RESUMEN

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a treatable chronic disorder of the peripheral nervous system. We retrospectively studied 30 children with a suspected diagnosis of CIDP. The diagnosis of CIDP was compared against the childhood CIDP revised diagnostic criteria 2000. Of the 30 children, five did not meet the criteria and four others met the criteria but subsequently had alternative diagnosis, leaving a total of 21 children (12 male) with CIDP as the final diagnosis. Thirteen children presented with chronic symptom-onset (>8 weeks). The majority presented with gait difficulties or pain in legs (n = 16). 12 children (57%) met the neurophysiological criteria and 18/19 (94%) met the cerebrospinal fluid criteria. Nerve biopsy was suggestive in 3/9 (33%), with magnetic resonance imaging supportive in 9/20 (45%). Twenty-one children received immuno-modulatory treatment at first presentation, of which majority (n = 19, 90%) received IVIG (immunoglobulin) monotherapy with 13 (68%) showing a good response. 8 children received second line treatment with either IVIG or steroids or plasmapharesis (PE) and 4 needed other immune-modulatory agents. During a median follow-up of 3.6 years, 9 (43%) had a monophasic course and 12 (57%) had a relapsing-remitting course. At last paediatric follow up 7 (33%) were off all treatment, 9 (43%) left with no or minimal residual disability and 6 (28%) children were walking with assistance (n = 3) or were non-ambulant (n = 3). Our review highlights challenges in the diagnosis and management of paediatric CIDP. It also confirms that certain metabolic disorders may mimic CIDP.

Asunto(s)

Marcha/fisiología , Inmunoglobulinas Intravenosas/uso terapéutico , Factores Inmunológicos/uso terapéutico , Plasmaféresis , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/diagnóstico , Adolescente , Niño , Preescolar , Progresión de la Enfermedad , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Conducción Nerviosa/fisiología , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/fisiopatología , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/terapia , Estudios Retrospectivos , Resultado del Tratamiento

RESUMEN

BACKGROUND/PURPOSE: Duchenne Mmuscular Ddystrophy (DMD) related cardiomyopathy is associated with significant perioperative mortality. Cardiac MRI (CMR) has not previously been systematically evaluated as pre-operative assessment tool for heart function in DMD. Our aim was to establish whether CMR versus echocardiography contributes to pre-operative DMD assessment. METHODS: Case records were retrospectively reviewed of 35 consecutive DMD boys who underwent evaluation for surgical procedures between 2010 and 2013. RESULTS: Echocardiography revealed a median left ventricular (LV) shortening fraction (SF) of 29/% (range: 7-44). 37% of boys (13/35) had abnormal SF <25%, 66% (23/35) showed hypokinesia and 26% (9/35) had LV dilatation. CMR revealed a median left ventricular ejection fraction (LVEF) of 52% (range: 27-67%). 57% of boys (20/35) had abnormal LVEF <55%, 71% (25/35) had hypokinesia, and 82% late gadolinium enhancement. Extensive versus minimal late gadolinium enhancement was associated with reduced left ventricular ejection fraction (48% vs 58%; p = 0.003) suggesting more severe cardiomyopathy. Although echocardiography shortening fraction correlated with CMR ejection fraction (rs = 0.67; p < 0.001), three-quarter of echocardiography studies had suboptimal scanning windows and in 26% measurements significantly over- or underestimated left-ventricular function compared to CMR. CONCLUSION: Our findings clearly demonstrate the added value of CMR versus echocardiography in assessing DMD-cardiomyopathy. Particularly when echocardiographic scanning windows are suboptimal, CMR should be considered to allow accurate pre-operative cardiac assessment.

Asunto(s)

Cardiomiopatías/cirugía , Ecocardiografía/métodos , Imagen por Resonancia Cinemagnética/métodos , Distrofia Muscular de Duchenne/complicaciones , Cuidados Preoperatorios/métodos , Cardiomiopatías/etiología , Niño , Humanos , Masculino , Distrofia Muscular de Duchenne/fisiopatología , Estudios Retrospectivos

