Current Opinion in Neurology最新文献

Purpose of review: Late-onset myopathies are defined as muscle diseases that begin after the age of 50 years. Some myopathies present classically in the elderly, whereas others may have a variable age of onset, including late-onset presentation. The purpose of this review is to summarize and comment on the most recent evidence regarding the main diagnosis of late-onset myopathies focusing on genetic causes.

Recent findings: Although late-onset myopathies (LOM) are expected to be predominantly acquired myopathies, some common genetic myopathies, such as facioscapulohumeral muscular dystrophy (FSHD), can present late in life, usually with an atypical presentation. In addition, metabolic myopathies, which are classically early-onset diseases, are also diagnoses to be considered, particularly as they may be treatable. Late-onset multiple acyl-CoA dehydrogenase deficiency (MADD) has recently been identified as a cause of subacute LOM with a dramatic response to riboflavin supplementation.

Summary: Inclusion body myositis is the most frequent of all LOM. Myotonic dystrophy type 2, FSHD and oculopharyngeal muscular dystrophy are the most frequent causes of genetic LOM. We summarize the major differential diagnoses and the clinical features on clinical examination that are suggestive of a genetic diagnosis to provide a diagnostic approach.

Purpose of review: RYR1-related myopathy (RYR1-RM) is a group of myopathies caused by mutations in the RYR1 gene, which encodes the ryanodine receptor 1 (RYR1). This review discusses recent advances in the clinical features, pathology, pathogenesis, and therapeutics of RYR1-RM.

Recent findings: Although treatments such as salbutamol, pyridostigmine, and N-acetylcysteine have been explored as potential therapies for RYR1-RM, none have been conclusively proven to be effective. However, recent clinical trials of Rycal ARM210 in patients with RYR1-RM have shown promising results, including reduced fatigue and improved proximal muscle strength.Recent advances in three-dimensional structural analysis of RYR1 channels, facilitated by cryo-electron microscopy (cryo-EM), have elucidated the distinct molecular mechanisms underlying RYR1 functionality. Additionally, high-throughput screening methods, including FRET-based and endoplasmic reticulum Ca 2+ -based assays, have been successful in identifying potential candidates for the treatment of RYR1-RM.

Summary: Recent advances in clinical and pathological understanding have provided new insights into RYR1-RM. Novel pathomechanisms elucidated by cryo-EM and rapid screening methods have led to the identification of several promising drug candidates. We are hopeful about the potential of Rycal, other new drugs, and gene therapy, offering a promising outlook for the future.

Purpose of review: Recent development in understanding the pathophysiology of amyotrophic lateral sclerosis (ALS) has led to increasing number of promising test drugs in the pipeline along with the existing ones. We will review these agents focusing on ultra-high dose methylcobalamin, which is pending approval in Japan. Clinical trial design best suited for ALS will also be discussed.

Recent findings: The most recent phase 3 trial (JETALS) of ultra-high dose methylcobalamin demonstrated significant slowing of ALSFRSR changes (0.5/month), with marked reduction of serum homocysteine levels in the initial double-blind period. The post hoc analysis of the previous phase 2/3 study (E761 trial; Eisai) showed that it prolonged survival of ALS patients, if started within 1 year of onset, but the previous studies suggested its efficacy even in later stages, depending upon the rate of progression. Phase 3 trial of AMX0035 or Relyvrio on the other hand showed negative results despite the promising phase 2 data. The latter did not adjust the disease progression rate before entry.

Summary: Ultra-high dose methylcobalamin is not a vitamin supplement but a novel disease-modifying therapy for ALS, and it emphasizes homocysteine as a key factor in the disease process. Clinical trial design must include entering patients early and with similar rates of progression using pretrial observation periods for meaningful results, since ALS is a chronologically heterogenous condition with similar phenotypes.

Purpose of review: The present review will discuss the evolution of diagnostic criteria for amyotrophic lateral sclerosis (ALS) and biomarker considerations.

Recent findings: To address the limitations of existing ALS diagnostic criteria, a consortium of key stakeholders developed the Gold Coast consensus criteria (GCC). The GCC has similar or greater sensitivity compared with the revised El Escorial (rEEC) and Awaji criteria (AC), particularly for atypical phenotypes, maintained across disease duration, severity, and site of onset. In addition to improving diagnostic sensitivity, using the GCC in clinical trials may promote an increased enrolment of up to 50% of ALS patients who do not currently meet the full diagnostic eligibility requirements of the rEEC. Future inclusion of genetic biomarkers may mitigate some limitations of the GCC, to further improve diagnostic utility. In advance of such a process, validation of these biomarkers will be required before inclusion as additional criteria.

Summary: The GCC are simpler to use than previous consensus criteria, with demonstrated greater sensitivity and, enabling an earlier and more definitive ALS diagnosis, thereby facilitating wider enrolment into clinical trials. Broader implementation of the GCC in clinical trial settings is currently underway, globally.

Purpose of review: Vasculitis as a pathomechanism for neuropathy can be isolated to the peripheral nervous system, a part of a systemic autoimmune condition or a component of another syndrome. This review aims to discuss the broad range of diagnoses in which vasculitic neuropathy can be encountered, highlight the progress in imaging techniques in identifying vasculitis, and the new drugs developed for other autoimmune diseases that may be applied to neurological conditions.

Recent findings: Advances in imaging modalities, ultrasound, MRI and FDG-PET scanning for neuromuscular applications has redefined many aspects of vasculitic neuropathies. The benefit of dividing vasculitides by vessel size is becoming less absolute as diagnostic approaches advance. MRI and FDG-PET are widely used in diagnosis, defining extent of involvement of disease and monitoring. In neuralgic amyotrophy, the identification of hourglass-like constrictions on imaging has changed the treatment paradigm to include surgical interventions. These diagnostic approaches are supported by new immunomodulating and immunosuppression techniques.

Summary: Vasculitic neuropathies are a broad group of conditions with a range of causes and associations. Increased use of imaging techniques impacts our traditional definitions and classifications. The growth in treatment options for other autoimmune conditions are likely to infiltrate the neurological landscape.

Purpose of review: Leprosy is still an important cause of neuropathy. Late diagnosis is associated with development of severe nerve impairment.

Recent findings: early diagnosis and early treatment is essential in order to avoid disability and disease transmission. Recognizing that leprosy is a neurological disease is a fundamental step to the Leprosy zero action proposed by the World Health Organization.

Summary: leprosy neuropathy manifests as a mononeuropathy or a multiple mononeuropathy with a temperature-dependent distribution. Electromyography, high-resolution sonography serology and PCR help make the diagnosis. Multidrug therapy should be instituted.