Neuromuscular complications of severe COVID-19 in paediatric patients: Medium-term follow-up.

Neuromuscular complications in paediatric patients with severe coronavirus disease 2019 (COVID-19) are poorly characterised. However, adult patients with severe COVID-19 reportedly present with frequent neuromuscular complications that mainly include critical illness polyneuropathy (CIP), critical illness myopathy (CIM), and focal neuropathies. We examined the records of all paediatric patients with severe COVID-19 who were mechanically ventilated and experienced neuromuscular complications from our single tertiary centre between March 2020 and August 2021. During this period, 4/36 (11%) patients admitted to the paediatric ICU who were mechanically ventilated experienced neuromuscular complications (one CIM, two focal neuropathies, and one CIP associated with plexopathy). In three of them, the gamma genetic variant of SARS-CoV-2 was identified. At the 4-5 month follow-up, three of our patients exhibited slight clinical improvement. We conclude that paediatric patients with severe COVID-19 may present neuromuscular complications similar to adults (11%), and their medium-term prognosis seems unfavourable.

[Hypotonic infant]. / Síndrome hipotónico del recién nacido y lactante.

Hypotonia of the newborn or infant is defined as decreased resistance to passive movement and is a frequent diagnostic challenge in pediatric practice. The hypotonic syndrome is a working diagnosis and its etiology must be identified to determine associated morbidities, prognosis, and management. Rapid advances in bioinformatics and molecular genetic testing allow for early accurate diagnoses in the diagnostic process. Therefore, it is necessary to carry out an updated review on this topic. The objective of this non-systematic narrative review is to describe the diagnostic approach to hypotonic syndrome and its main etiologies. A review of the literature from PubMed and Scielo databases was carried out, including relevant articles in English and Spanish published in the last 15 years. We emphasize the value of the clinical examination and history in locating the cause of hypotonia (cen tral or peripheral) as the first step toward the etiological diagnosis. Systemic diseases such as sepsis, hypoxic-ischemic encephalopathy, heart failure, and metabolic and electrolyte abnormalities are still common causes of central hypotonia. Peripheral hypotonia involves disorders of the anterior horn of the spinal cord, peripheral nerve, neuromuscular junction and muscle, of inherited and acquired origin. The use of images of the central nervous system and muscle and genetic panels and exome, constitute the most recent contributions to the diagnosis of hypotonic syndrome. This article propo ses an initial approach based on the main clinical clues leading to a certain diagnosis. Its therapy is supportive, except for some conditions that require specific treatment.

Early onset neutral lipid storage disease with myopathy presenting as congenital hypotonia and hepatomegaly.

Neutral lipid storage disease with myopathy is an ultra-rare, inherited autosomal recessive neuromuscular metabolic disorder caused by pathogenic variants in PNPLA2. It typically presents in adults as a progressive myopathy and is associated with myocardiopathy, hepatic involvement, and high creatine kinase levels. Only three children and adolescents with neutral lipid storage disease with myopathy have been reported. We report a female infant with congenital hypotonia born to consanguineous parents, whose mother presented with polyhydramnios during pregnancy. She demonstrated delayed acquisition of motor milestones, hepatomegaly, and elevated creatine kinase levels. Homozygous pathogenic variants in PNPLA2 were identified. Lipid accumulation was observed within the muscle fibers and Jordans' anomaly was observed in a blood smear. This is the first report to describe an infant with mildly symptomatic neutral lipid storage disease with myopathy and demonstrate hepatic involvement in a pediatric patient. Despite her mild symptoms, her ancillary test results were markedly abnormal.

