Hypokalemic periodic paralysis: a 3-year follow-up study.

Background And Objectives: Primary hypokalemic periodic paralysis (HypoPP) is an inherited channelopathy most commonly caused by mutations in CACNA1S. HypoPP can present with different phenotypes: periodic paralysis (PP), permanent muscle weakness (PW), and mixed weakness (MW) with both periodic and permanent weakness. Little is known about the natural history of HypoPP.

Quantitative Muscle MRI and Clinical Findings in Women With Pathogenic Dystrophin Gene Variants.

To explore fat replacement, muscle strength, and clinical features in women heterozygous for a pathogenic variant, we prospectively examined 53 women, assuming that some of these women-despite of the recessive X-linked inheritance-manifested clinical symptoms. We performed a cross-sectional observational study using MRI and stationary dynamometry of lower extremities, extracted blood muscle biomarkers, and investigated subjective complaints. Results were compared with 19 healthy women.

Energy metabolism during exercise in patients with β-enolase deficiency (GSDXIII).

Aim: To investigate the in vivo skeletal muscle metabolism in patients with β-enolase deficiency (GSDXIII) during exercise, and the effect of glucose infusion.

Methods: Three patients with GSDXIII and 10 healthy controls performed a nonischemic handgrip test as well as an incremental cycle ergometer test measuring maximal oxidative consumption (VO) and a 1-hour submaximal cycle test at an intensity of 65% to 75% of VO. The patients repeated the submaximal exercise after 2 days, where they received a 10% iv-glucose supplementation.

Prolonged fasting-induced hyperketosis, hypoglycaemia and impaired fat oxidation in child and adult patients with spinal muscular atrophy type II.

Aim: This study explored hypoglycaemia and metabolic crises, including hyperketosis, in patients with spinal muscular atrophy (SMA).

Methods: The study comprised four adolescents aged 15-17 and six adults aged 19-37 with SMA type II and eight adult controls aged 21-41, who were recruited by the Rigshospitalet, Denmark, from May 1st to October 30th 2017. We used stable isotope technique and indirect calorimetry to investigate fat and glucose metabolism during a 24-h fast or until hypoglycaemia occurred.

Contractile properties are impaired in congenital myopathies.

The ratio between muscle strength and muscle cross-sectional area is called the specific force. Fatty replacement of muscles is seen in many myopathies, affecting the specific force, without necessarily affecting the ability of the remaining muscle fibers to contract. This ability is called the contractility and is the ratio between muscle strength and the lean muscle cross-sectional area, i.

Permanent muscle weakness in hypokalemic periodic paralysis.

Objective: To map the phenotypic spectrum in 55 individuals with mutations in known to cause hypokalemic periodic paralysis (HypoPP) using medical history, muscle strength testing, and muscle MRI.

Methods: Adults with a mutation in known to cause HypoPP were included. Medical history was obtained.

Growth and differentiation factor 15 as a biomarker for mitochondrial myopathy.

Objective: We investigated if Growth and Differentiation Factor 15 (GDF-15) can be used as a biomarker to distinguish patients with mitochondrial myopathy from patients with other myopathies.

Methods: Serum GDF-15 was measured in 28 patients with mitochondrial disease, 24 with metabolic myopathies, 27 with muscular dystrophy and 21 healthy controls.

Results And Conclusions: Our findings indicate that elevated GDF-15 can distinguish patients with mitochondrial myopathy from other myopathies, including metabolic myopathies.

Fat oxidation is impaired during exercise in lipin-1 deficiency.

Objective: To investigate substrate metabolism during exercise in an adult with lipin-1 deficiency, an inherited defect in lipid homeostasis, and to study the effect of glucose supplementation on his exercise tolerance.

Methods: We studied a 48-year-old man with lipin-1 deficiency and 2 healthy men. The patient has exercise intolerance and monthly episodes of rhabdomyolysis.

Expanding the phenotype of filamin-C-related myofibrillar myopathy.

We report three patients with a rare filamin C myofibrillar myopathy. They present with atypical symptoms that expand the phenotype of filaminopathy. The new findings are progressive contractures of muscles surrounding the temporomandibular joint, detailed single myofiber histology findings and demonstration of severe affection of paraspinal muscles on MRI.