A Novel Multisystem Proteinopathy Caused by a Missense ANXA11 Variant.

OBJECTIVE: Protein misfolding plays a central role not only in amyotrophic lateral sclerosis (ALS), but also in other conditions, such as frontotemporal dementia (FTD), inclusion body myopathy (hIBM) or Paget's disease of bone. The concept of multisystem proteinopathies (MSP) was created to account for those rare families that segregate at least 2 out of these 4 conditions in the same pedigree. The calcium-dependent phospholipid-binding protein annexin A11 was recently associated to ALS in European pedigrees. Herein, we describe in detail 3 Brazilian families presenting hIBM (isolated or in combination with ALS/FTD) caused by the novel p.D40Y change in the gene encoding annexin A11 (ANXA11). METHODS: We collected clinical, genetic, pathological and skeletal muscle imaging from 11 affected subjects. Neuroimaging was also obtained from 8 patients and 8 matched controls. RESULTS: Clinico-radiological phenotype of this novel hIBM reveals a slowly progressive predominant limb-girdle syndrome, but with frequent axial (ptosis/dropped head) and distal (medial gastrocnemius) involvement as well. Muscle pathology identified numerous rimmed vacuoles with positive annexin A11, TDP-43 and p62 inclusions, but no inflammation. Central nervous system was also involved: two patients had FTD, but diffusion tensor imaging uncovered multiple areas of cerebral white matter damage in the whole group (including the corticospinal tracts and frontal subcortical regions). INTERPRETATION: These findings expand the phenotypic spectrum related to ANXA11. This gene should be considered the cause of a novel multisystem proteinopathy (MSP type 6), rather than just ALS. ANN NEUROL 2021;90:239-252.

Facial myokymia in inherited peripheral nerve hyperexcitability syndrome.

Peripheral nerve hyperexcitability syndrome comprises a heterogeneous group of diseases, clinically characterised by myokymia, fasciculation, muscle cramps and stiffness. The causes are either immune mediated or non-immune mediated. Non-immune-mediated forms are mostly genetic, relating to two main genes: KCNQ2 and KCNA1 Patients with KCNQ2 gene mutations typically present with epileptic encephalopathy, benign familial neonatal seizures and myokymia, though occasionally with purely peripheral nerve hyperexcitability. We report a woman with marked facial myokymia and distal upper limb contractures whose mother also had subtle facial myokymia; both had the c.G620A (p.R207Q) variant in the KCNQ2 gene. Patients with familial myokymia and peripheral nerve hyperexcitability syndrome should be investigated for KCNQ2 variants. This autosomal dominant condition may respond to antiepileptic medications acting at potassium channels.

A novel ATP1A2 mutation in a patient with hypokalaemic periodic paralysis and CNS symptoms.

Hypokalaemic periodic paralysis is a rare genetic neuromuscular disease characterized by episodes of skeletal muscle paralysis associated with low serum potassium. Muscle fibre inexcitability during attacks of paralysis is due to an aberrant depolarizing leak current through mutant voltage sensing domains of either the sarcolemmal voltage-gated calcium or sodium channel. We report a child with hypokalaemic periodic paralysis and CNS involvement, including seizures, but without mutations in the known periodic paralysis genes. We identified a novel heterozygous de novo missense mutation in the ATP1A2 gene encoding the α2 subunit of the Na+/K+-ATPase that is abundantly expressed in skeletal muscle and in brain astrocytes. Pump activity is crucial for Na+ and K+ homeostasis following sustained muscle or neuronal activity and its dysfunction is linked to the CNS disorders hemiplegic migraine and alternating hemiplegia of childhood, but muscle dysfunction has not been reported. Electrophysiological measurements of mutant pump activity in Xenopus oocytes revealed lower turnover rates in physiological extracellular K+ and an anomalous inward leak current in hypokalaemic conditions, predicted to lead to muscle depolarization. Our data provide important evidence supporting a leak current as the major pathomechanism underlying hypokalaemic periodic paralysis and indicate ATP1A2 as a new hypokalaemic periodic paralysis gene.

