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2.
J Neurol ; 270(12): 5849-5865, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37603075

ABSTRACT

BACKGROUND: The diagnosis of patients with mutations in the VCP gene can be complicated due to their broad phenotypic spectrum including myopathy, motor neuron disease and peripheral neuropathy. Muscle MRI guides the diagnosis in neuromuscular diseases (NMDs); however, comprehensive muscle MRI features for VCP patients have not been reported so far. METHODS: We collected muscle MRIs of 80 of the 255 patients who participated in the "VCP International Study" and reviewed the T1-weighted (T1w) and short tau inversion recovery (STIR) sequences. We identified a series of potential diagnostic MRI based characteristics useful for the diagnosis of VCP disease and validated them in 1089 MRIs from patients with other genetically confirmed NMDs. RESULTS: Fat replacement of at least one muscle was identified in all symptomatic patients. The most common finding was the existence of patchy areas of fat replacement. Although there was a wide variability of muscles affected, we observed a common pattern characterized by the involvement of periscapular, paraspinal, gluteal and quadriceps muscles. STIR signal was enhanced in 67% of the patients, either in the muscle itself or in the surrounding fascia. We identified 10 diagnostic characteristics based on the pattern identified that allowed us to distinguish VCP disease from other neuromuscular diseases with high accuracy. CONCLUSIONS: Patients with mutations in the VCP gene had common features on muscle MRI that are helpful for diagnosis purposes, including the presence of patchy fat replacement and a prominent involvement of the periscapular, paraspinal, abdominal and thigh muscles.


Subject(s)
Muscle, Skeletal , Muscular Diseases , Humans , Muscle, Skeletal/diagnostic imaging , Muscle, Skeletal/pathology , Muscular Diseases/diagnostic imaging , Muscular Diseases/genetics , Muscular Diseases/pathology , Mutation/genetics , Magnetic Resonance Imaging/methods , Valosin Containing Protein/genetics
3.
Neurol Genet ; 9(5): e200093, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37588275

ABSTRACT

Background and Objectives: Pathogenic variants in the valosin-containing protein (VCP) gene cause a phenotypically heterogeneous disorder that includes myopathy, motor neuron disease, Paget disease of the bone, frontotemporal dementia, and parkinsonism termed multisystem proteinopathy. This hallmark pleiotropy makes the classification of novel VCP variants challenging. This retrospective study describes and assesses the effect of 19 novel or nonpreviously clinically characterized VCP variants identified in 28 patients (26 unrelated families) in the retrospective VCP International Multicenter Study. Methods: A 6-item clinical score was developed to evaluate the phenotypic level of evidence to support the pathogenicity of the novel variants. Each item is allocated a value, a score ranging from 0.5 to 5.5 points. A receiver-operating characteristic curve was used to identify a cutoff value of 3 to consider a variant as high likelihood disease associated. The scoring system results were confronted with results of in vitro ATPase activity assays and with in silico analysis. Results: All variants were missense, except for one small deletion-insertion, 18 led to amino acid changes within the N and D1 domains, and 13 increased the enzymatic activity. The clinical score coincided with the functional studies in 17 of 19 variants and with the in silico analysis in 12 of 19. For 12 variants, the 3 predictive tools agreed, and for 7 variants, the predictive tools disagreed. The pooled data supported the pathogenicity of 13 of 19 novel VCP variants identified in the study. Discussion: This study provides data to support pathogenicity of 14 of 19 novel VCP variants and provides guidance for clinicians in the evaluation of novel variants in the VCP gene.

