The comparison of spread of methylene blue after the Pericapsular Nerve Group block and a double injection selectively targeting the articular branches to the anterior hip capsule in human cadavers.

Objectives: In this study, the spread of methylene blue was compared between an ultrasound-guided Pericapsular Nerve Group (PENG) block and a double injection technique, where the approach towards the inferomedial acetabulum was added to the latter.

Methods: The two techniques were performed in 11 fresh frozen cadavers. The spread was measured after anatomical dissection in which the supplying femoral and obturator nerves were identified.

Myopathic manifestations across the adult lifespan of patients with malignant hyperthermia susceptibility: a narrative review.

Malignant hyperthermia susceptibility (MHS) designates individuals at risk of developing a hypermetabolic reaction triggered by halogenated anaesthetics or the depolarising neuromuscular blocking agent suxamethonium. Over the past few decades, beyond the operating theatre, myopathic manifestations impacting daily life are increasingly recognised as a prevalent phenomenon in MHS patients. At the request of the European Malignant Hyperthermia Group, we reviewed the literature and gathered the opinion of experts to define MHS-related myopathy as a distinct phenotype expressed across the adult lifespan of MHS patients unrelated to anaesthetic exposure; this serves to raise awareness about non-anaesthetic manifestations, potential therapies, and management of MHS-related myopathy.

Vascular Ehlers-Danlos Syndrome: A Comprehensive Natural History Study in a Dutch National Cohort of 142 Patients.

Background: Vascular Ehlers-Danlos syndrome (vEDS) is a rare connective tissue disorder with a high risk for arterial, bowel, and uterine rupture, caused by heterozygous pathogenic variants in . The aim of this cohort study is to provide further insights into the natural history of vEDS and describe genotype-phenotype correlations in a Dutch multicenter cohort to optimize patient care and increase awareness of the disease.

Methods: Individuals with vEDS throughout the Netherlands were included.

Functional analysis of cell lines derived from SMAD3-related Loeys-Dietz syndrome patients provides insights into genotype-phenotype relation.

Rationale: Pathogenic (P)/likely pathogenic (LP) SMAD3 variants cause Loeys-Dietz syndrome type 3 (LDS3), which is characterized by arterial aneurysms, dissections and tortuosity throughout the vascular system combined with osteoarthritis.

Objectives: Investigate the impact of P/LP SMAD3 variants with functional tests on patient-derived fibroblasts and vascular smooth muscle cells (VSMCs), to optimize interpretation of SMAD3 variants.

Methods: A retrospective analysis on clinical data from individuals with a P/LP SMAD3 variant and functional analyses on SMAD3 patient-derived VSMCs and SMAD3 patient-derived fibroblasts, differentiated into myofibroblasts.

Muscle Ultrasound Abnormalities in Individuals with RYR1-Related Malignant Hyperthermia Susceptibility.

Background: Variants in RYR1, the gene encoding the ryanodine receptor-1, can give rise to a wide spectrum of neuromuscular conditions. Muscle imaging abnormalities have been demonstrated in isolated cases of patients with a history of RYR1-related malignant hyperthermia (MH) susceptibility.

Objective: To provide insights into the type and prevalence of muscle ultrasound abnormalities and muscle hypertrophy in patients carrying gain-of-function RYR1 variants associated with MH susceptibility and to contribute to delineating the wider phenotype, optimizing the diagnostic work-up and care for MH susceptible patients.

Neuromuscular symptoms in patients with -related malignant hyperthermia and rhabdomyolysis.

Malignant hyperthermia and exertional rhabdomyolysis have conventionally been considered episodic phenotypes that occur in otherwise healthy individuals in response to an external trigger. However, recent studies have demonstrated a clinical and histopathological continuum between patients with a history of malignant hyperthermia susceptibility and/or exertional rhabdomyolysis and -related congenital myopathies. We hypothesize that patients with a history of -related exertional rhabdomyolysis or malignant hyperthermia susceptibility do have permanent neuromuscular symptoms between malignant hyperthermia or exertional rhabdomyolysis episodes.

High-yield identification of pathogenic NF1 variants by skin fibroblast transcriptome screening after apparently normal diagnostic DNA testing.

Neurofibromatosis type 1 (NF1) is caused by inactivating mutations in NF1. Due to the size, complexity, and high mutation rate at the NF1 locus, the identification of causative variants can be challenging. To obtain a molecular diagnosis in 15 individuals meeting diagnostic criteria for NF1, we performed transcriptome analysis (RNA-seq) on RNA obtained from cultured skin fibroblasts.