Whole-body muscle magnetic resonance imaging in inflammatory myopathy with mitochondrial pathology.

Introduction: Inflammatory myopathy with mitochondrial pathology (IM-Mito) is a rare condition described in a few case series, and it is not clear whether it is a specific disease or a variant of Inclusion Body Myositis (IBM). Radiological data of IM-Mito patients has only been evaluated in one study. Aim: To analyze whole-body muscle magnetic resonance imaging (MRI) features in patients with IM-Mito compared with individuals with IBM. Methods: Fourteen IM-Mito and ten IBM patients were included. IM-Mito was defined by endomysial inflammatory infiltrate, presence of at least 1% of Cytochrome C Oxidase negative fibers, and absence of rimmed vacuoles in muscle biopsy; and IBM was defined by the presence of dystrophic muscular abnormalities, endomysial inflammatory infiltrate, and rimmed vacuoles. Patients underwent clinical evaluation and whole-body muscle MRI to determine the presence of edema, and fatty infiltration in various muscles. Results: Muscle imaging abnormalities were asymmetric in most patients with IM-Mito and IBM. Muscles with the highest average degree of fatty infiltration in both conditions were the quadriceps and medial gastrocnemius. Most patients with IM-Mito and IBM showed imaging patterns of rectus femoris relatively spared compared to other quadriceps muscles. The flexor digitorum profundus was the most affected muscle of the upper limbs in both IBM and IM-Mito. Discussion: Although the results suggest some similarities in muscle imaging features between IM-Mito and IBM, there remains uncertainty whether these two conditions are part of the same clinical spectrum.

Muscle Ultrasound Changes Correlate With Functional Impairment in Spinal Muscular Atrophy.

OBJECTIVE: We investigated ultrasound patterns of muscle involvement in different types of spinal muscular atrophy (SMA) and their correlation with functional status to determine the pattern of muscle compromise in patients with SMA and the potential role of ultrasound to evaluate disease progression. METHODS: We examined muscles (biceps brachii, rectus femoris, diaphragm, intercostals and thoracic multifidus) of 41 patients with SMA (types 1 to 4) and 46 healthy age- and sex-matched control individuals using B-mode ultrasound for gray-scale analysis (GSA), area (biceps brachii and rectus femoris) and diaphragm thickening ratio. Functional scales were applied to patients only. We analyzed ultrasound abnormalities in specific clinical subtypes and correlated findings with functional status. RESULTS: Compared with controls, patients had reduced muscle area and increased mean GSA for all muscles (p < 0.001), with an established correlation between the increase in GSA and the severity of SMA for biceps brachii, rectus femoris and intercostals (p = 0.03, 0.01 and 0.004 respectively) when using the Hammersmith Functional Motor Scale Expanded. Diaphragm thickening ratio was normal in the majority of patients, and intercostal muscles had higher GSA than diaphragm in relation to the controls. CONCLUSION: Ultrasound is useful for quantifying muscular changes in SMA and correlates with functional status. Diaphragm thickening ratio can be normal even with severe compromise of respiratory muscles in quantitative analysis, and intercostal muscles were more affected than diaphragm.

Clinical Manifestation of Nebulin-Associated Nemaline Myopathy.