4.
Neuropathol Appl Neurobiol ; 49(4): e12918, 2023 08.
Article in English | MEDLINE | ID: mdl-37317811

ABSTRACT

AIMS: Dynamin-2 is a large GTPase, a member of the dynamin superfamily that regulates membrane remodelling and cytoskeleton dynamics. Mutations in the dynamin-2 gene (DNM2) cause autosomal dominant centronuclear myopathy (CNM), a congenital neuromuscular disorder characterised by progressive weakness and atrophy of the skeletal muscles. Cognitive defects have been reported in some DNM2-linked CNM patients suggesting that these mutations can also affect the central nervous system (CNS). Here we studied how a dynamin-2 CNM-causing mutation influences the CNS function. METHODS: Heterozygous mice harbouring the p.R465W mutation in the dynamin-2 gene (HTZ), the most common causing autosomal dominant CNM, were used as disease model. We evaluated dendritic arborisation and spine density in hippocampal cultured neurons, analysed excitatory synaptic transmission by electrophysiological field recordings in hippocampal slices, and evaluated cognitive function by performing behavioural tests. RESULTS: HTZ hippocampal neurons exhibited reduced dendritic arborisation and lower spine density than WT neurons, which was reversed by transfecting an interference RNA against the dynamin-2 mutant allele. Additionally, HTZ mice showed defective hippocampal excitatory synaptic transmission and reduced recognition memory compared to the WT condition. CONCLUSION: Our findings suggest that the dynamin-2 p.R465W mutation perturbs the synaptic and cognitive function in a CNM mouse model and support the idea that this GTPase plays a key role in regulating neuronal morphology and excitatory synaptic transmission in the hippocampus.


Subject(s)
Dynamin II , Myopathies, Structural, Congenital , Animals , Mice , Disease Models, Animal , Dynamin II/genetics , Dynamin II/metabolism , Muscle, Skeletal/metabolism , Mutation , Myopathies, Structural, Congenital/genetics , Neurons/metabolism , Synaptic Transmission
5.
Article in English | MEDLINE | ID: mdl-35896379

ABSTRACT

BACKGROUND: Valosin-containing protein (VCP) disease, caused by mutations in the VCP gene, results in myopathy, Paget's disease of bone (PBD) and frontotemporal dementia (FTD). Natural history and genotype-phenotype correlation data are limited. This study characterises patients with mutations in VCP gene and investigates genotype-phenotype correlations. METHODS: Descriptive retrospective international study collecting clinical and genetic data of patients with mutations in the VCP gene. RESULTS: Two hundred and fifty-five patients (70.0% males) were included in the study. Mean age was 56.8±9.6 years and mean age of onset 45.6±9.3 years. Mean diagnostic delay was 7.7±6 years. Symmetric lower limb weakness was reported in 50% at onset progressing to generalised muscle weakness. Other common symptoms were ventilatory insufficiency 40.3%, PDB 28.2%, dysautonomia 21.4% and FTD 14.3%. Fifty-seven genetic variants were identified, 18 of these no previously reported. c.464G>A (p.Arg155His) was the most frequent variant, identified in the 28%. Full time wheelchair users accounted for 19.1% with a median time from disease onset to been wheelchair user of 8.5 years. Variant c.463C>T (p.Arg155Cys) showed an earlier onset (37.8±7.6 year) and a higher frequency of axial and upper limb weakness, scapular winging and cognitive impairment. Forced vital capacity (FVC) below 50% was as risk factor for being full-time wheelchair user, while FVC <70% and being a full-time wheelchair user were associated with death. CONCLUSION: This study expands the knowledge on the phenotypic presentation, natural history, genotype-phenotype correlations and risk factors for disease progression of VCP disease and is useful to improve the care provided to patient with this complex disease.

6.
Genes (Basel) ; 13(6)2022 06 16.
Article in English | MEDLINE | ID: mdl-35741838

ABSTRACT

Hereditary myopathies are a group of genetically determined muscle disorders comprising more than 300 entities. In Chile, there are no specific registries of the distinct forms of these myopathies. We now report the genetic findings of a series of Chilean patients presenting with limb-girdle muscle weakness of unknown etiology. Eighty-two patients were explored using high-throughput sequencing approaches with neuromuscular gene panels, establishing a definite genetic diagnosis in 49 patients (59.8%) and a highly probable genetic diagnosis in eight additional cases (9.8%). The most frequent causative genes identified were DYSF and CAPN3, accounting for 22% and 8.5% of the cases, respectively, followed by DMD (4.9%) and RYR1 (4.9%). The remaining 17 causative genes were present in one or two cases only. Twelve novel variants were identified. Five patients (6.1%) carried a variant of uncertain significance in genes partially matching the clinical phenotype. Twenty patients (24.4%) did not carry a pathogenic or likely pathogenic variant in the phenotypically related genes, including five patients (6.1%) presenting an autoimmune neuromuscular disorder. The relative frequency of the different forms of myopathy in Chile is like that of other series reported from different regions of the world with perhaps a relatively higher incidence of dysferlinopathy.