Encefalopatía necrotizante aguda asociada a influenza A / Influenza A-associated acute necrotizing encephalopathy

INTRODUCCIÓN: La encefalopatía necrotizante aguda (ENA) es una patología rara, caracterizada por compromiso de conciencia y presencia de múltiples lesiones encefálicas simétricas localizadas principalmente en tá lamo. Se asocia a alta letalidad e importantes secuelas. OBJETIVO: Describir el caso de un paciente escolar con ENA asociada a influenza-A con evolución favorable. CASO CLÍNICO: Paciente de 6 años de edad, con historia de 3 días de evolución de síntomas respiratorios altos asociados a fiebre (39 °C). Veinticuatro horas previo a la consulta destacaba compromiso de conciencia cualicuantitativo. Se realizó punción lumbar con proteinorraquia leve. En resonancia magnética (RM) se identificó focos de restricción a la difusión bilaterales de distribución simétrica, talámicos, en cuerpos mamila res, periacueductales, de tegmento pontino, hipocampales y en ambas cápsulas externas, asociado a componente hemorrágico y edema vasogénico, sugerente de ENA. Recibió tratamiento empírico con metilprednisolona y oseltamivir. Posteriormente, se recibió resultado positivo para virus influenza- AH1. Dado diagnóstico, se decidió administrar inmunoglobulina, evolucionando lento pero favora blemente. Al alta levemente bradipsíquico, con disminución de agudeza visual, lenguaje espontáneo y marcha con apoyo. A los 6 meses de seguimiento presentaba lenguaje y marcha normales, persis tiendo alteración visual a derecha. CONCLUSIÓN: Nuestro paciente presentó una ENA cuyo diagnóstico y manejo oportunos se asociaron a una favorable evolución neurológica en el largo plazo. Si bien la ENA es una patología infrecuente, la morbimortalidad asociada es altísima, por lo que resulta de gran importancia tener un alto grado de sospecha, a fin de solicitar estudio imagenológico dirigido, buscar causas infecciosas relacionadas e iniciar un manejo oportuno.

INTRODUCTION: Acute necrotizing encephalopathy of childhood (ANEC) is a rare disease characterized by alteration of consciousness and multiple symmetric brain lesions mainly involving the thalamus. It presents a high mortality rate and severe sequelae. OBJECTIVE: To describe a school-age patient with influenza A-related ANEC with favorable evolution. CLINICAL CASE: Six-year-old boy with 3 days history of upper respiratory symptoms and fever (39 °C). One day previous to admission, he presented altered state of consciousness. A lumbar puncture was performed, showing a mild increase of protein level in CSF. MRI showed bilateral foci of symmetric restricted signal in the thalamus, mammillary bodies, periaqueductal gray, ventral tegmentum, hippocampus, and in both external capsules, which was compatible with ANEC. The patient received empirical treatment with methylprednisolone and oseltamivir. Subsequently, a positive result was received for influenza. Considering diagnosis and severity of illness, it was decided to administer immunoglobulin. The patient got better slowly but favorably. At discharge, he still was mildly bradypsychic with decreased visual acuity, spontaneous speech and walking with assistance. At 6 months of follow-up, the patient presented normal speech and gait, with persistent visual impairment in the right eye. CONCLUSIONS: Our patient presented ANEC, whose timely diagnosis and management were associated with a favorable neurological evolution in the long term. Although ANEC is an infrequent pathology, it has very high morbidity and mortality rates, so it is very important to have a high degree of suspicion in order to request a targeted imaging study, search for related infectious causes, and start proper treatment.

Pediatric sciatic neuropathy: Clinical presentation and long term follow up. / Neuropatía ciática en pediatría: Presentación clínica y seguimiento a largo plazo.

INTRODUCTION: Sciatic neuropathy is rare and difficult to diagnose in pediatrics, and its long-term course has not been completely understood. OBJECTIVE: To analyze the clinical presentation and evolution of a group of pediatric patients with sciatic neuropathy. PATIENTS AND METHOD: Retrospective anal ysis of the clinical characteristics of pediatric patients with sciatic neuropathy treated in two hospitals of Santiago between 2014 and 2018. Locomotor examination, muscle trophism, deep tendon reflexes, gait, sensation, and pain were assessed. Sciatic nerve conduction study and electromyography (EMG) were performed, and magnetic resonance imaging (MRI) in three patients. RESULTS: Six patients were included with an average age of 11.8 years. The etiologies were traumatic (N = 2), by compression (N = 2), vascular (N = 1), and tumor (N = 1). All of the 6 patients presented foot drop and Achilles tendon hyporeflexia/areflexia, and 5 patients presented severe neuropathic pain. The EMG showed involvement of the sciatic nerve rami and dependent muscles. In two patients, a pelvic girdle and lower limbs MRI was performed, showing selective muscle involvement in sciatic territory. One patient underwent a lumbosacral plexus MRI, and subsequently histological study showing a benign neural tumor. Out of the three patients who were followed-up longer than one year presented motor sequelae and gait disorder. CONCLUSION: Sciatic neuropathy in the study group was secondary to different causes, predominantly traumatic and compressive etiologies. The three patients that were ina long-term follow-up presented significant motor sequelae. In most of the cases, neural injury wasassoci- ated with preventable causes, such as accidents and positioning in unconscious children, which is crucial in the prevention of a pathology with a high sequelae degree.