Background and Objectives: Nemaline myopathy (NM) is a genetically heterogeneous inherited myopathy related with at least 12 genes, whereas pathogenic variants in NEB gene are the most common genetic cause. The clinical spectrum of NM caused by NEB pathogenic variants (NM-NEB) is very broad, ranging from mild to severe presentations manifesting with generalized weakness, as well as respiratory and bulbar involvement. There is currently not enough data regarding the progression of the disease. In this study, we present a genotypic and phenotypic spectrum of 33 patients with NM caused by NEB variants (NM-NEB) classified according to age groups and the use of ventilatory support. We focused on interventional support, genotype-phenotype correlation, and association between respiratory, bulbar, and motor systems in groups of patients stratified by age and by the use of ventilatory support (VS). Methods: Clinical and genetic data from patients with NM-NEB followed up in one specialized center were collected through regular consultations. Patients were evaluated regarding motor, bulbar, and respiratory functions. Results: Thirty-three patients with NM-NEB were evaluated consisting of 15 females and 18 males with an average age of 18 (±12) years and a median of 17 (±11) years. 32% of patients with NM-NEB used a G tube, 35% were not able to walk without support, and 55% needed VS. Scoliosis and dysphagia were more common among patients who used VS. Described for the first time, half of the patients presented tongue atrophy in a triple furrow pattern, and the presence of the atrophy was associated with dysphagia. Comparing the patients grouped by age, we found that, proportionally, older patients had more scoliosis and respiratory dysfunction than younger groups, suggesting the progression of the disease in these domains. In addition to that, we showed that VS use was associated with scoliosis and dysphagia. Discussion: NM-NEB is a very debilitating disease. There is an association between scoliosis and respiratory dysfunction while patients using VS have more often scoliosis than the no-VS group. Triple furrow tongue atrophy is a novel and frequent finding, which is directly associated with dysphagia. Grouping patients by age suggested disease stability in motor and swallow function, but a progression in respiratory dysfunction and skeletal deformities. All observations are relevant in the management care of patients with NM.

Inflammatory myopathies: an update for neurologists.

Idiopathic inflammatory myopathies (IIM) are a heterogenous group of treatable myopathies. Patients present mainly to the rheumatologist and neurologists, complaining of acute or subacute onset of proximal weakness. Extramuscular manifestations may occur, including involvement of the lungs, skin, and joints. Classically, the diagnosis used to be made based on the creatine kinase level increase, abnormalities in electroneuromyography and presence of inflammatory infiltrates in the muscle biopsy. Recently, the importance of autoantibodies has increased, and now they may be identified in more than half of IIM patients. The continuous clinicoseropathological improvement in IIM knowledge has changed the way we see these patients and how we classify them. In the past, only polymyositis, dermatomyositis and inclusion body myopathy were described. Currently, immune-mediated necrotizing myopathy, overlap myositis and antisynthetase syndrome have been considered the most common forms of IIM in clinical practice, increasing the spectrum of classification. Patients previously considered to have polymyositis, in fact have these other forms of seropositive IIM. In this article, we reviewed the new concepts of classification, a practical way to make the diagnosis and how to plan the treatment of patients suffering from IIM.

The Location of Disease-Causing DES Variants Determines the Severity of Phenotype and the Morphology of Sarcoplasmic Aggregates.

Desmin (DES) is the main intermediate muscle filament that connects myofibrils individually and with the nucleus, sarcolemma, and organelles. Pathogenic variants of DES cause desminopathy, a disorder affecting the heart and skeletal muscles. We aimed to analyze the clinical features, morphology, and distribution of desmin aggregates in skeletal muscle biopsies of patients with desminopathy and to correlate these findings with the type and location of disease-causing DES variants. This retrospective study included 30 patients from 20 families with molecularly confirmed desminopathy from 2 neuromuscular referral centers. We identified 2 distinct patterns of desmin aggregates: well-demarcated subsarcolemmal aggregates and diffuse aggregates with poorly delimited borders. Pathogenic variants located in the 1B segment and the tail domain of the desmin molecule are more likely to present with early-onset cardiomyopathy compared to patients with variants in other segments. All patients with mutations in the 1B segment had well-demarcated subsarcolemmal aggregates, but none of the patients with variants in other desmin segments showed such histological features. We suggest that variants located in the 1B segment lead to well-shaped subsarcolemmal desmin aggregation and cause disease with more frequent cardiac manifestations. These findings will facilitate early identification of patients with potentially severe cardiac syndromes.

Effect of the COVID-19 pandemic on patients with inherited neuromuscular disorders.

