Journal of Clinical Neuromuscular Disease最新文献

Introduction: Peripheral nerve injuries are being increasingly recognized in patients recovering from severe SARS-CoV-2 infections. Axonal neuropathies can occur, leading to lasting and disabling deficits.

Case reports: We present the cases of 3 patients who developed weakness and sensory symptoms after severe SARS-CoV-2 pneumonia. The clinical deficits revealed various patterns of injury including a mononeuropathy multiplex (MNM) in the first patient, a brachial plexopathy with superimposed MNM in the second patient, and a mononeuropathy superimposed on a polyneuropathy in the third patient. Electrodiagnostic studies revealed axonopathies. The patients with MNM were left with severe disability. The third patient returned to his baseline level of functioning.

Conclusions: Severe SARS-CoV-2 infections can result in disabling axonopathies. Possible explanations include ischemic nerve damage from the profound inflammatory response and traumatic nerve injuries in the ICU setting. Preventing severe disease through vaccination and antivirals may therefore help reduce neurologic morbidity.

Abstract: Myasthenia gravis (MG) is an autoimmune disease of multifactorial etiology in which genetic factors and cytokines seem to play an important role. The aim of this study was to investigate potential associations of cytokines single nucleotide polymorphisms (SNPs) and MG in Algerian patients. We performed a case-control study that included 27 patients and 74 healthy subjects. Cytokines SNPs genotyping was performed by the polymerase chain reaction sequence-specific primers (PCR-SSP) method. Our results showed that the TNF-α -308G/A (P < 0.005) and TGF-β1 +869T/T (P < 0.05) genotypes were more frequent among patients with MG compared with healthy individuals, whereas TNF-α -308G/G (P < 0.0001), TGF-β1 +869T/C (P < 0.05), and IFN-γ +874A/A (P < 0.05) were less frequent. Our results also showed that IL-10 and IL-6 SNPs did not show any significant difference in distribution between MG patients and healthy individuals. Our observations support the hypothesis that implicates genetic variants of certain cytokines in MG. However, ours results should be replicated with a larger sample size. In addition, the precise underlying processes remain to be clarified.

Highlights: TNF-α -308G/A and TGF-β1 +869T/C genotypes predispose to MG.IFN-γ +874A/A genotype protects against MG.IL-6 -174C/G SNP is not associated with MG.

Abstract: Congenital myasthenic syndromes (CMS) are relatively rare neurologic syndromes of defective neuromuscular transmission that stem from mutations in various proteins at the myoneural junction. Classically, the patients present within the first 2 years of life; however, the disease can also have onset in the second or third decade of life. The disease characteristically involves the skeletal muscles and spares smooth and cardiac muscles. The patients present with weakness involving ocular, limb, axial, or bulbar muscles. The specific diagnosis in most cases is clinched by genetic testing. We report a 59-year-old man presenting with neuromuscular weakness for 3 years and calf hypertrophy. He had myopathic features on electrophysiologic studies with a decremental response on repetitive nerve stimulation. Genetic testing confirmed a diagnosis of DOK7 CMS. He was managed with salbutamol and showed significant improvement.

Abstract: The diagnosis of Duchenne and Becker muscular dystrophy (DBMD) is made by genetic testing in approximately 95% of cases. Although specific mutations can be associated with skeletal muscle phenotype, pulmonary and cardiac comorbidities (leading causes of death in Duchenne) have not been associated with Duchenne muscular dystrophy mutation type or location and vary within families. Therefore, identifying predictors for phenotype severity beyond frameshift prediction is important clinically. We performed a systematic review assessing research related to genotype-phenotype correlations in DBMD. While there are severity differences across the spectrum and within mild and severe forms of DBMD, few protective or exacerbating mutations within the dystrophin gene were reported. Except for intellectual disability, clinical test results reporting genotypic information are insufficient for clinical prediction of severity and comorbidities and the predictive validity is too low to be useful when advising families. Including expanded information coupled with proposed severity predictions in clinical genetic reports for DBMD is critical for improving anticipatory guidance.

Objectives: To determine the relationship between the number of plasma exchanges and clinical outcome in patients experiencing myasthenic crisis.

Methods: We retrospectively reviewed all episodes of myasthenia gravis exacerbation/crisis who received plasmapheresis in patients admitted to a single-center tertiary care referral center from July 2008 to July 2017. We performed statistical analyses to determine whether the increased number of plasma exchanges improves the primary outcome (hospital length of stay) and the secondary outcome (disposition to home, skilled nursing facility, long-term acute care hospital, or death).

Results: There is neither clinically observable nor statistically significant improvement in length of stay or disposition on discharge in patients who received 6 or greater sessions of plasmapheresis.

Conclusions: This study provides class IV evidence that extending the number of plasma exchanges beyond 5 does not correlate with decreased hospital length of stay or improved discharge disposition in patients experiencing myasthenic crisis.

Objectives: To evaluate patient attitudes and beliefs toward thymectomy for myasthenia gravis (MG).

Methods: The Myasthenia Gravis Foundation of America administered a questionnaire to the MG Patient Registry, an ongoing longitudinal survey of adult MG patients. Questions assessed reasons for or against thymectomy and how hypothetical scenarios would have affected their decision.

Results: Of 621 respondents, 190 (31%) reported a history of thymectomy. Of those who underwent thymectomy for nonthymomatous MG, 97 (51.6%) ranked symptom improvement as most important and 100 (53.2%) ranked reducing medication as least important. Among 431 nonthymectomy patients, the most frequent reason for not undergoing thymectomy was that their doctor did not discuss it (152 of 431 = 35.2%) and 235 (56.8%) said that they would have considered it more strongly if their doctor spent more time discussing it.

Conclusions: Thymectomies are motivated more by symptoms than by medication, and a lack of neurologist discussion is the most common barrier to thymectomy.

Abstract: The Neonatal Fc Receptor (FcRn) is integral to a wide variety of processes including IgG recycling, serum albumin turnover, and bacterial opsonization. Thus, targeting FcRn will increase antibody degradation including pathogenic IgGs. FcRn inhibition provides a novel therapeutic mechanism by which autoantibody titers are reduced resulting in clinical improvement and disease abatement. The FcRn targeting mechanism is similar to that of intravenous immunoglobulin (IVIg) in which saturated FcRn facilitates accelerated pathogenic IgG degradation. Recently, the FcRn inhibitor efgartigimod was approved for the treatment of myasthenia gravis. Subsequently, clinical trials of this agent have been conducted for numerous inflammatory conditions involving pathogenic autoantibodies. These disorders include the Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, and inflammatory myositis. Other disorders traditionally treated with IVIg may also benefit from FcRn inhibition in certain contexts. This manuscript discusses the mechanism of FcRn inhibition, preclinical data, and the results of clinical trials of this agent for a wide range of neuromuscular diseases.