Subject(s)
Muscular Diseases , Muscular Dystrophies, Limb-Girdle , Chile , Genetic Profile , Humans , Muscle Weakness/genetics , Muscular Dystrophies, Limb-Girdle/epidemiology , Muscular Dystrophies, Limb-Girdle/genetics
7.
Neuromuscul Disord ; 32(8): 687-691, 2022 08.
Article in English | MEDLINE | ID: mdl-35688744

ABSTRACT

Tropomyosin 3 (TPM3) gene mutations associate with autosomal dominant and recessive nemaline myopathy 1 (NEM1), congenital fiber type disproportion myopathy (CFTD) and cap myopathy (CAPM1), and a combination of caps and nemaline bodies. We report on a 47-year-old man with polyglobulia, restricted vital capacity and mild apnea hypopnea syndrome, requiring noninvasive ventilation. Physical assessment revealed bilateral ptosis and facial paresis, with high arched palate and retrognathia; global hypotonia and diffuse axial weakness, including neck and upper and lower limb girdle and foot dorsiflexion weakness. Whole body MRI showed a diffuse fatty replacement with an unspecific pattern. A 122 gene NGS neuromuscular disorders panel revealed the heterozygous VUS c.709G>A (p.Glu237Lys) on exon 8 of TMP3. A deltoid muscle biopsy showed a novel histological pattern combining fiber type disproportion and caps. Our findings support the pathogenicity of the novel TPM3 variant and widen the phenotypic gamut of TMP3-related congenital myopathy.


Subject(s)
Myopathies, Nemaline , Myopathies, Structural, Congenital , Humans , Male , Middle Aged , Muscle, Skeletal/diagnostic imaging , Muscle, Skeletal/pathology , Mutation , Myopathies, Nemaline/genetics , Myopathies, Structural, Congenital/genetics , Myopathies, Structural, Congenital/pathology , Tropomyosin/genetics
10.
PLoS One ; 15(11): e0242443, 2020.
Article in English | MEDLINE | ID: mdl-33216776

ABSTRACT

Idiopathic Inflammatory Myopathies (IIMs) have been studied within the framework of autoimmune diseases where skeletal muscle appears to have a passive role in the illness. However, persiting weakness even after resolving inflammation raises questions about the role that skeletal muscle plays by itself in these diseases. "Non-immune mediated" hypotheses have arisen to consider inner skeletal muscle cell processes as trigger factors in the clinical manifestations of IIMs. Alterations in oxidative phosphorylation, ATP production, calcium handling, autophagy, endoplasmic reticulum stress, among others, have been proposed as alternative cellular pathophysiological mechanisms. In this study, we used skeletal muscle-derived cells, from healthy controls and IIM patients to determine mitochondrial function and mitochondrial ability to adapt to a metabolic stress when deprived of glucose. We hypothesized that mitochondria would be dysfunctional in IIM samples, which was partially true in normal glucose rich growing medium as determined by oxygen consumption rate. However, in the glucose-free and galactose supplemented condition, a medium that forced mitochondria to function, IIM cells increased their respiration, reaching values matching normal derived cells. Unexpectedly, cell death significantly increased in IIM cells under this condition. Our findings show that mitochondria in IIM is functional and the decrease respiration observed is part of an adaptative response to improve survival. The increased metabolic function obtained after forcing IIM cells to rely on mitochondrial synthesized ATP is detrimental to the cell's viability. Thus, therapeutic interventions that activate mitochondria, could be detrimental in IIM cell physiology, and must be avoided in patients with IIM.


Subject(s)
Apoptosis/physiology , Mitochondria/metabolism , Muscle, Skeletal/metabolism , Myoblasts/pathology , Myositis/pathology , Adenosine Triphosphate/analysis , Aged , Autoantibodies/immunology , Autoimmune Diseases/pathology , Cells, Cultured , Endoplasmic Reticulum Stress/physiology , Female , Humans , Male , Membrane Potential, Mitochondrial/physiology , Middle Aged , Oxidative Phosphorylation , Oxidative Stress/physiology , Reactive Oxygen Species/metabolism
11.
Neuromuscul Disord ; 30(6): 503-509, 2020 06.
Article in English | MEDLINE | ID: mdl-32518057

ABSTRACT

Immune-mediated necrotizing myopathy with antibodies against 3-hydroxy-3-methylglutaryl-coenzyme A reductase is a subgroup of idiopathic inflammatory myopathies mainly described in adults and requiring long term immunomodulatory therapy for remission. Pediatric patients have been reported as small series or sporadic cases. We report an eight-year-old girl with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase myopathy, presenting with subacute proximal limb weakness, high creatine kinase and a muscle biopsy displaying necrotizing pattern, initially diagnosed as limb-girdle muscular dystrophy, but subsequently negative genetic testing. A noteworthy spontaneous improvement in her weakness suggested the possibility of an acquired autoimmune myopathy, confirmed by positive testing of anti-HMGCR antibodies titers. After four years of follow-up, she maintains normal strength with high levels of anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibody. This patient shows that spontaneous fluctuations and spontaneous long-lasting symptomatic remission can occur in patients with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase myopathy. Some patients could present a wane and wax clinical course, an important aspect when assessing response to therapy.