BACKGROUND: The COVID-19 pandemic has brought substantial challenges for current practices in treating hereditary neuromuscular disorders (hNMDs). However, this infection has not been the only concern for these patients. Social distancing has compromised multidisciplinary assistance and physical activity, and has brought about several mental health issues. We presented a follow-up on 363 patients with hNMDs at a Brazilian tertiary center during the peak of the COVID-19 pandemic. OBJECTIVE: We aimed to show the frequency and severity of SARS-CoV-2 infection among hNMD patients and to demonstrate the effects of the pandemic on life habits, disease progression and multidisciplinary supportive care status. METHODS: Three hundred and sixty-three patients (58% male and 42% female) were followed for three months through three teleconsultations during the peak of the COVID-19 pandemic in Brazil. RESULTS: There were decreases in the numbers of patients who underwent physical, respiratory and speech therapies. For several patients, their appetite (33%) and sleep habits (25%) changed. Physical exercises and therapies were interrupted for most of the patients. They reported new onset/worsening of fatigue (17%), pain (17%), contractions (14%) and scoliosis (7%). Irritability and sleep, weight and appetite changes, and especially diminished appetite and weight loss, were more frequent in the group that reported disease worsening. There was a low COVID-19 contamination rate (0.8%), and all infected patients had a mild presentation. CONCLUSION: The isolation by itself was protective from a COVID-19 infection perspective. However, this isolation might also trigger a complex scenario with life habit changes that are associated with an unfavorable course for the NMD.

Managing intrathecal administration of nusinersen in adolescents and adults with 5q-spinal muscular atrophy and previous spinal surgery.

BACKGROUND: Spinal muscular atrophy (SMA) is a neurodegenerative disease of lower motor neurons associated with frequent occurrence of spinal deformity. Nusinersen is an antisense oligonucleotide that increases SMN protein level and is administrated by frequent intrathecal lumbar injections. Thus, spinal deformities and previous spinal surgery are important challenges for drug delivery in SMA. OBJECTIVE: To report imaging methods used for Nusinersen injection in SMA patients. METHODS: Nusinersen injection procedures in SMA types 2 and 3 patients who had previous spinal surgery were analyzed retrospectively to describe the imaging and puncture procedures, as well as the occurrence of complications. RESULTS: Nine SMA patients (14 to 50 years old) underwent 57 lumbar punctures for nusinersen injection. Six patients had no interlaminar space available; in five of them, a transforaminal approach was used, and another one underwent a surgery to open a posterior bone window for the injections. Transforaminal puncture was performed using CT scan in three cases and fluoroscopy in the other two, with a similar success rate. One patient in the transforaminal group had post-procedure radiculitis, and another one had vagal reaction (hypotension). In three cases, with preserved interlaminar space, injections were performed by posterior interlaminar puncture, and only one adverse event was reported (post-puncture headache). CONCLUSION: In SMA patients with previous spinal surgery, the use of imaging-guided intervention is necessary for administering intrathecal nusinersen. Transforaminal technique is indicated in patients for whom the interlaminar space is not available, and injections should always be guided by either CT or fluoroscopy.

Motor unit number index (MUNIX) in children and adults with 5q-spinal muscular atrophy: Variability and clinical correlations.

Spinal muscular atrophy (SMA) is a motor neuron disease associated with progressive muscle weakness and motor disability. The motor unit number index (MUNIX) is a biomarker used to assess loss of motor units in later-onset SMA patients. Twenty SMA patients (SMA types 3 and 4), aged between 7 and 41 years, were clinically evaluated through the Hammersmith Motor Functional Scale Expanded and the Spinal Muscular Atrophy-Functional Rating Scale. The patients underwent compound motor action potential (CMAP) and MUNIX studies of the right abductor pollicis brevis, abductor digiti minimi and tibialis anterior (TA) muscles. Age-matched healthy controls (n = 20) were enrolled to obtain normative CMAP and MUNIX values from the same muscles. Compared to healthy controls, SMA patients showed significant reductions in MUNIX values among all muscles studied, whereas CMAP showed reductions only in the weaker muscles (abductor digiti minimi and TA). MUNIX variability was significantly higher in the SMA group than in the control group. MUNIX variability in TA correlated with CMAP variability. Motor functional scores correlated with TA MUNIX. The MUNIX study is feasible in later-onset SMA patients, and TA MUNIX values correlate with disease severity in patients with mild motor impairment.