RESUMEN

BACKGROUND AND OBJECTIVES: Nemaline myopathy may be caused by pathogenic variants in the TPM3 gene and is then called NEM1. All previously identified disease-causing variants are point mutations including missense, nonsense and splice-site variants. The aim of the study was to identify the disease-causing gene in this patient and verify the NM diagnosis. METHODS: Mutation analysis methods include our self-designed nemaline myopathy array, The Nemaline Myopathy Comparative Genomic Hybridisation Array (NM-CGH array), whole-genome array-CGH, dHPLC, Sanger sequencing and whole-exome sequencing. The diagnostic muscle biopsy was investigated further by routine histopathological methods. RESULTS: We present here the first large (17-21 kb) aberration in the α-tropomyosinslow gene (TPM3), identified using the NM-CGH array. This homozygous deletion removes the exons 1a and 2b as well as the promoter of the TPM3 isoform encoding Tpm3.12st. The severe phenotype included paucity of movement, proximal and axial weakness and feeding difficulties requiring nasogastric tube feeding. The infant died at the age of 17.5 months. Muscle biopsy showed variation in fibre size and rods in a population of hypotrophic muscle fibres expressing slow myosin, often with internal nuclei, and abnormal immunolabelling revealing many hybrid fibres. CONCLUSIONS: This is the only copy number variation we have identified in any NM gene other than nebulin (NEB), suggesting that large deletions or duplications in these genes are very rare, yet possible, causes of NM.

RESUMEN

Phospholipase A2 associated neurodegeneration (PLAN) is a major phenotype of autosomal recessive Neurodegeneration with Brain Iron Accumulation (NBIA). We describe the clinical phenotypes, neuroimaging features and PLA2G6 mutations in 5 children, of whom 4 presented with infantile neuroaxonal dystrophy (INAD). One other patient was diagnosed with the onset of PLAN in childhood, and our report highlights the diagnostic challenges associated with this atypical PLAN subtype. In this series, the neuroradiological relevance of classical PLAN features as well as apparent claval hypertrophy' is explored. Novel PLA2G6 mutations were identified in all patients. PLAN should be considered not only in patients presenting with a classic INAD phenotype but also in older patients presenting later in childhood with non-specific progressive neurological features including social communication difficulties, gait disturbance, dyspraxia, neuropsychiatric symptoms and extrapyramidal motor features.

Asunto(s)

Fosfolipasas A2 Grupo VI/genética , Distrofias Neuroaxonales/diagnóstico por imagen , Distrofias Neuroaxonales/patología , Edad de Inicio , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Preescolar , Femenino , Variación Genética , Humanos , Lactante , Irlanda , Masculino , Mutación , Distrofias Neuroaxonales/genética , Fenotipo , Radiografía , Reino Unido

RESUMEN

Mutations in the skeletal muscle ryanodine receptor (RYR1) gene are a common cause of neuromuscular disease, ranging from various congenital myopathies to the malignant hyperthermia (MH) susceptibility trait without associated weakness. We sequenced RYR1 in 39 unrelated families with rhabdomyolysis and/or exertional myalgia, frequent presentations in the neuromuscular clinic that often remain unexplained despite extensive investigations. We identified 9 heterozygous RYR1 mutations/variants in 14 families, 5 of them (p.Lys1393Arg; p.Gly2434Arg; p.Thr4288_Ala4290dup; p.Ala4295Val; and p.Arg4737Gln) previously associated with MH. Index cases presented from 3 to 45 years with rhabdomyolysis, with or without exertional myalgia (n=12), or isolated exertional myalgia (n=2). Rhabdomyolysis was commonly triggered by exercise and heat and, less frequently, viral infections, alcohol and drugs. Most cases were normally strong and had no personal MH history. Inconsistent additional features included heat intolerance, and cold-induced muscle stiffness. Muscle biopsies showed mainly subtle changes. Familial RYR1 mutations were confirmed in relatives with similar or no symptoms. These findings suggest that RYR1 mutations may account for a substantial proportion of patients presenting with unexplained rhabdomyolysis and/or exertional myalgia. Associated clinico-pathological features may be subtle and require a high degree of suspicion. Additional family studies are paramount in order to identify potentially MH susceptible relatives.

Asunto(s)

Hipertermia Maligna/genética , Mutación/genética , Rabdomiólisis/genética , Canal Liberador de Calcio Receptor de Rianodina/genética , Ejercicio Físico/fisiología , Femenino , Heterocigoto , Humanos , Masculino , Hipertermia Maligna/complicaciones , Fenotipo , Rabdomiólisis/complicaciones , Canal Liberador de Calcio Receptor de Rianodina/metabolismo

RESUMEN

The congenital myopathies are a group of inherited neuromuscular disorders mainly defined on the basis of characteristic histopathological features. We analysed 66 patients assessed at a single centre over a 5 year period. Of the 54 patients where muscle biopsy was available, 29 (54%) had a core myopathy (central core disease, multi-minicore disease), 9 (17%) had nemaline myopathy, 7 (13%) had myotubular/centronuclear myopathy, 2 (4%) had congenital fibre type disproportion, 6 (11%) had isolated type 1 predominance and 1 (2%) had a mixed core-rod myopathy. Of the 44 patients with a genetic diagnosis, RYR1 was mutated in 26 (59%), ACTA1 in 7 (16%), SEPN1 in 7 (16%), MTM1 in 2 (5%), NEB in 1 (2%) and TPM3 in 1 (2%). Clinically, 77% of patients older than 18 months could walk independently. 35% of all patients required ventilatory support and/or enteral feeding. Clinical course was stable or improved in 57/66 (86%) patients, whilst 4 (6%) got worse and 5 (8%) died. These findings indicate that core myopathies are the most common form of congenital myopathies and that more than half can be attributed to RYR1 mutations. The underlying genetic defect remains to be identified in 1/3 of congenital myopathies cases.

