clinical relapses during follow up period of 5 and 6 years. Among histopathology features, perifascicular atrophy was found to be more prevalent among Mi2B (55.6%) and MAA subgroups (31.3%) (p value = 0.037). In thigh muscle MRI, Mi2B group showed a pattern of diffuse involvement of affected muscles without regional preference, with sparing of hamstring group. SRP group showed characteristic pattern of edema involving peripheral regions of Quadriceps femoris and central regions of Adductor group along with severe atrophy involving hamstring and adductor compartment muscles. ILD was seen in 27.5% of patients who underwent CT Chest. 3 patients were found to have underlying malignancy at the time of diagnosis of myositis (Mi2B = 2 and PM Scl = 1).

Conclusion: Classification of IIM patients based on myositis antibodies yields subgroups with certain differences in clinical, laboratory, histopathological and imaging features.

Abstract: Spinal muscular atrophy is an incurable inherited disease caused by lower motor neuron death from mutations of the survival motor neuron genes. Intrathecal therapy with the antisense oligonucleotide, nusinersen, has been demonstrated to be beneficial in children with this disease, but the experience in adults, particularly ambulatory patients, is limited. We present a prospective observational case series from a single center using nusinersen therapy where we categorize 6 adult patients with spinal muscular atrophy into 2 functional categories: ambulatory (n = 3) or nonambulatory (n = 3). All received therapy that was administered intrathecally every 4 months. We monitored the course and laboratory data for 1 year and observed for side effects. There was no significant deterioration for 1 year. There was some minor improvement particularly in subjective changes. The benefit seems to decrease after 3 months. No significant complications were observed.