Electrophysiological study of neuromuscular junction in congenital myasthenic syndromes, congenital myopathies, and chronic progressive external ophthalmoplegia.

This study was designed to analyze the sensitivity, specificity, and accuracy of jitter parameters combined with repetitive nerve stimulation (RNS) in congenital myasthenic syndrome (CMS), chronic progressive external ophthalmoplegia (CPEO), and congenital myopathies (CM). Jitter was obtained with a concentric needle electrode during voluntary activation of the Orbicularis Oculi muscle in CMS (n = 21), CPEO (n = 20), and CM (n = 18) patients and in controls (n = 14). RNS (3 Hz) was performed in six different muscles for all patients (Abductor Digiti Minimi, Tibialis Anterior, upper Trapezius, Deltoideus, Orbicularis Oculi, and Nasalis). RNS was abnormal in 90.5% of CMS patients and in only one CM patient. Jitter was abnormal in 95.2% of CMS, 20% of CPEO, and 11.1% of CM patients. No patient with CPEO or CM presented a mean jitter higher than 53.6 µs or more than 30% abnormal individual jitter (> 45 µs). No patient with CPEO or CM and mild abnormal jitter values presented an abnormal decrement. Jitter and RNS assessment are valuable tools for diagnosing neuromuscular transmission abnormalities in CMS patients. A mean jitter value above 53.6 µs or the presence of more than 30% abnormal individual jitter (> 45 µs) strongly suggests CMS compared with CPEO and CM.

Clinical features of collagen VI-related dystrophies: A large Brazilian cohort.

OBJECTIVES: Collagen VI-related dystrophies (COL6-RDs) have a broad clinical spectrum and are caused by mutations in the COL6A1, COL6A2 and COL6A3 genes. Despite the clinical variability, two phenotypes are classically recognized: Bethlem myopathy (BM, milder form) and Ullrich congenital muscular dystrophy (UCMD, more severe form), with many patients presenting an intermediate phenotype. In this work, we present clinical and genetic data from 28 patients (27 families), aged 6-38 years (mean of 16.96 years), with COL6-RDs. PATIENTS AND METHODS: Clinical, muscle histology and genetic data are presented. COL6A1, COL6A2 and COL6A3 genes were analyzed by next-generation sequencing (NGS). RESULTS: Homozygous or heterozygous variants were found in COL6A1 (12 families), COL6A2 (12 families) and COL6A3 (3 families). Patients with the severe UCMD phenotype (three cases) had a homogeneous clinical picture characterized by neonatal onset of manifestations, no gait acquisition and a stable course, but with severe respiratory involvement. Most of the patients with the mild UCMD phenotype had neonatal onset of manifestations (88.8 %), delayed motor development (66.6 %), slowly progressive course, pulmonary involvement (55.5 %) and loss of the walking capacity before the age of 10 (66.6 %). In the intermediate group (nine patients), some children had neonatal onset of manifestations (44.5 %) and delayed motor development (88.9 %); but all of them achieved the ability to walk and were still ambulatory. Some patients that had the BM phenotype presented neonatal manifestations (57.1 %); however, all of them had normal motor development and normal pulmonary function. Only one patient from the group of BM lost the walking capacity during the evolution of the disease. Other frequent findings observed in all groups were joint retractions, spinal deformities, distal hyperextensibility, congenital hip dislocation and keloid formation. CONCLUSION: COL6-RDs present variable clinical manifestations, but common findings are helpful for the clinical suspicion. NGS is a valuable approach for diagnosis, providing useful information for the genetic counseling of families.

Intragenic variants in the SMN1 gene determine the clinical phenotype in 5q spinal muscular atrophy.