Subject(s)
Autoimmune Diseases , Hydroxymethylglutaryl CoA Reductases/immunology , Myositis , Autoantibodies , Autoimmune Diseases/blood , Autoimmune Diseases/immunology , Autoimmune Diseases/pathology , Autoimmune Diseases/physiopathology , Child , Female , Humans , Myositis/blood , Myositis/immunology , Myositis/pathology , Myositis/physiopathology , Remission, Spontaneous
12.
Int J Mol Sci ; 21(12)2020 Jun 16.
Article in English | MEDLINE | ID: mdl-32560255

ABSTRACT

Dysferlinopathy is an autosomal recessive muscular dystrophy resulting from mutations in the dysferlin gene. Absence of dysferlin in the sarcolemma and progressive muscle wasting are hallmarks of this disease. Signs of oxidative stress have been observed in skeletal muscles of dysferlinopathy patients, as well as in dysferlin-deficient mice. However, the contribution of the redox imbalance to this pathology and the efficacy of antioxidant therapy remain unclear. Here, we evaluated the effect of 10 weeks diet supplementation with the antioxidant agent N-acetylcysteine (NAC, 1%) on measurements of oxidative damage, antioxidant enzymes, grip strength and body mass in 6 months-old dysferlin-deficient Bla/J mice and wild-type (WT) C57 BL/6 mice. We found that quadriceps and gastrocnemius muscles of Bla/J mice exhibit high levels of lipid peroxidation, protein carbonyls and superoxide dismutase and catalase activities, which were significantly reduced by NAC supplementation. By using the Kondziela's inverted screen test, we further demonstrated that NAC improved grip strength in dysferlin deficient animals, as compared with non-treated Bla/J mice, without affecting body mass. Together, these results indicate that this antioxidant agent improves skeletal muscle oxidative balance, as well as muscle strength and/or resistance to fatigue in dysferlin-deficient animals.


Subject(s)
Acetylcysteine/administration & dosage , Antioxidants/administration & dosage , Muscle, Skeletal/drug effects , Muscular Dystrophies, Limb-Girdle/diet therapy , Acetylcysteine/pharmacology , Animals , Antioxidants/pharmacology , Body Mass Index , Disease Models, Animal , Humans , Lipid Peroxidation/drug effects , Mice , Muscle Strength/drug effects , Muscle, Skeletal/metabolism , Muscle, Skeletal/physiopathology , Muscular Dystrophies, Limb-Girdle/metabolism , Muscular Dystrophies, Limb-Girdle/physiopathology , Oxidative Stress/drug effects , Protein Carbonylation/drug effects , Superoxide Dismutase/metabolism , Treatment Outcome
13.
Biochim Biophys Acta Mol Basis Dis ; 1866(8): 165800, 2020 08 01.
Article in English | MEDLINE | ID: mdl-32305450

ABSTRACT

Dysferlinopathy is a genetic human disease caused by mutations in the gene that encodes the dysferlin protein (DYSF). Dysferlin is believed to play a relevant role in cell membrane repair. However, in dysferlin-deficient (blAJ) mice (a model of dysferlinopathies) the recovery of the membrane resealing function by means of the expression of a mini-dysferlin does not arrest progressive muscular damage, suggesting the participation of other unknown pathogenic mechanisms. Here, we show that proteins called connexins 39, 43 and 45 (Cx39, Cx43 and Cx45, respectively) are expressed by blAJ myofibers and form functional hemichannels (Cx HCs) in the sarcolemma. At rest, Cx HCs increased the sarcolemma permeability to small molecules and the intracellular Ca2+ signal. In addition, skeletal muscles of blAJ mice showed lipid accumulation and lack of dysferlin immunoreactivity. As sign of extensive damage and atrophy, muscles of blAJ mice presented elevated numbers of myofibers with internal nuclei, increased number of myofibers with reduced cross-sectional area and elevated creatine kinase activity in serum. In agreement with the extense muscle damage, mice also showed significantly low motor performance. We generated blAJ mice with myofibers deficient in Cx43 and Cx45 expression and found that all above muscle and systemic alterations were absent, indicating that these two Cxs play a critical role in a novel pathogenic mechanism of dysfernolophaties, which is discussed herein. Therefore, Cx HCs could constitute an attractive target for pharmacologic treatment of dyferlinopathies.