Guillain-Barré Syndrome and Hydrocephalus in an infant with Wiskott-Aldrich Syndrome. / Síndrome de Guillain Barré e hidrocefalia en un lactante con Síndrome de Wiskott Aldrich.

INTRODUCTION: Guillain-Barre Syndrome (GBS) is rarely diagnosed in the first year of life. The association of GBS with Wiskott-Aldrich syndrome (WAS) is even less frequent and has been previously reported in only two children to our knowledge. Hydrocephalus is a known but rare complication of GBS. OBJECTIVE: To describe the case of an infant in which GBS, WAS and hydrocephalus appear clinically associated. CLINICAL CASE: A nine-months-old male infant with a history of WAS was admitted to our ICU with acute hypotonia and poor general condition. He developed flaccid paralysis, absent deep tendon reflexes, and respiratory failure. A lumbar puncture showed albuminocytologic dissociation. GBS was suspected and an electromyography was performed, showing a demyelinating polyneuropathy. He was successfully treated with intravenous immunoglobulins. During hospitalization, he presented intermittent bradycardia, so a brain CT scan was performed, showing acute hydrocephalus which was managed through an external ventricular drain achieving favorable response. In the long term, the patient underwent bone marrow transplant and had to be reoperated due to valve-related complications. However, his psychomotor development is normal, with no obvious neurological sequelae. CONCLUSION: We present the third case of GBS in a patient with WAS, which is the first infant younger than one year. Additionally, he presented acute hydrocephalus as a complication of GBS. We suggest considering these three comorbidities since their early diagnosis and prompt management allow bet ter neurological recovery and avoid potentially lethal complications.

Non-dystrophic myotonia Chilean cohort with predominance of the SCN4A Gly1306Glu variant.

Non-dystrophic myotonias are a group of rare neuromuscular diseases linked to SCN4A or CLCN1. Among the subtypes, myotonia permanens, associated with the Gly1306Glu variant of SCN4A, is a relatively less frequent but more severe form. Most reports of non-dystrophic myotonias describe European populations. Therefore, to expand the genetic and phenotypic spectrum of this disorder, we evaluated 30 Chilean patients with non-dystrophic myotonias for associated variants and clinical characteristics. SCN4A variants were observed in 28 (93%) of patients, including 25 (83%) with myotonia permanens due to the Gly1306Glu variant. Myotonia permanens was inherited in 24 (96%) patients; the mean age of onset was 6 months, and the initial symptoms were orbicularis oculi myotonia in 17 (74%) patients and larynx myotonia in 12 (52%) patients. The extraocular muscles were involved in 11 (44%) patients, upper limbs in 20 (80%), and lower limbs in 21 (84%). Thirteen (52%) patients experienced recurrent pain and 10 (40%) patients reported limitations in daily life activities. Carbamazepine reduced myotonia in eight treated patients. The high frequency of the Gly1306Glu variant in SCN4A in Chilean patients suggests a founder effect and expands its phenotypic spectrum.