OBJECTIVE: The aim of the study was to report the proportion of homozygous and compound heterozygous variants in the survival motor neuron 1 (SMN1) gene in a large population of patients with spinal muscular atrophy (SMA) and to correlate the severity of the disease with the presence of specific intragenic variants in SMN1 and with the SMN2 copy number. METHODS: Four hundred fifty Brazilian patients with SMA were included in a retrospective study, and clinical data were analyzed compared with genetic data; the SMN2 copy number was obtained by multiplex ligation-dependent probe amplification and pathogenic variants in SMN1 by next-generation sequencing. RESULTS: Four hundred two patients (89.3%) presented homozygous exon 7-SMN1 deletion, and 48 (10.7%) were compound heterozygous for the common deletion in one allele and a point mutation in the other allele. Recurrent variants in exons 3 and 6 (c.460C>T, c.770_780dup and c.734_735insC) accounted for almost 80% of compound heterozygous patients. Another recurrent pathogenic variant was c.5C>G at exon 1. Patients with c.770_780dup and c.734_735insC had a clinical phenotype correlated with SMN2 copy number, whereas the variants c.460C>T and c.5C>G determined a milder phenotype independently of the SMN2 copies. CONCLUSIONS: Patients with specific pathogenic variants (c.460C>T and c.5C>G) presented a milder phenotype, and the SMN2 copy number did not correlate with disease severity in this group.

Neurological consultations and diagnoses in a large, dedicated COVID-19 university hospital.

BACKGROUND: More than one-third of COVID-19 patients present neurological symptoms ranging from anosmia to stroke and encephalopathy. Furthermore, pre-existing neurological conditions may require special treatment and may be associated with worse outcomes. Notwithstanding, the role of neurologists in COVID-19 is probably underrecognized. OBJECTIVE: The aim of this study was to report the reasons for requesting neurological consultations by internists and intensivists in a COVID-19-dedicated hospital. METHODS: This retrospective study was carried out at Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil, a 900-bed COVID-19 dedicated center (including 300 intensive care unit beds). COVID-19 diagnosis was confirmed by SARS-CoV-2-RT-PCR in nasal swabs. All inpatient neurology consultations between March 23rd and May 23rd, 2020 were analyzed. Neurologists performed the neurological exam, assessed all available data to diagnose the neurological condition, and requested additional tests deemed necessary. Difficult diagnoses were established in consensus meetings. After diagnosis, neurologists were involved in the treatment. RESULTS: Neurological consultations were requested for 89 out of 1,208 (7.4%) inpatient COVID admissions during that period. Main neurological diagnoses included: encephalopathy (44.4%), stroke (16.7%), previous neurological diseases (9.0%), seizures (9.0%), neuromuscular disorders (5.6%), other acute brain lesions (3.4%), and other mild nonspecific symptoms (11.2%). CONCLUSIONS: Most neurological consultations in a COVID-19-dedicated hospital were requested for severe conditions that could have an impact on the outcome. First-line doctors should be able to recognize neurological symptoms; neurologists are important members of the medical team in COVID-19 hospital care.

Clinical variability of early-onset congenital myasthenic syndrome due to biallelic RAPSN mutations in Brazil.

Mutations in RAPSN are an important cause of congenital myasthenic syndrome (CMS), leading to endplate acetylcholine receptor deficiency. We present three RAPSN early-onset CMS patients (from a Brazilian cohort of 61 CMS patients). Patient 1 and patient 2 harbor the mutation p.N88K in homozygosity, while patient 3 harbors p.N88K in compound heterozygosity with another pathogenic variant (p.V165M; c.493G ≥ A). At onset, patient 3 presented with more severe symptoms compared to the other two, showing generalized weakness and repeated episodes of respiratory failure in the first years of life. During adolescence, she became gradually less symptomatic and does not require medication anymore, presenting better long-term outcomes than patients 1 and 2. This case series illustrates the variability of RAPSN early-onset CMS, with patient 3, despite severe onset, revealing an almost complete reversal of myasthenic symptoms, not limited to apneic episodes. Moreover, it suggests that RAPSN CMS may be underdiagnosed in non-European countries.