Subject(s)
Connexin 43/genetics , Connexins/genetics , Dysferlin/genetics , Muscular Dystrophies, Limb-Girdle/genetics , Muscular Dystrophies, Limb-Girdle/prevention & control , Myofibrils/genetics , Animals , Calcium/metabolism , Connexin 43/deficiency , Connexins/deficiency , Creatine Kinase/blood , Creatine Kinase/genetics , Disease Models, Animal , Dysferlin/deficiency , Gene Expression , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Muscular Dystrophies, Limb-Girdle/metabolism , Muscular Dystrophies, Limb-Girdle/pathology , Mutation , Myofibrils/metabolism , Myofibrils/pathology , Permeability , Physical Conditioning, Animal , Rotarod Performance Test , Sarcolemma/metabolism
14.
Orphanet J Rare Dis ; 15(1): 11, 2020 01 13.
Article in English | MEDLINE | ID: mdl-31931849

ABSTRACT

BACKGROUND: Limb-girdle muscular dystrophy (LGMD) is a group of neuromuscular disorders of heterogeneous genetic etiology with more than 30 directly related genes. LGMD is characterized by progressive muscle weakness involving the shoulder and pelvic girdles. An important differential diagnosis among patients presenting with proximal muscle weakness (PMW) is late-onset Pompe disease (LOPD), a rare neuromuscular glycogen storage disorder, which often presents with early respiratory insufficiency in addition to PMW. Patients with PMW, with or without respiratory symptoms, were included in this study of Latin American patients to evaluate the profile of variants for the included genes related to LGMD recessive (R) and LOPD and the frequency of variants in each gene among this patient population. RESULTS: Over 20 institutions across Latin America (Brazil, Argentina, Peru, Ecuador, Mexico, and Chile) enrolled 2103 individuals during 2016 and 2017. Nine autosomal recessive LGMDs and Pompe disease were investigated in a 10-gene panel (ANO5, CAPN3, DYSF, FKRP, GAA, SGCA, SGCB, SGCD, SGCG, TCAP) based on reported disease frequency in Latin America. Sequencing was performed with Illumina's NextSeq500 and variants were classified according to ACMG guidelines; pathogenic and likely pathogenic were treated as one category (P) and variants of unknown significance (VUS) are described. Genetic variants were identified in 55.8% of patients, with 16% receiving a definitive molecular diagnosis; 39.8% had VUS. Nine patients were identified with Pompe disease. CONCLUSIONS: The results demonstrate the effectiveness of this targeted genetic panel and the importance of including Pompe disease in the differential diagnosis for patients presenting with PMW.


Subject(s)
Glycogen Storage Disease Type II/metabolism , Glycogen Storage Disease Type II/pathology , High-Throughput Nucleotide Sequencing/methods , Muscle Weakness/metabolism , Muscular Dystrophies, Limb-Girdle/metabolism , Muscular Dystrophies, Limb-Girdle/pathology , Adolescent , Adult , Brazil , Female , Humans , Latin America , Male , Mexico , Middle Aged , Muscle Weakness/pathology , Mutation/genetics , Sequence Analysis, DNA , Young Adult
15.
Arq Neuropsiquiatr ; 77(7): 470-477, 2019 07 29.
Article in English | MEDLINE | ID: mdl-31365638