Asunto(s)

Músculo Esquelético/patología , Enfermedades Musculares/congénito , Enfermedades Musculares/diagnóstico , Adolescente , Edad de Inicio , Niño , Preescolar , Progresión de la Enfermedad , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Enfermedades Musculares/genética , Enfermedades Musculares/patología , Mutación , Reino Unido

RESUMEN

The Dubowitz Neuromuscular Centre is the UK National Commissioning Group referral centre for congenital muscular dystrophy (CMD). This retrospective review reports the diagnostic outcome of 214 UK patients referred to the centre for assessment of 'possible CMD' between 2001 and 2008 with a view to commenting on the variety of disorders seen and the relative frequency of CMD subtypes in this patient population. A genetic diagnosis was reached in 53 of 116 patients fulfilling a strict criteria for the diagnosis of CMD. Within this group the most common diagnoses were collagen VI related disorders (19%), dystroglycanopathy (12%) and merosin deficient congenital muscular dystrophy (10%). Among the patients referred as 'possible CMD' that did not meet our inclusion criteria, congenital myopathies and congenital myasthenic syndromes were the most common diagnoses. In this large study on CMD the diagnostic outcomes compared favourably with other CMD population studies, indicating the importance of an integrated clinical and pathological assessment of this group of patients.

Asunto(s)

Distrofias Musculares/congénito , Distrofias Musculares/diagnóstico , Adolescente , Adulto , Niño , Preescolar , Servicios de Diagnóstico , Femenino , Pruebas Genéticas , Humanos , Lactante , Masculino , Distrofias Musculares/genética , Estudios Retrospectivos , Reino Unido

RESUMEN

OBJECTIVE: To assess the clinical course and genotype-phenotype correlations in patients with selenoprotein-related myopathy (SEPN1-RM) due to selenoprotein N1 gene (SEPN1) mutations for a retrospective cross-sectional study. METHODS: Forty-one patients aged 1-60 years were included. Clinical data including scoliosis, respiratory function, and growth measurements were collected by case note review. RESULTS: Mean age at onset was 2.7 years, ranging from birth to the second decade of life. All but 2 remained independently ambulant: one lost ambulation at age 5 years and another in his late 50s. The mean age of starting nocturnal noninvasive ventilation (NIV) was 13.9 years. One child required full-time NIV at the age of 1 year while in 2 cases NIV was started at 33 years. Two patients died from respiratory failure at the age of 10 and 22 years, respectively. The mean age at scoliosis onset was 10 years, in most cases preceded by rigidity of the spine. Fourteen patients had successful spinal surgery (mean age 13.9 years). Twenty-one were underweight; however, overt feeding difficulties were not a feature. CONCLUSIONS: This study describes the largest population affected by SEPN1-RM reported so far. Our findings show that the spectrum of severity is wider than previously reported. Respiratory insufficiency generally develops by 14 years but may occur as early as in infancy or not until the fourth decade. Motor abilities remain essentially static over time even in patients with early presentation. Most adult patients remain ambulant and fully employed.

Asunto(s)

Estudios de Asociación Genética , Proteínas Musculares/genética , Enfermedades Musculares/genética , Enfermedades Musculares/fisiopatología , Selenoproteínas/genética , Índice de Severidad de la Enfermedad , Adolescente , Adulto , Niño , Preescolar , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Enfermedades Musculares/patología , Mutación , Adulto Joven