A common CHRNE mutation in Brazilian patients with congenital myasthenic syndrome.

The most common causes of congenital myasthenic syndromes (CMS) are CHRNE mutations, and some pathogenic allelic variants in this gene are especially frequent in certain ethnic groups. In the southern region of Brazil, a study found the c.130dupG CHRNE mutation in up to 33% of families with CMS. Here, we aimed to verify the frequency of this mutation among individuals with CMS in a larger cohort of CMS patients from different areas of Brazil and to characterize clinical features of these patients. Eighty-four patients with CMS, from 72 families, were clinically evaluated and submitted to direct sequencing of the exon 2 of CHRNE. The c.130dupG mutation was found in 32 patients (23 families), with 26 patients (19 families, 26.3%) in homozygosis, confirming its high prevalence in different regions of Brazil. Among the homozygous patients, the following characteristics were frequent: onset of symptoms before 2 years of age (92.3%), little functional restriction (92.3%), fluctuating symptoms (100%), ocular muscle impairment (96.1%), ptosis (100%), limb weakness (88.4%), response to pyridostigmine (100%), facial involvement (77%), and bulbar symptoms (70.8%). The pretest probability of finding at least one allele harbouring the c.130dupG mutation was 38.1%. Selecting only patients with impaired eye movement together with limb weakness and improvement with pyridostigmine, the probability increases to 72.2%. This clinical pre-selection of patients is likely a useful tool for regions where CHRNE mutations have a founder effect. In conclusion, the CHRNE mutation c.130dupG leads to fairly benign natural course of the disease with relative homogeneity.

Inflammatory myopathies: an update for neurologists / Miopatias inflamatórias: uma atualização para neurologistas

ABSTRACT Idiopathic inflammatory myopathies (IIM) are a heterogenous group of treatable myopathies. Patients present mainly to the rheumatologist and neurologists, complaining of acute or subacute onset of proximal weakness. Extramuscular manifestations may occur, including involvement of the lungs, skin, and joints. Classically, the diagnosis used to be made based on the creatine kinase level increase, abnormalities in electroneuromyography and presence of inflammatory infiltrates in the muscle biopsy. Recently, the importance of autoantibodies has increased, and now they may be identified in more than half of IIM patients. The continuous clinicoseropathological improvement in IIM knowledge has changed the way we see these patients and how we classify them. In the past, only polymyositis, dermatomyositis and inclusion body myopathy were described. Currently, immune-mediated necrotizing myopathy, overlap myositis and antisynthetase syndrome have been considered the most common forms of IIM in clinical practice, increasing the spectrum of classification. Patients previously considered to have polymyositis, in fact have these other forms of seropositive IIM. In this article, we reviewed the new concepts of classification, a practical way to make the diagnosis and how to plan the treatment of patients suffering from IIM.

RESUMO As miopatias inflamatórias idiopáticas (MII) são um grupo heterogêneo de miopatias tratáveis. Os pacientes procuram principalmente o reumatologista e o neurologista, queixando-se de início agudo ou subagudo de fraqueza proximal. Manifestações extramusculares podem ocorrer, incluindo envolvimento dos pulmões, pele e articulações. Classicamente, o diagnóstico era feito com base na elevação dos níveis de creatina quinase, anormalidades na eletroneuromiografia e presença de infiltrados inflamatórios na biópsia muscular. Recentemente, a importância dos autoanticorpos aumentou, e agora eles podem ser identificados em mais da metade dos pacientes com MII. A contínua melhora clínico-soropatológica no conhecimento do MII mudou a forma como vemos esses pacientes e como os classificamos. No passado, apenas polimiosite, dermatomiosite e miopatia por corpos de inclusão eram descritas. Atualmente, a miopatia necrosante imunomediada, a miosite de sobreposição e a síndrome antissintetase têm sido consideradas as formas mais comuns de MII na prática clínica, aumentando o espectro de classificação. Pacientes previamente considerados como portadores de polimiosite, na verdade, têm uma dessas outras formas de MII soropositivas. Neste artigo, revisamos os novos conceitos de classificação, uma forma prática de fazer o diagnóstico e como planejar o tratamento de pacientes que sofrem de MII.

