Journal of Clinical Neuromuscular Disease最新文献

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.

Abstract: This update starts with an interesting series of children and adults with congenital myasthenic syndrome with a DOK7 variant. The next section is on autoimmune myasthenia gravis (MG) epidemiology, cost of care, and hospitalizations. A number of studies on the newer treatments are discussed including a phase 2 trial of nipocalimab and recommendations for using some of these drugs. A large trial emphasizing the negative effects of pyridostigmine in muscle-specific kinase MG is covered. A study on the incidence of taste disorders and alopecia in MG follows. The update ends with the topic of the burden of disease in MG and Lambert-Eaton myasthenic syndrome.

Introduction: Small-fiber neuropathy (SFN) is highly prevalent but often idiopathic. TS-HDS, FGFR-3, and Plexin D1 autoantibodies (seropositive) may be present in more than 40% of idiopathic cases. Another autoimmune biomarker is a non-length-dependent (NLD) skin biopsy pattern. Our goal was to demonstrate that small-vessel vasculitis and perifolliculitis (inflammation) on skin biopsies are additional biomarkers.

Methods: All pure SFN skin biopsy reports were reviewed for inflammation, and their charts were examined for other relevant history.

Results: Seven of 80 patients with pure SFN had inflammation (8.8%); 5 patients were female (71%) and 2 were male (29%); average age was 45 (16-67). All 7 patients with inflammation were seropositive (100%, P = 0.0495), and 6 patients (86%) had either NLD inflammation or NLD pathology (P = 0.0003).

Discussion: Inflammation is present only in a small portion of punch biopsies, but may be another autoimmune SFN biomarker. It is strongly associated with seropositivity and NLD-pathology. Further studies are likely indicated to assess inflammation pathophysiology and immunotherapy responsiveness.