RESUMEN

OBJECTIVE: There are currently no effective treatments to halt the muscle breakdown in Duchenne muscular dystrophy (DMD), although genetic-based clinical trials are being piloted. Most of these trials have as an endpoint the restoration of dystrophin in muscle fibers, hence requiring sufficiently well-preserved muscle of recruited patients. The choice of the muscles to be studied and the role of noninvasive methods to assess muscle preservation therefore require further evaluation. METHODS: We studied the degree of muscle involvement in the lower leg muscles of 34 patients with DMD >8 years, using muscle MRI. In a subgroup of 15 patients we correlated the muscle MRI findings with the histology of open extensor digitorum brevis (EDB) muscle biopsies. Muscle MRI involvement was assigned using a scale 0-4 (normal-severe). RESULTS: In all patients we documented a gradient of involvement of the lower leg muscles: the posterior compartment (gastrocnemius > soleus) was most severely affected; the anterior compartment (tibialis anterior/posterior, popliteus, extensor digitorum longus) least affected. Muscle MRI showed EDB involvement that correlated with the patient's age (p = 0.055). We show a correlation between the MRI and EDB histopathologic changes, with MRI 3-4 grades associated with a more severe fibro-adipose tissue replacement. The EDB was sufficiently preserved for bulk and signal intensity in 18/22 wheelchair users aged 10-16.6 years. CONCLUSION: This study provides a detailed correlation between muscle histology and MRI changes in DMD and demonstrates the value of this imaging technique as a reliable tool for the selection of muscles in patients recruited into clinical trials.

Asunto(s)

Músculo Esquelético/patología , Distrofia Muscular de Duchenne/patología , Adolescente , Niño , Pie , Humanos , Pierna , Imagen por Resonancia Magnética , Masculino , Músculo Esquelético/fisiopatología , Distrofia Muscular de Duchenne/fisiopatología

RESUMEN

OBJECTIVE: Centronuclear myopathy (CNM) is a rare congenital myopathy characterized by prominence of central nuclei on muscle biopsy. CNM has been associated with mutations in MTM1, DNM2, and BIN1 but many cases remain genetically unresolved. RYR1 encodes the principal sarcoplasmic reticulum calcium release channel and has been implicated in various congenital myopathies. We investigated whether RYR1 mutations cause CNM. METHODS: We sequenced the entire RYR1 coding sequence in 24 patients with a diagnosis of CNM from South Africa (n = 14) and Europe (n = 10) and identified mutations in 17 patients. The most common genotypes featured compound heterozygosity for RYR1 missense mutations and mutations resulting in reduced protein expression, including intronic splice site and frameshift mutations. RESULTS: The high incidence in South African patients (n = 12/14) in conjunction with recurrent RYR1 mutations associated with common haplotypes suggested the presence of founder effects. In addition to central nuclei, prominent histopathological findings included (often multiple) internalized nuclei and type 1 fiber predominance and hypotrophy with relative type 2 hypertrophy. Although cores were not typically seen on oxidative stains, electron microscopy revealed subtle abnormalities in most cases. External ophthalmoplegia, proximal weakness, and bulbar involvement were prominent clinical findings. INTERPRETATION: Our findings expand the range of RYR1-related phenotypes and suggest RYR1 mutations as a common cause of congenital myopathies with central nuclei. Corresponding to recent observations in X-linked CNM, these findings indicate disturbed assembly and/or malfunction of the excitation-contraction machinery as a key mechanism in CNM and related myopathies.

Asunto(s)

Músculo Esquelético/patología , Miopatías Estructurales Congénitas/etiología , Canal Liberador de Calcio Receptor de Rianodina/genética , Adolescente , Niño , Preescolar , Europa (Continente) , Genotipo , Heterocigoto , Humanos , Masculino , Mutación , Miopatías Estructurales Congénitas/diagnóstico , Miopatías Estructurales Congénitas/genética , Miopatías Estructurales Congénitas/patología , Fenotipo , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Sudáfrica

RESUMEN

Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD) and limb girdle muscular dystrophies (LGMD) represent a significant proportion of paediatric and adult neuromuscular neurology practice. The proactive symptom-based multidisciplinary team (MDT) management and access to non-invasive ventilation have enabled improved survival into adulthood. Nevertheless the severe disability imposed by conditions such as DMD poses a challenge for successful transition of care and management for paediatric and adult neurology teams. DMD is discussed in detail as a paradigm illustrating diagnosis, management and role for different pharmacological interventions to improve survival, but also challenges in adulthood care, and cutting-edge therapies. LGMDs are much rarer than DMD and BMD, and in addition there is a significant genetic and clinical heterogeneity, which leads to diagnostic difficulties. The clinical and laboratory diagnostic features of seven LGMD subtypes are summarised, and their allelic "non-limb girdle" phenotypes are tabulated to illustrate the theme of one gene causing multiple clinical phenotypes, with the aim of refining the clinician's diagnostic approach. The lessons learnt from DMD MDT management to improve survival are broadly applicable to LGMDs with severe motor disability/multisystem complications.