Functional analysis of RYR1 variants in patients with confirmed susceptibility to malignant hyperthermia.

Background: A major bottleneck to the introduction of noninvasive presymptomatic diagnostic tests for the pharmacogenetic disorder malignant hyperthermia is the lack of functional data for associated variants.

Methods: We screened 50 genes having a potential role in skeletal muscle calcium homeostasis using the HaloPlex™ (Agilent Technologies, Santa Clara, CA, USA) target enrichment system and next-generation sequencing. Twenty-one patients with a history of a clinical malignant hyperthermia reaction together with a positive in vitro contracture test were included.

Targeted transcript analysis in muscles from patients with genetically diverse congenital myopathies.

Congenital myopathies are a group of early onset muscle diseases of variable severity often with characteristic muscle biopsy findings and involvement of specific muscle types. The clinical diagnosis of patients typically relies on histopathological findings and is confirmed by genetic analysis. The most commonly mutated genes encode proteins involved in skeletal muscle excitation-contraction coupling, calcium regulation, sarcomeric proteins and thin-thick filament interaction.

Perioperative Care for Patients with Neuromuscular Disorders in the Netherlands - A Questionnaire Study Among Anaesthesiologists, Neurologists and Clinical Geneticists.

Background: Patients with neuromuscular disorders are at increased risk of suffering perioperative complications. Current knowledge concerning this topic is based on small retrospective studies and expert opinion. Therefore, an individualized multidisciplinary approach to perioperative anaesthesia planning is invaluable to anticipate difficulties and to optimize outcomes.

Expanding the genetic and phenotypic spectrum of ACTA2-related vasculopathies in a Dutch cohort.

Purpose: Heterozygous pathogenic/likely pathogenic (P/LP) variants in the ACTA2 gene confer a high risk for thoracic aortic aneurysms and aortic dissections. This retrospective multicenter study elucidates the clinical outcome of ACTA2-related vasculopathies.

Methods: Index patients and relatives with a P/LP variant in ACTA2 were included.

Mapping the current evidence on the anesthetic management of adult patients with neuromuscular disorders-a scoping review.

Purpose: Patients with neuromuscular disorders (NMDs) are at increased risk of perioperative complications. The objective of this scoping review was to examine emerging evidence from published studies, case reports, and review articles on anesthetic management of patients with NMDs, following the methodological frame for scoping reviews.

Sources: We searched PubMed and EMBASE for articles published between 1 January 2000 and 14 July 2021.

Referral Indications for Malignant Hyperthermia Susceptibility Diagnostics in Patients without Adverse Anesthetic Events in the Era of Next-generation Sequencing.

Background: The introduction of next-generation sequencing into the diagnosis of neuromuscular disorders has resulted in an increased number of newly identified RYR1 variants. The hypothesis was that there is an increased referral of patients to malignant hyperthermia units without a personal/family history of adverse anesthetic events suspected to be malignant hyperthermia. This retrospective multicenter cohort study evaluates patient referral indications and outcomes for those without a history of an adverse anesthetic event.

Malignant Hyperthermia During Cardiac Surgery Successfully Treated by Deep Hypothermia Using Cardiopulmonary Bypass: A Case Report.

Malignant hyperthermia (MH) is a life-threatening hypermetabolic disorder triggered by volatile anesthetics and/or succinylcholine. We report a case of a 58-year-old patient with a type-A aortic dissection. After induction of general anesthesia, a hypermetabolic reaction was successfully treated by deep hypothermia using cardiopulmonary bypass.

The neuromuscular and multisystem features of RYR1-related malignant hyperthermia and rhabdomyolysis: A study protocol.

Introduction: Malignant hyperthermia (MH) and exertional rhabdomyolysis (ERM) have long been considered episodic phenotypes occurring in response to external triggers in otherwise healthy individuals with variants in RYR1. However, recent studies have demonstrated a clinical and histopathological continuum between patients with RYR1-related congenital myopathies and those with ERM or MH susceptibility. Furthermore, animal studies have shown non-neuromuscular features such as a mild bleeding disorder and an immunological gain-of-function associated with MH/ERM related RYR1 variants raising important questions for further research.

HyperCKemia and rhabdomyolysis in the neuroleptic malignant and serotonin syndromes: A literature review.

Neuroleptic malignant syndrome and serotonin syndrome are two syndromes whose molecular bases remain poorly understood. The phenotypes of both syndromes overlap with other syndromes that have a clear genetic background, in particular RYR1-related malignant hyperthermia. Through a literature review, performed according to the PRISMA guidelines, we aimed to report the clinical features of both syndromes, and the results of genetic testing performed.