ABSTRACT

METHODS: Spinal muscular atrophy (SMA) has gained much attention in the last few years because of the approval of the first intrathecal treatment for this neurodegenerative disease. Latin America needs to develop the demographics of SMA, timely access to diagnosis, and appropriate following of the standards of care recommendations for patients. These are essential steps to guide health policies. This was a descriptive study of a cohort of SMA patients from all over Chile. We analyzed the clinical, motor functional, and social data, as well as the care status of nutritional, respiratory and skeletal conditions. We also measured the SMN2 copy number in this population. RESULTS: We recruited 92 patients: 50 male; 23 SMA type-1, 36 SMA type-2 and 33 SMA type-3. The median age at genetic diagnosis was 5, 24 and 132 months. We evaluated the SMN2 copy number in 57 patients. The SMA type-1 patients were tracheostomized and fed by gastrostomy in a 69.6 % of cases, 65% of SMA type-2 patients received nocturnal noninvasive ventilation, and 37% of the whole cohort underwent scoliosis surgery. CONCLUSION: Ventilatory care for SMA type-1 is still based mainly on tracheostomy. This Chilean cohort of SMA patients had timely access to genetic diagnosis, ventilatory assistance, nutritional support, and scoliosis surgery. In this series, SMA type-1 is underrepresented, probably due to restrictions in access to early diagnosis and the high and early mortality rate.


Subject(s)
Neurodegenerative Diseases/diagnosis , Spinal Muscular Atrophies of Childhood/diagnosis , Adolescent , Adult , Biopsy , Child , Chile/epidemiology , Cohort Studies , Electromyography , Female , Genetic Predisposition to Disease , Genotype , Humans , Infant , Infant, Newborn , Male , Neurodegenerative Diseases/mortality , Neurodegenerative Diseases/therapy , Phenotype , Prevalence , Residence Characteristics , Respiration, Artificial , Scoliosis/surgery , Socioeconomic Factors , Spinal Muscular Atrophies of Childhood/mortality , Spinal Muscular Atrophies of Childhood/therapy , Young Adult
16.
Arq. neuropsiquiatr ; 77(7): 470-477, July 2019. tab, graf
Article in English | LILACS | ID: biblio-1011362

ABSTRACT

ABSTRACT Spinal muscular atrophy (SMA) has gained much attention in the last few years because of the approval of the first intrathecal treatment for this neurodegenerative disease. Latin America needs to develop the demographics of SMA, timely access to diagnosis, and appropriate following of the standards of care recommendations for patients. These are essential steps to guide health policies. Methods This was a descriptive study of a cohort of SMA patients from all over Chile. We analyzed the clinical, motor functional, and social data, as well as the care status of nutritional, respiratory and skeletal conditions. We also measured the SMN2 copy number in this population. Results We recruited 92 patients: 50 male; 23 SMA type-1, 36 SMA type-2 and 33 SMA type-3. The median age at genetic diagnosis was 5, 24 and 132 months. We evaluated the SMN2 copy number in 57 patients. The SMA type-1 patients were tracheostomized and fed by gastrostomy in a 69.6 % of cases, 65% of SMA type-2 patients received nocturnal noninvasive ventilation, and 37% of the whole cohort underwent scoliosis surgery. Conclusion Ventilatory care for SMA type-1 is still based mainly on tracheostomy. This Chilean cohort of SMA patients had timely access to genetic diagnosis, ventilatory assistance, nutritional support, and scoliosis surgery. In this series, SMA type-1 is underrepresented, probably due to restrictions in access to early diagnosis and the high and early mortality rate.


La Atrofia Muscular Espinal (AME) ha concitado mucha atención en los últimos 2 años debido a la aprobación del primer tratamiento intratecal para esta enfermedad neurodegenerativa. América Latina necesita desarrollar la demografía de AME, un acceso oportuno al diagnóstico y un seguimiento apropiado de los pacientes que incorporen los estándares de atención recomendados por expertos. Estos son pasos esenciales para orientar las futuras políticas de salud en esta enfermedad. Métodos Este es un estudio descriptivo de una cohorte de pacientes con AME de todo el país. Se analizaron los datos clínicos, motores, funcionales, sociales y el estado nutricional, respiratorio y esquelético de los pacientes. También medimos el número de copias del gen SMN2 en esta población. Resultados se reclutaron 92 pacientes, 50 varones; 23 AME tipo 1, 36 AME tipo 2 y 33 AME tipo 3. La edad media al diagnóstico genético fue de 5, 24 y 132 meses respectivamente. Evaluamos el número de copias de SMN2 en 57 pacientes. Un 69,6% de los pacientes con AME tipo 1 estaban traqueostomízados y gastrostomizados , un 65% de los pacientes con AME tipo 2 usaban ventilación nocturna no invasiva y el 37% de toda la cohorte presentaba una cirugía de escoliosis. Conclusión Esta cohorte chilena de pacientes con AME tuvo acceso oportuno al diagnóstico genético, asistencia ventilatoria, apoyo nutricional y cirugía de escoliosis, sin embargo, la atención ventilatoria para AME tipo 1 continúa aun basándose principalmente en la traqueostomía. En esta serie, AME tipo 1 está subrepresentada, probablemente debido a las restricciones en el acceso al diagnóstico temprano y la tasa de mortalidad alta y temprana.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child , Adolescent , Adult , Young Adult , Spinal Muscular Atrophies of Childhood/diagnosis , Neurodegenerative Diseases/diagnosis , Phenotype , Respiration, Artificial , Scoliosis/surgery , Socioeconomic Factors , Biopsy , Spinal Muscular Atrophies of Childhood/mortality , Spinal Muscular Atrophies of Childhood/therapy , Chile/epidemiology , Residence Characteristics , Prevalence , Cohort Studies , Neurodegenerative Diseases/mortality , Neurodegenerative Diseases/therapy , Genetic Predisposition to Disease , Electromyography , Genotype
17.
Acta Neuropathol Commun ; 7(1): 3, 2019 01 05.
Article in English | MEDLINE | ID: mdl-30611313