RESUMEN

OBJECTIVE: To describe the course, complications, and prognosis of Ullrich congenital muscular dystrophy (UCMD), with special reference to life-changing events, including loss of ambulation, respiratory insufficiency, and death. METHODS: Review of the case notes of 13 patients with UCMD, aged 15 years or older at last visit, followed up at a tertiary neuromuscular centre, London, UK, from 1977 to 2007. Data collected were age at onset of symptoms, presenting symptoms, mobility, contractures, scoliosis, skin abnormalities, respiratory function, and feeding difficulties. RESULTS: The mean age at onset of symptoms was 12 months (SD 14 months). Eight patients (61.5%) acquired independent ambulation at a mean age of 1.7 years (SD 0.8 years). Nine patients (69.2%) became constant wheelchair users at a mean age of 11.1 years (SD 4.8 years). Three patients continued to ambulate indoors with assistance. Forced vital capacity (FVC) values were abnormal in all patients from age 6 years. The mean FVC (% predicted) declined at a mean rate of 2.6% (SD 4.1%) yearly. Nine patients (69.2%) started noninvasive ventilation at a mean age of 14.3 years (SD 5.0 years). Two patients died of respiratory insufficiency. CONCLUSION: In Ullrich congenital muscular dystrophy (UCMD), the decline in motor and respiratory functions is more rapid in the first decade of life. The deterioration is invariable, but not always correlated with age or severity at presentation. This information should be of help to better anticipate the difficulties encountered by patients with UCMD and in planning future therapeutic trials in this condition.

Asunto(s)

Debilidad Muscular/diagnóstico , Distrofias Musculares/diagnóstico , Parálisis Respiratoria/diagnóstico , Adolescente , Adulto , Distribución por Edad , Edad de Inicio , Niño , Estudios de Cohortes , Colágeno Tipo VI/genética , Comorbilidad , Contractura/etiología , Contractura/fisiopatología , Evaluación de la Discapacidad , Progresión de la Enfermedad , Humanos , Estudios Longitudinales , Limitación de la Movilidad , Mortalidad , Debilidad Muscular/mortalidad , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Músculo Esquelético/fisiopatología , Distrofias Musculares/congénito , Distrofias Musculares/mortalidad , Mutación/genética , Parálisis Respiratoria/mortalidad , Índice de Severidad de la Enfermedad , Capacidad Vital/genética , Adulto Joven

RESUMEN

Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD) and limb girdle muscular dystrophies (LGMD) represent a significant proportion of paediatric and adult neuromuscular neurology practice. The proactive symptom-based multidisciplinary team (MDT) management and access to non-invasive ventilation have enabled improved survival into adulthood. Nevertheless the severe disability imposed by conditions such as DMD poses a challenge for successful transition of care and management for paediatric and adult neurology teams. DMD is discussed in detail as a paradigm illustrating diagnosis, management and role for different pharmacological interventions to improve survival, but also challenges in adulthood care, and cutting-edge therapies. LGMDs are much rarer than DMD and BMD, and in addition there is a significant genetic and clinical heterogeneity, which leads to diagnostic difficulties. The clinical and laboratory diagnostic features of seven LGMD subtypes are summarised, and their allelic "non-limb girdle" phenotypes are tabulated to illustrate the theme of one gene causing multiple clinical phenotypes, with the aim of refining the clinician's diagnostic approach. The lessons learnt from DMD MDT management to improve survival are broadly applicable to LGMDs with severe motor disability/multisystem complications.

Asunto(s)

Corticoesteroides/uso terapéutico , Distrofias Musculares/diagnóstico , Distrofias Musculares/terapia , Modalidades de Fisioterapia , Síndromes de la Apnea del Sueño/terapia , Adulto , Niño , Humanos , Distrofias Musculares/complicaciones , Distrofias Musculares/genética , Distrofias Musculares/fisiopatología , Distrofia Muscular de Cinturas/diagnóstico , Distrofia Muscular de Cinturas/terapia , Distrofia Muscular de Duchenne/diagnóstico , Distrofia Muscular de Duchenne/terapia , Síndromes de la Apnea del Sueño/etiología , Resultado del Tratamiento

RESUMEN

Spinal muscular atrophy with respiratory distress (SMARD1: mu-binding protein 2 gene mutation) is characterised by low birth weight, progressive distal limb weakness, diaphragmatic paralysis and subsequent respiratory failure manifesting before 13 months of age. Our case report illustrates marked phenotype variability in two siblings with an identical genetic mutation of SMARD1, one of whom died of fulminant respiratory failure aged 6 months, whereas the other shows limb weakness but, only mild sleep hypoventilation aged 12 years. This suggests other compensatory mechanisms may play a role in modifying SMARD1; broadening our perception of phenotype. Therefore, SMARD1 phenotype should be considered in cases of atypical spinal muscular atrophy even in the absence of overt diaphragmatic weakness.