Effect of the COVID-19 pandemic on patients with inherited neuromuscular disorders / Efeito da pandemia do COVID-19 em pacientes com doenças neuromusculares hereditárias

ABSTRACT Background The COVID-19 pandemic has brought substantial challenges for current practices in treating hereditary neuromuscular disorders (hNMDs). However, this infection has not been the only concern for these patients. Social distancing has compromised multidisciplinary assistance and physical activity, and has brought about several mental health issues. We presented a follow-up on 363 patients with hNMDs at a Brazilian tertiary center during the peak of the COVID-19 pandemic. Objective We aimed to show the frequency and severity of SARS-CoV-2 infection among hNMD patients and to demonstrate the effects of the pandemic on life habits, disease progression and multidisciplinary supportive care status. Methods Three hundred and sixty-three patients (58% male and 42% female) were followed for three months through three teleconsultations during the peak of the COVID-19 pandemic in Brazil. Results There were decreases in the numbers of patients who underwent physical, respiratory and speech therapies. For several patients, their appetite (33%) and sleep habits (25%) changed. Physical exercises and therapies were interrupted for most of the patients. They reported new onset/worsening of fatigue (17%), pain (17%), contractions (14%) and scoliosis (7%). Irritability and sleep, weight and appetite changes, and especially diminished appetite and weight loss, were more frequent in the group that reported disease worsening. There was a low COVID-19 contamination rate (0.8%), and all infected patients had a mild presentation. Conclusion The isolation by itself was protective from a COVID-19 infection perspective. However, this isolation might also trigger a complex scenario with life habit changes that are associated with an unfavorable course for the NMD.

RESUMO Antecedentes: A Pandemia por COVID-19 tem trazido desafios subtanciais para a prática clínica no tratamento das doenças neuromusculares hereditárias (DNMh). A infecção não tem sido a única preocupação para os pacientes. O distanciamento social tem comprometido a assistência multidisciplinar, atividade física e tem trazido problemas mentais em decorrência do próprio isolamento. Nós apresentamos aqui um seguimento de 363 pacientes com DNMh de um centro terciário Brasileiro durante o pico da Pandemia de Covid-19. Objetivos: Mostrar a frequência e gravidade da infecção por Sars-Cov-2 em pacientes com DNMh e demonstrar os efeitos da pandemia nos hábitos de vida, na progressão da doença e no cuidado multidisciplinary. Métodos Trezentos e sessenta e três pacientes (58% homens and 42% mulheres) foram acompanhados por 3 meses através de 3 teleconsultas durante o pico da Pandemia de Covid-19 no Brasil. Resultados Houve um decréscimo no número de pacientes que faziam terapia física, respiratória e fonoaudiológica. Em muitos pacientes, o apetite (33%) e hábitos do sono (25%) se alteraram. Exercícios físicos e terapias foram interrompidas pela maioria dos pacientes. Physical exercises and therapies were interrupted for most of the patients. Eles relataram piora ou aparecimento de fadiga (17%), dor (17%), retrações (14%), e escoliose (7%). Irritabilidade, mudanças no sono, peso e apetite, sendo principalmente diminuição do apetite e peso foram mais frequentemente encontrados em pacientes que apresentaram piora clinica da doença. Houve uma baixa taxa de contaminação por Covid-19 (0.8%), e todos os pacientes infectado apresentaram quadro clinico leve. Conclusão O isolamento por si só se mostrou protetor na perspectiva de infecção por Covid-19, mas pode desencadear um cenário complexo com mudanças nos hábitos de vida e curso desfavorável da doença de base.