ABSTRACT

Several morphological phenotypes have been associated to RYR1-recessive myopathies. We recharacterized the RYR1-recessive morphological spectrum by a large monocentric study performed on 54 muscle biopsies from a large cohort of 48 genetically confirmed patients, using histoenzymology, immunohistochemistry, and ultrastructural studies. We also analysed the level of RyR1 expression in patients' muscle biopsies. We defined "dusty cores" the irregular areas of myofibrillar disorganisation characterised by a reddish-purple granular material deposition with uneven oxidative stain and devoid of ATPase activity, which represent the characteristic lesion in muscle biopsy in 54% of patients. We named Dusty Core Disease (DuCD) the corresponding entity of congenital myopathy. Dusty cores had peculiar histological and ultrastructural characteristics compared to the other core diseases. DuCD muscle biopsies also showed nuclear centralization and type1 fibre predominance. Dusty cores were not observed in other core myopathies and centronuclear myopathies. The other morphological groups in our cohort of patients were: Central Core (CCD: 21%), Core-Rod (C&R:15%) and Type1 predominance "plus" (T1P+:10%). DuCD group was associated to an earlier disease onset, a more severe clinical phenotype and a lowest level of RyR1 expression in muscle, compared to the other groups. Variants located in the bridge solenoid and the pore domains were more frequent in DuCD patients. In conclusion, DuCD is the most frequent histopathological presentation of RYR1-recessive myopathies. Dusty cores represent the unifying morphological lesion among the DuCD pathology spectrum and are the morphological hallmark for the recessive form of disease.


Subject(s)
Muscular Diseases/genetics , Muscular Diseases/pathology , Ryanodine Receptor Calcium Release Channel/genetics , Adolescent , Adult , Aged , Biopsy , Child , Child, Preschool , Cohort Studies , Female , Genes, Recessive , Humans , Infant , Infant, Newborn , Male , Middle Aged , Muscle, Skeletal/ultrastructure , Muscular Diseases/metabolism , Ryanodine Receptor Calcium Release Channel/metabolism , Young Adult
18.
J Neurol Neurosurg Psychiatry ; 90(5): 576-585, 2019 05.
Article in English | MEDLINE | ID: mdl-30530568

ABSTRACT

BACKGROUND AND OBJECTIVE: Oculopharyngeal muscular dystrophy (OPMD) is a genetic disorder caused by an abnormal expansion of GCN triplets within the PABPN1 gene. Previous descriptions have focused on lower limb muscles in small cohorts of patients with OPMD, but larger imaging studies have not been performed. Previous imaging studies have been too small to be able to correlate imaging findings to genetic and clinical data. METHODS: We present cross-sectional, T1-weighted muscle MRI and CT-scan data from 168 patients with genetically confirmed OPMD. We have analysed the pattern of muscle involvement in the disease using hierarchical analysis and presented it as heatmaps. Results of the scans were correlated with genetic and clinical data. RESULTS: Fatty replacement was identified in 96.7% of all symptomatic patients. The tongue, the adductor magnus and the soleus were the most commonly affected muscles. Muscle pathology on MRI correlated positively with disease duration and functional impairment. CONCLUSIONS: We have described a pattern that can be considered characteristic of OPMD. An early combination of fat replacement in the tongue, adductor magnus and soleus can be helpful for differential diagnosis. The findings suggest the natural history of the disease from a radiological point of view. The information generated by this study is of high diagnostic value and important for clinical trial development.