Asunto(s)

Proteínas de Unión al ADN/genética , Predisposición Genética a la Enfermedad/genética , Atrofia Muscular Espinal/genética , Mutación/genética , Insuficiencia Respiratoria/genética , Factores de Transcripción/genética , Adolescente , Análisis Mutacional de ADN , Progresión de la Enfermedad , Resultado Fatal , Femenino , Marcadores Genéticos/genética , Genotipo , Humanos , Lactante , Debilidad Muscular/genética , Fenotipo , Parálisis Respiratoria/genética , Hermanos

RESUMEN

Duchenne muscular dystrophy (DMD) is familiar to paediatricians as the most common childhood muscular dystrophy and leads to severe disability and early death in the late teenage years if untreated. Improvements in general care, glucocorticoid corticosteroid treatment, non-invasive ventilatory support, and cardiomyopathy and scoliosis management have significantly changed the course of DMD in treated individuals, so that survival into adulthood is now a realistic possibility for most patients. This has important implications for the medical and social sectors involved in the transition to adult medical services and the provision of suitable employment and social care. Multidisciplinary team working for optimal management of DMD-specific multisystem complications is essential, and collaboration in disease specific national clinical networks is recommended. Several curative therapeutic strategies including cell and gene therapy are being pursued but are still at an experimental stage.

Asunto(s)

Distrofia Muscular de Duchenne/terapia , Cardiomiopatía Dilatada/etiología , Cardiomiopatía Dilatada/terapia , Distrofina/genética , Terapia Genética/métodos , Glucocorticoides/uso terapéutico , Humanos , Masculino , Distrofia Muscular de Duchenne/complicaciones , Distrofia Muscular de Duchenne/diagnóstico , Distrofia Muscular de Duchenne/genética , Grupo de Atención al Paciente , Modalidades de Fisioterapia , Trastornos Respiratorios/etiología , Trastornos Respiratorios/terapia , Escoliosis/etiología , Escoliosis/terapia

RESUMEN

The Congenital Myasthenic Syndromes (CMS), a group of heterogeneous genetic disorders of neuromuscular transmission, are often misdiagnosed as congenital muscular dystrophy (CMD) or myopathies and present particular management problems. We present our experience of 46 children with CMS, referred to us between 1992-2007 with provisional diagnoses of congenital myopathy (22/46), CMS or limb-girdle myasthenia (9/46), central hypotonia or neurometabolic disease (5/46), myasthenia gravis (4/46), limb-girdle or congenital muscular dystrophy (4/46) and SMA (2/46). Diagnosis was often considerably delayed (up to 18y4 m), despite the early symptoms in most cases. Diagnostic clues in the neonates were feeding difficulties (29/46), hypotonia with or without limb weakness (21/46), ptosis (19/46), respiratory insufficiency (12/46), contractures (4/46) and stridor (6/46). Twenty-five children had delayed motor milestones. Fatigability developed in 43 and a variable degree of ptosis was eventually present in 40. Over the period of the study, the mainstay of EMG diagnosis evolved from repetitive nerve stimulation to stimulation single fibre EMG. The patients were studied by several different operators. 66 EMGs were performed in 40 children, 29 showed a neuromuscular junction abnormality, 7 were myopathic, 2 had possible neurogenic changes and 28 were normal or inconclusive. A repetitive CMAP was detected in only one of seven children with a COLQ mutation and neither of the two children with Slow Channel Syndrome mutations. Mutations have been identified so far in 32/46 children: 10 RAPSN, 7 COLQ, 6 CHRNE, 7 DOK7, 1 CHRNA1 and 1 CHAT. 24 of 25 muscle biopsies showed myopathic changes with fibre size variation; 14 had type-1 fibre predominance. Three cases showed small type-1 fibres resembling fibre type disproportion, and four showed core-like lesions. No specific myopathic features were associated with any of the genes. Twenty children responded to Pyridostigmine treatment alone, 11 to Pyridostigmine with either 3, 4 DAP or Ephedrine and five to Ephedrine alone. Twenty one children required acute or chronic respiratory support, with tracheostomy in 4 and nocturnal or emergency non-invasive ventilation in 9. Eight children had gastrostomy. Another 11 were underweight for height indicative of failure to thrive and required dietetic input. A high index of clinical suspicion, repeat EMG by an experienced electromyographer and, if necessary, a therapeutic trial of Pyridostigmine facilitates the diagnosis of CMS with subsequent molecular genetic confirmation. This guides rational therapy and multidisciplinary management, which may be crucial for survival, particularly in pedigrees where previous deaths have occurred in infancy.