Neuropatía ciática en pediatría: presentación clínica y seguimiento a largo plazo / Pediatric sciatic neuropathy: clinical presentation and long term follow up

Resumen: Introducción: La neuropatía ciática es una entidad infrecuente y de difícil diagnóstico en Pediatría. Su evolución a largo plazo no ha sido claramente definida. Objetivo: Analizar la presentación clínica y evolución de un grupo de niños con neuropatía ciática. Pacientes y Método: Análisis retrospectivo de las características clínicas de pacientes pediátricos con neuropatía ciática atendidos en 2 hospitales de Santiago, entre 2014-2018. Se evaluó examen motor, trofismo muscular, reflejos osteotendíneos, marcha, sensibilidad y dolor. Se estudió neuroconducción de nervio ciático, electromiografía (EMG) y en 3 pacientes, Resonancia Magnética (RM). Resultados: Se incluyeron 6 pacientes, edad promedio 11,8 años. Hubo 2 causas traumáticas, 2 compresivas, 1 vascular y 1 tumoral. Los 6 pa cientes debutaron con pie caído e hiporreflexia/arreflexia aquiliana; 5 pacientes presentaron dolor neuropático severo. La EMG mostró en todos los casos compromiso en nervios y musculatura de pendientes del nervio ciático. En 2 casos se realizó RM de cintura pélvica y extremidades inferiores, mostrando compromiso muscular selectivo en pierna en territorio ciático. En 1 caso, se realizó RM de plexo lumbosacro, y luego estudio histológico, que concluyeron un tumor neural benigno. En los 3 pacientes que tuvieron seguimiento mayor a un año, se observaron secuelas motoras, con marcha alterada. Conclusión: La neuropatía ciática en este grupo fue secundaria a diversas etiologías, predominando las traumático-compresivas. En los 3 casos que tuvieron seguimiento a largo plazo se observaron secuelas motoras significativas. En la mayoría la lesión se asoció a causas prevenibles como accidentes y posicionamiento en niños con compromiso de conciencia, lo que resulta fundamental en la prevención de una patología con alto grado de secuelas.

Abstract: Introduction: Sciatic neuropathy is rare and difficult to diagnose in pediatrics, and its long-term course has not been completely understood. Objective: To analyze the clinical presentation and evolution of a group of pediatric patients with sciatic neuropathy. Patients and Method: Retrospective anal ysis of the clinical characteristics of pediatric patients with sciatic neuropathy treated in two hospitals of Santiago between 2014 and 2018. Locomotor examination, muscle trophism, deep tendon reflexes, gait, sensation, and pain were assessed. Sciatic nerve conduction study and electromyography (EMG) were performed, and magnetic resonance imaging (MRI) in three patients. Results: Six patients were included with an average age of 11.8 years. The etiologies were traumatic (N = 2), by compression (N = 2), vascular (N = 1), and tumor (N = 1). All of the 6 patients presented foot drop and Achilles tendon hyporeflexia/areflexia, and 5 patients presented severe neuropathic pain. The EMG showed involvement of the sciatic nerve rami and dependent muscles. In two patients, a pelvic girdle and lower limbs MRI was performed, showing selective muscle involvement in sciatic territory. One patient underwent a lumbosacral plexus MRI, and subsequently histological study showing a benign neural tumor. Out of the three patients who were followed-up longer than one year presented motor sequelae and gait disorder. Conclusion: Sciatic neuropathy in the study group was secondary to different causes, predominantly traumatic and compressive etiologies. The three patients that were ina long-term follow-up presented significant motor sequelae. In most of the cases, neural injury wasassoci- ated with preventable causes, such as accidents and positioning in unconscious children, which is crucial in the prevention of a pathology with a high sequelae degree.

Síndrome de Guillain Barré e hidrocefalia en un lactante con Síndrome de Wiskott Aldrich / Guillain-Barré Syndrome and Hydrocephalus in an infant with Wiskott-Aldrich Syndrome