Subject(s)
Muscle, Skeletal/diagnostic imaging , Muscular Dystrophy, Oculopharyngeal/diagnostic imaging , Adult , Cohort Studies , Cross-Sectional Studies , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Muscle, Skeletal/pathology , Muscular Dystrophy, Oculopharyngeal/complications , Muscular Dystrophy, Oculopharyngeal/pathology , Tomography, X-Ray Computed
19.
Muscle Nerve ; 59(4): 436-444, 2019 04.
Article in English | MEDLINE | ID: mdl-30578674

ABSTRACT

INTRODUCTION: The manner in which imaging patterns change over the disease course and with increasing disability in dysferlinopathy is not fully understood. METHODS: Fibroadipose infiltration of 61 muscles was scored based on whole-body MRI of 33 patients with dysferlinopathy and represented in a heatmap. We trained random forests to predict disease duration, Motor Function Measure dimension 1 (MFM-D1), and modified Rankin scale (MRS) score based on muscle scoring and selected the most important muscle for predictions. RESULTS: The heatmap delineated positive and negative fingerprints in dysferlinopathy. Disease duration was related to infiltration of infraspinatus, teres major-minor, and supraspinatus muscles. MFM-D1 decreased with higher infiltration of teres major-minor, triceps, and sartorius. MRS related to infiltration of vastus medialis, gracilis, infraspinatus, and sartorius. DISCUSSION: Dysferlinopathy shows a recognizable muscle MRI pattern. Fibroadipose infiltration in specific muscles of the thigh and the upper limb appears to be an important marker for disease progression. Muscle Nerve 59:436-444, 2019.


Subject(s)
Disability Evaluation , Muscle, Skeletal/diagnostic imaging , Muscular Dystrophies, Limb-Girdle/diagnostic imaging , Adipose Tissue/pathology , Adult , Female , Fibrosis/diagnostic imaging , Fibrosis/pathology , Humans , Machine Learning , Magnetic Resonance Imaging , Male , Middle Aged , Predictive Value of Tests , Rotator Cuff/diagnostic imaging , Young Adult
20.
J Neurol Sci ; 395: 84-87, 2018 12 15.
Article in English | MEDLINE | ID: mdl-30300819

ABSTRACT

This paper illustrates the cases of two patients with an acute onset of right brachial neuropathic pain, flaccid paralysis and contralateral thermal and thermal pain hypoesthesia, without posterior column impairment nor pyramidal signs below the segmental lesion. MRI showed right sided spinal cord infarction, in the anterior spinal artery territory between C1 and C5 in one patient and between C3 and C7 in the other. Contact Heat Evoked Potentials and Quantitative Thermal Sensory testing are consistent with contralateral, but not ipsilateral, spinothalamic tract involvement. Electromyographic results established ipsilateral segmental denervation and somatosensory evoked responses were consistent with dorsal column sparing. Unilateral anterior cervical spinal cord infarction may present with acute ipsilateral segmental neuropathic pain, lower motor neurone-type weakness, contralateral thermoanalgesia and no pyramidal signs. The ipsilateral pain provides novel evidence that in some instances, ventral roots can play a role in nociception in humans. The infarcted territory may result from occlusion of a sulcal commissural artery or a number of more proximal vessels (including a single or duplicated anterior spinal artery, vertebral arteries or feeding radicular arteries).


Subject(s)
Infarction/complications , Infarction/physiopathology , Neuralgia/complications , Neuralgia/physiopathology , Spinal Cord Ischemia/complications , Spinal Cord Ischemia/physiopathology , Afferent Pathways/diagnostic imaging , Afferent Pathways/physiopathology , Cervical Cord/blood supply , Cervical Cord/diagnostic imaging , Cervical Cord/physiopathology , Female , Humans , Infarction/diagnostic imaging , Infarction/drug therapy , Neuralgia/diagnostic imaging , Neuralgia/drug therapy , Sensory Receptor Cells/physiology , Spinal Cord Ischemia/diagnostic imaging , Spinal Cord Ischemia/drug therapy , Spinal Nerve Roots/diagnostic imaging , Spinal Nerve Roots/physiopathology , Treatment Failure , Young Adult
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