Asunto(s)

Síndromes Miasténicos Congénitos/diagnóstico , Síndromes Miasténicos Congénitos/terapia , Adolescente , Edad de Inicio , Biopsia/métodos , Niño , Preescolar , Análisis Mutacional de ADN , Electromiografía , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Músculo Esquelético/patología , Mutación , Síndromes Miasténicos Congénitos/clasificación , Síndromes Miasténicos Congénitos/fisiopatología , Respiración , Estudios Retrospectivos

RESUMEN

BACKGROUND: Duchenne muscular dystrophy (DMD) is the most common muscular dystrophy of childhood. This incurable disease is characterised by muscle wasting and loss of walking ability leading to complete wheelchair dependence by 13 years of age. Prolongation of walking is one of the major aims of treatment. OBJECTIVES: The aim of this review was to assess whether glucocorticoid corticosteroids stabilize or improve muscle strength and walking in boys with DMD. SEARCH STRATEGY: This is an update of the Cochrane systematic review first published in 2004 (Manzur 2004). We searched the Cochrane Neuromuscular Disease Group Trials Register (August 2006) using the term 'Duchenne muscular dystrophy'. We also searched MEDLINE (January 1966 to July 2007), EMBASE (January 1980 to August 2006), CINAHL and LILACS (January 1982 to August 2006). We wrote to authors of published studies and other experts in this disease to help identify other trials, checked the references in the identified trials and hand searched the abstracts of relevant journals. SELECTION CRITERIA: Types of studies: randomised or quasi-randomised trials. TYPES OF PARTICIPANTS: all patients with a definite diagnosis of Duchenne muscular dystrophy. Types of interventions: glucocorticoids such as prednisone, prednisolone, deflazacort or others, with a minimum treatment period of three months. PRIMARY OUTCOME MEASURE: prolongation of walking (independent walking without long leg calipers). SECONDARY OUTCOME MEASURES: strength outcome measures, manual muscle strength testing using Medical Research Council strength scores, functional outcome measures and adverse events. DATA COLLECTION AND ANALYSIS: We identified six randomised controlled trials that met the inclusion criteria for our review, and one of these (Beenakker 2005) is a new addition to this update, as it was published subsequent to our first review (Manzur 2004). Two review authors independently selected the trials for the review and assessed methodological quality. Data extraction and inputting were double-checked. PRIMARY OUTCOME MEASURE: data from one small study used prolongation of walking as an outcome measure and did not show significant benefit. SECONDARY OUTCOME MEASURES: The meta-analysis of the results from four randomised controlled trials with altogether 249 participants showed that glucocorticoid corticosteroids improved muscle strength and function over six months. Improvements were seen in time taken to rise from the floor (Gowers' time), nine metres walking time, four-stair climbing time, ability to lift weights, leg function grade and forced vital capacity. One randomised controlled trial with altogether 28 participants showed that glucocorticoid corticosteroids stabilize muscle strength and function for up to two years. The most effective prednisolone regime appears to be 0.75 mg/kg/day, given in a daily dose regime. Not enough data were available to compare efficacy of prednisone with deflazacort. Adverse effects: Excessive weight gain, behavioural abnormalities, cushingoid appearance and excessive hair growth were all more common with glucocorticoid corticosteroids than placebo. Long-term adverse effects of glucocorticoid therapy could not be evaluated because of the short-term duration of the randomised studies.Non-randomised studies: A number of non-randomised studies with important efficacy and adverse effects data are tabulated and discussed. AUTHORS' CONCLUSIONS: There is evidence from randomised controlled studies that glucocorticoid corticosteroid therapy in Duchenne muscular dystrophy improves muscle strength and function in the short-term (six months to two years). The most effective prednisolone regime appears to be 0.75 mg/kg/day, given daily. In the short term, adverse effects were significantly more common but not clinically severe. Long-term benefits and hazards of glucocorticoid treatment cannot be evaluated from the currently published randomised studies. Non-randomised studies support the conclusions of functional benefits but also identify clinically significant adverse effects of long-term treatment. These benefits and adverse effects have implications for future research studies and clinical practice.