Resumen: Introducción: El Síndrome de Guillain-Barré (SGB) es raramente diagnosticado en lactantes menores de 1 año. Su asociación con el Síndrome de Wiskott Aldrich (SWA), es aún menos frecuente, y ha sido previa mente reportada sólo en dos pacientes a nuestro conocimiento. La hidrocefalia, es una complicación conocida, pero infrecuente del SGB. Objetivo: presentar el caso clínico de un lactante en el que se asocian las patologías de SGB, SWA e hidrocefalia. Caso Clínico: varon de 9 meses, portador de SWA hospitalizado en unidad de cuidados intensivos por hipotonía aguda y compromiso del estado gene ral. Evolucionó con parálisis fláccida, falla ventilatoria y arreflexia generalizada. Una punción lumbar mostró disociación albuminocitológica, y el estudio electrofisiológico mostró signos de polineuropatía desmielinizante severa. Se trató con inmunoglobulina, evolucionando en forma satisfactoria. Por bradicardia intermitente, se realizó tomografla axial computada cerebral (TAC), que mostró signos de una hidrocefalia aguda, manejada mediante válvula derivativa ventrículo peritoneal con favorable respuesta. En el largo plazo, se sometió a trasplante de médula ósea y debió ser reintervenido por complicaciones valvulares, sin embargo, su desarrollo psicomotor es normal sin secuelas neurológi cas evidentes hasta los 3 años. Conclusión: Presentamos el tercer caso de SGB en un paciente porta dor de SWA, destacando ser el primero de ellos en un lactante menor de 1 año. Adicionalmente, este niño presentó una hidrocefalia aguda como complicación del SGB. Consideramos relevante tener presente estas comorbilidades, debido a que su pronto diagnóstico y manejo oportuno, permiten una mejor recuperación neurológica y evitan complicaciones potencialmente letales.

Abstract: Introduction: Guillain-Barre Syndrome (GBS) is rarely diagnosed in the first year of life. The association of GBS with Wiskott-Aldrich syndrome (WAS) is even less frequent and has been previously reported in only two children to our knowledge. Hydrocephalus is a known but rare complication of GBS. Objective: To describe the case of an infant in which GBS, WAS and hydrocephalus appear clinically associated. Clinical Case: A nine-months-old male infant with a history of WAS was admitted to our ICU with acute hypotonia and poor general condition. He developed flaccid paralysis, absent deep tendon reflexes, and respiratory failure. A lumbar puncture showed albuminocytologic dissociation. GBS was suspected and an electromyography was performed, showing a demyelinating polyneuropathy. He was successfully treated with intravenous immunoglobulins. During hospitalization, he presented intermittent bradycardia, so a brain CT scan was performed, showing acute hydrocephalus which was managed through an external ventricular drain achieving favorable response. In the long term, the patient underwent bone marrow transplant and had to be reoperated due to valve-related complications. However, his psychomotor development is normal, with no obvious neurological sequelae. Conclusion: We present the third case of GBS in a patient with WAS, which is the first infant younger than one year. Additionally, he presented acute hydrocephalus as a complication of GBS. We suggest considering these three comorbidities since their early diagnosis and prompt management allow bet ter neurological recovery and avoid potentially lethal complications.

[Influenza A-associated acute necrotizing encephalopathy]. / Encefalopatía necrotizante aguda asociada a influenza A.

INTRODUCTION: Acute necrotizing encephalopathy of childhood (ANEC) is a rare disease characterized by alteration of consciousness and multiple symmetric brain lesions mainly involving the thalamus. It presents a high mortality rate and severe sequelae. OBJECTIVE: To describe a school-age patient with influenza A-related ANEC with favorable evolution. CLINICAL CASE: Six-year-old boy with 3 days history of upper respiratory symptoms and fever (39 °C). One day previous to admission, he presented altered state of consciousness. A lumbar puncture was performed, showing a mild increase of protein level in CSF. MRI showed bilateral foci of symmetric restricted signal in the thalamus, mammillary bodies, periaqueductal gray, ventral tegmentum, hippocampus, and in both external capsules, which was compatible with ANEC. The patient received empirical treatment with methylprednisolone and oseltamivir. Subsequently, a positive result was received for influenza. Considering diagnosis and severity of illness, it was decided to administer immunoglobulin. The patient got better slowly but favorably. At discharge, he still was mildly bradypsychic with decreased visual acuity, spontaneous speech and walking with assistance. At 6 months of follow-up, the patient presented normal speech and gait, with persistent visual impairment in the right eye. CONCLUSIONS: Our patient presented ANEC, whose timely diagnosis and management were associated with a favorable neurological evolution in the long term. Although ANEC is an infrequent pathology, it has very high morbidity and mortality rates, so it is very important to have a high degree of suspicion in order to request a targeted imaging study, search for related infectious causes, and start proper treatment.

Diagnosis and Management of Carpal Tunnel Syndrome in Children with Mucopolysaccharidosis: A 10 Year Experience.