Asunto(s)

Corticoesteroides/uso terapéutico , Glucocorticoides/uso terapéutico , Distrofia Muscular de Duchenne/tratamiento farmacológico , Corticoesteroides/efectos adversos , Glucocorticoides/efectos adversos , Humanos , Masculino , Prednisolona/uso terapéutico , Prednisona/uso terapéutico , Pregnenodionas/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Caminata

RESUMEN

BACKGROUND AND PURPOSE: Brain imaging is an integral part of the diagnostic work-up for metabolic disorders, and the bedside availability of cranial ultrasonography (cUS) allows very early brain imaging in symptomatic neonates. Our aim was to investigate the role and range of abnormalities seen on cUS in neonates presenting with metabolic disorders. A secondary aim, when possible, was to address the question of whether brain MR imaging is more informative by comparing cUS to MR imaging findings. MATERIALS AND METHODS: Neonates with a metabolic disorder who had at least 1 cUS scan were eligible. cUS images were reviewed for anatomic and maturation features, cysts, calcium, and other abnormalities. When an MR imaging scan had been obtained, both sets of images were compared. RESULTS: Fifty-five infants (35 also had MR imaging) were studied. The most frequent findings were in oxidative phosphorylation disorders (21 cUS and 12 MR imaging): ventricular dilation (11 cUS and 6 MR imaging), germinolytic cysts (GLCs; 7 cUS and 5 MR imaging), and abnormal white matter (7 cUS and 6 MR imaging); in peroxisomal biogenesis disorders (13 cUS and 9 MR imaging): GLCs (10 cUS and 6 MR imaging), ventricular dilation (10 cUS and 5 MR imaging), abnormal cortical folding (8 cUS and 7 MR imaging), and lenticulostriate vasculopathy (8 cUS); in amino acid metabolism and urea cycle disorders (14 cUS and 11 MR imaging): abnormal cortical folding (9 cUS and 4 MR imaging), abnormal white matter (8 cUS and 8 MR imaging), and hypoplasia of the corpus callosum (7 cUS and 6 MR imaging); in organic acid disorders (4 cUS and 2 MR imaging): periventricular white matter echogenicity (2 cUS and 1 MR imaging); and in other disorders (3 cUS and 1 MR imaging): ventricular dilation (2 cUS and 1 MR imaging). cUS findings were consistent with MR imaging findings. cUS was better for visualizing GLCs and calcification. MR imaging was more sensitive for subtle tissue signal intensity changes in the white matter and abnormality in areas difficult to visualize with cUS, though abnormalities of cortical folding suggestive of polymicrogyria were seen on cUS. CONCLUSION: A wide range of abnormalities is seen using cUS in neonatal metabolic disorders. cUS is a reliable bedside tool for early detection of cysts, calcium, structural brain abnormalities, and white matter echogenicity, all suggestive of metabolic disorders.

Asunto(s)

Encefalopatías/diagnóstico , Encéfalo/patología , Ecoencefalografía/métodos , Imagen por Resonancia Magnética/métodos , Enfermedades Metabólicas/diagnóstico , Encefalopatías/complicaciones , Femenino , Humanos , Recién Nacido , Masculino , Enfermedades Metabólicas/complicaciones , Tamizaje Neonatal/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad

Asunto(s)

Dolor de Espalda/etiología , Distrofia Muscular de Duchenne/fisiopatología , Niño , Humanos , Masculino , Distrofia Muscular de Duchenne/patología , Radiografía , Escoliosis/diagnóstico por imagen

RESUMEN

Severe diaphragmatic weakness in infancy is rare. Common causes include structural myopathies, neuromuscular transmission defects, or anterior horn cell dysfunction (spinal muscular atrophy with respiratory distress, SMARD1). We describe a form of infantile diaphragmatic weakness without mutations in the SMARD1 gene, in which pathological and clinical features differ from known conditions, and investigations suggest a myopathy. We identified seven cases in four families. All presented soon after birth with feeding and breathing difficulties, marked head lag, facial weakness, and preserved antigravity movements in the limbs, with arms weaker than legs. All had paradoxical breathing and paralysis of at least one hemi-diaphragm. All required gastrostomy feeding, and all became ventilator-dependent. Investigations included myopathic EMG, muscle biopsy showing myopathic changes, normal electrophysiology and no mutations in SMN1 or IGHMBP2. These seven infants are affected by a myopathic condition clinically resembling SMARD1. However, its pathogenesis appears to be a myopathy affecting predominantly the diaphragm.

Asunto(s)

Proteínas de Unión al ADN/genética , Diafragma/fisiopatología , Debilidad Muscular/congénito , Debilidad Muscular/genética , Enfermedades Musculares/congénito , Enfermedades Musculares/genética , Factores de Transcripción/genética , Creatina Quinasa/metabolismo , Electromiografía , Nutrición Enteral , Extremidades/fisiopatología , Músculos Faciales/fisiopatología , Femenino , Crecimiento/fisiología , Humanos , Lactante , Recién Nacido , Movimiento/fisiología , Debilidad Muscular/fisiopatología , Enfermedades Musculares/fisiopatología , Respiración Artificial , Mecánica Respiratoria/fisiología