INTRODUCTION: Mucopolysaccharidoses (MPS) are rare and clinically heterogeneous lysosomal storage disorders. Carpal tunnel syndrome (CTS) is a frequent complication in MPS types I, II, VI, and VII. CTS symptoms are difficult to recognize in these children, and often there is a lack of appropriate investigations. PATIENTS AND METHODS: In this retrospective study, all MPS patients were referred to the electrodiagnostic (EDX) laboratory of a single academic center during a 10-year period. Forty-eight children underwent serial EDX studies for CTS diagnosis and follow-up after surgery. Forty-two patients were diagnosed with CTS. Sensory nerve conduction velocity (SNCV), distal motor latency (DML), and motor nerve conduction velocity through the wrist (MNCV-W) of the median nerve were reviewed and analyzed. RESULTS: One-hundred-three EDX examinations were performed on 48 patients. The median age at disease diagnosis was 2.1 years versus 4.9 years for CTS diagnosis. Analysis of the series revealed that electrophysiological abnormalities of CTS could have started much earlier (before the age of 2 years or at diagnosis of MPS). Diagnosis was based on SNCV and DML results, and MNCV-W was taken into consideration. Bilateral CTS was frequent (88%) in the types of MPS studied in our population and was observed from the first year of life, and may not have be associated with obvious clinical symptoms. EDX studies also helped in the follow-up and detection of CTS relapses, thus leading to an early intervention allowing a better recovery. CONCLUSION: EDX studies should be performed promptly and regularly in these patients. Prospective studies are required in order to understand the effect of disease-specific therapies in preventing the development of CTS in these patients. SYNOPSIS: EDX studies should be performed in MPS patients soon after diagnosis and during routine follow-up, before and after surgical decompression.

[Fibrodysplasia ossificans progressiva. Report of one case]. / Fibrodisplasia osificante progresiva plus por una variante patogénica del gen ACVR1: Caso clínico.

Fibrodysplasia ossificans progressiva (FOP) or myositis ossificans, is a genetic disease, with a prevalence of 1 in 2.000.000. It is caused by pathogenic variants in ACVR1 gene and characterized by soft tissue heterotopic ossification, starting in the second decade of life. It is associated to early mortality caused by respiratory complications. It evolves in flare-ups, triggered by soft tissue injuries; therapy is symptomatic, using analgesia, steroids and diphosphonates. We report a 12-year-old female with left renal agenesis, hallux valgus and intellectual disability, presenting with a six months history of thoracic kyphosis, tender nodules in the thorax, and rigidity of right elbow and left knee. Clinical examination revealed dysmorphic facial features. A magnetic resonance showed heterotopic ossification nodules, which was confirmed with spinal radiography. These findings prompted the diagnosis of FOP. Pain treatment was started, and prednisone was used during flare-ups. The ACVR1 gene was analyzed and a pathogenic variant, p. Arg206His, was found, confirming the diagnosis of FOP.

Fibrodisplasia osificante progresiva plus por una variante patogénica del gen ACVR1: caso clínico / Fibrodysplasia ossificans progressiva: report of one case

Fibrodysplasia ossificans progressiva (FOP) or myositis ossificans, is a genetic disease, with a prevalence of 1 in 2.000.000. It is caused by pathogenic variants in ACVR1 gene and characterized by soft tissue heterotopic ossification, starting in the second decade of life. It is associated to early mortality caused by respiratory complications. It evolves in flare-ups, triggered by soft tissue injuries; therapy is symptomatic, using analgesia, steroids and diphosphonates. We report a 12-year-old female with left renal agenesis, hallux valgus and intellectual disability, presenting with a six months history of thoracic kyphosis, tender nodules in the thorax, and rigidity of right elbow and left knee. Clinical examination revealed dysmorphic facial features. A magnetic resonance showed heterotopic ossification nodules, which was confirmed with spinal radiography. These findings prompted the diagnosis of FOP. Pain treatment was started, and prednisone was used during flare-ups. The ACVR1 gene was analyzed and a pathogenic variant, p. Arg206His, was found, confirming the diagnosis of FOP.

Carnitine palmitoyltransferase type 2 deficiency: novel mutation in a Native South American family with whole-body muscle magnetic resonance imaging findings: two case reports.

BACKGROUND: The myopathic form of carnitine palmitoyltransferase type II deficiency is an inherited autosomal recessive metabolic myopathy usually starting in childhood. Most reports have been on European and Japanese populations, and no Native South American patients have been reported to date. The p.Ser113Leu mutation is the most frequent in the European population. Only lower-leg magnetic resonance imaging findings have been reported, with gluteus maximus involvement in one case and normal imaging in other patients. CASE PRESENTATION: Two Native South American siblings, a boy and a girl, presented to our neuromuscular clinic with recurrent rhabdomyolysis associated with transient muscle weakness after prolonged exercise. During episodes, their creatine kinase concentrations were markedly increased, up to 148,000 (1.48 × 105) IU/L in the boy and 18,000 (1.8 × 104) IU/L in the girl. The results of electroneuromyography and histopathology suggested a nonspecific myopathy. CPT2 gene sequencing showed two heterozygous mutations: the p.Ser113Leu variant and a novel one (predicted to be deleterious by in silico analysis), the p.Ser373Pro variant. The patients' parents were asymptomatic carriers. Whole-body magnetic resonance imaging showed mild selective involvement in the thoracic extensors and pelvic girdle in both siblings, and in the thighs and lower legs in one of them. Dietary and bezafibrate treatment was started, and symptomatic relief was observed. CONCLUSIONS: To the best of our knowledge, this is the first reported Native South American family with a CPT2 deficiency carrying a novel mutation and particular features visualized by whole-body magnetic resonance imaging.

Whole-body muscle magnetic resonance imaging in SEPN1-related myopathy shows a homogeneous and recognizable pattern.

INTRODUCTION: The aim of this study was to delineate the spectrum of muscle involvement in patients with a myopathy due to mutations in SEPN1 (SEPN1-RM). METHODS: Whole-body magnetic resonance imaging (WBMRI) was used in 9 patients using T1-weighted turbo spin-echo (T1-TSE) sequences and short tau inversion recovery (STIR) in 5 patients. RESULTS: Analysis of signal and volume abnormalities by T1-TSE sequences in 109 muscles showed a homogeneous pattern characterized by a recognizable combination of atrophy and signal abnormalities in selected muscles of the neck, trunk, pelvic girdle, and lower limbs. Severe wasting of sternocleidomastoid muscle and atrophy of semimembranosus were detected. Selective paraspinal, gluteus maximus, and thigh muscle involvement was also observed. The lower leg was less constantly affected. CONCLUSIONS: WBMRI scoring of altered signal and atrophy in muscle can be represented by heatmaps and is associated with a homogeneous, recognizable pattern in SEPN1-RM, distinct from other genetic muscle diseases.

Whole body muscle MRI protocol: pattern recognition in early onset NM disorders.

A paediatric and adult whole-body MRI (WB-MRI) protocol using a 1.5-T MRI system was used to examine 117 individuals (106 patients, 11 asymptomatic relatives). Genetic diagnosis was obtained in 38 subjects (RYR1, LMNA, COL6, DNM2, GAA, TPM2, SGCA, MYH7, NEB, SMN, FKBP14). T1-TSE WB-MRI sequences were abnormal in 67% of patients and 27% of asymptomatic relatives. Multiple striped signal abnormalities ('tiger-like') were very specific for COLVI-related myopathy. Distinct involvement of muscles in the head, neck, trunk, girdles and limbs was observed in patients with RYR1, SEPN1, GAA, LMNA or TPM2 mutations. Abnormalities and pattern recognition were more frequent in patients studied due to rigid spine syndrome (80% abnormal, recognisable in 75% of cases), hyperlaxity syndrome (75%; 50%) or with confirmed myopathy but absence of these markers (71%; 40%). Pattern was consistent with the molecular diagnosis in 97%. Mild clinical involvement was revealed by muscle testing in three parents with abnormal WB-MRI. The Garches WB-MRI protocol is suitable for a large spectrum of adults and children with early-onset neuromuscular disorders and can be used as an effective screening test in relatives. Recognition of characteristic patterns of abnormalities is improved by whole-body scanning compared with sequential MRI and, therefore, diagnostic impact is greater.