Stepwise approach to myopathy in systemic disease

The Broad Spectrum of Gallbladder Paraneoplastic Syndromes

Gallbladder carcinoma (GBC) is a rare gastrointestinal tumor with a reported incidence of 1 in 100,000 in the United States. GBC may present with subtle signs and symptoms that can be missed on routine examination and/or confused with other conditions. Unfortunately, its subtle presentation frequently leads to late diagnosis and, thus, a poor prognosis. Several paraneoplastic syndromes have been associated with GBC. Despite their strong associations with neoplastic disease, the precise pathophysiologic mechanisms underlying the development of these syndromes remain poorly understood. Given the vague nature of their initial signs and symptoms, these syndromes are frequently diagnosed as independent entities and only later associated with occult malignancies that may have already metastasized to other organs. Physicians need to be aware of the signs and symptoms of these paraneoplastic syndromes and include an underlying malignancy as part of the differential diagnosis. This review provides a detailed discussion of the paraneoplastic syndromes associated with GBC.

Developing In Vitro Models to Define the Role of Direct Mitochondrial Toxicity in Frequently Reported Drug-Induced Rhabdomyolysis

The United States Food and Drug Administration Adverse Event Reporting System (FAERS) logged 27,140 rhabdomyolysis cases from 2004 to 31 March 2020. We used FAERS to identify 14 drugs frequently reported in 6583 rhabdomyolysis cases and to investigate whether mitochondrial toxicity is a common pathway of drug-induced rhabdomyolysis by these drugs. Preliminary screening for mitochondrial toxicity was performed using the acute metabolic switch assay, which is adapted here for use in murine L6 cells. Fenofibrate, risperidone, pregabalin, propofol, and simvastatin lactone drugs were identified as mitotoxic and underwent further investigation, using real-time respirometry (Seahorse Technology) to provide more detail on the mechanism of mitochondrial-induced toxicity. To confirm the human relevance of the findings, fenofibrate and risperidone were evaluated in primary human skeletal muscle-derived cells (HSKMDC), using the acute metabolic switch assay and real-time respirometry, which confirmed this designation, although the toxic effects on the mitochondria were more pronounced in HSKMDC. Overall, these studies demonstrate that the L6 model of acute modification may find utility as an initial, cost-effective screen for identifying potential myotoxicants with relevance to humans and, importantly, that drug-induced mitochondrial dysfunction may be a common mechanism shared by some drugs that induce myotoxicity.

[Creatine phosphokinase enzyme elevation in two third-level hospitals of Córdoba]

Introduction

HyperCKemia is defined as the elevation of creatine phosphokinase (CK) levels greater than 1.5 times the upper limit (CK>285 U/L), being produced by multiple causes, which vary according different populations. The main objective of the study was to know the frequency of hyperCKemia in two hospitals in Córdoba and its main causes.

Methods

Retrospective analytical study in two hospitals in Córdoba, Argentina, where all patients over 18 years of age who presented CK values ​​greater than 285 U/L on at least 2 occasions in a period between 1 and 4 weeks were identified, between the years 2015 and 2017.

Results

254 patients with hyperCKemia were identified, the majority were male (n=181, 71.3%) and their median age was 65 years (interquartile range 25-75%=50-73 years). The main causes of hyperCKemia were ischemic myopathy in 99 (39%) patients and drug-induced myopathies in 45 (17.7%), with statins being the most frequently involved drugs in 31 cases. In only 3.1% of the cases the final diagnosis was not reached. Drug-induced hyperCKemias, when compared to other causes, occurred more frequently in patients with a history of chronic kidney disease (9/45 [20%] vs 18/209 [8.6%], p = 0.025) and in non-smokers (41/45 [91.1%] vs. 157/209 [75.1%], p=0.019).

Main conclusion

254 cases of hyperCKemia were observed, the main causes being of ischemic origin and secondary to drug use, especially statins.

Exogenous Antioxidants in Remyelination and Skeletal Muscle Recovery

Inflammatory, oxidative, and autoimmune responses cause severe damage to the nervous system inducing loss of myelin layers or demyelination. Even though demyelination is not considered a direct cause of skeletal muscle disease there is extensive damage in skeletal muscles following demyelination and impaired innervation. In vitro and in vivo evidence using exogenous antioxidants in models of demyelination is showing improvements in myelin formation alongside skeletal muscle recovery. For instance, exogenous antioxidants such as EGCG stimulate nerve structure maintenance, activation of glial cells, and reduction of oxidative stress. Consequently, this evidence is also showing structural and functional recovery of impaired skeletal muscles due to demyelination. Exogenous antioxidants mostly target inflammatory pathways and stimulate remyelinating mechanisms that seem to induce skeletal muscle regeneration. Therefore, the aim of this review is to describe recent evidence related to the molecular mechanisms in nerve and skeletal muscle regeneration induced by exogenous antioxidants. This will be relevant to identifying further targets to improve treatments of neuromuscular demyelinating diseases.

Proximal myopathy: causes and associated conditions

Proximal myopathy presents as generalized muscle weakness commonly involving the muscles of upper and/or lower limbs. Toxins, long-term use of statins, corticosteroids, alcohol, SGLT2 inhibitors, COVID-19 vaccination, and antimalarials have been attributed to its development. In endocrine and metabolic disorders, adrenal dysfunction including both overproduction and insufficiency of the adrenal gland hormones has been reported to cause myopathy. Moreover, parathyroid and thyroid disorders along with pituitary gland disorders can also directly or indirectly contribute to this condition. In idiopathic inflammatory myopathies including polymyositis, dermatomyositis, inclusion body myositis (IBM), and Systemic Lupus Erythematosus (SLE), Sjögren's Syndrome, and overlap syndromes, moderate to severe muscle weakness has been observed. IBM has been reported to be the most prevalent acquired myopathy above the age of 50. Hereditary or congenital myopathies include limb girdle muscular dystrophies, facioscapulohumeral muscular dystrophy, Duchenne and Becker muscular dystrophy, and proximal myotonic myopathy. In addition to these, glycogen storage diseases such as the McArdle disease can also cause fast exhaustion, myalgia, and cramping in working muscles. It is pertinent to mention here that a class of hereditary metabolic myopathies, referred to as "lipid deposition myopathy" causes lipids to accumulate in skeletal muscle fibers, leading to lesions and degeneration. Among viral causes, HIV, dengue virus, influenza virus, hepatitis B virus, hepatitis C virus, SARS-CoV2 are also associated with muscle weakness. Sarcoidosis, an inflammatory disease, can also manifest as muscle weakness and myalgia. Owing to this complicated pathophysiology of proximal myopathy, this review aims to summarize the existing literature on conditions associated with this phenomenon and other recent developments that have been made regarding events leading to development of generalized muscle weakness. To the authors' knowledge this is the first narrative review that discusses causes and conditions associated with proximal myopathy in thorough detail.

Clinical and pathological features of immune-mediated necrotising myopathies in a single-centre muscle biopsy cohort

OBJECTIVE

Immune-mediated necrotising myopathy (IMNM) is a subset of idiopathic inflammatory myopathies (IIM) characterized by significantly elevated creatine kinase level, muscle weakness and predominant muscle fibre necrosis in muscle biopsy. This study aimed to investigate the clinical and pathological characteristics of patients with IMNM in a single-centre muscle biopsy cohort.

METHODS

A total of 860 patients who had muscle biopsy reports in our centre from May 2008 to December 2017 were enrolled in this study. IMNM was diagnosed according to the 2018 European Neuromuscular Centre (ENMC) clinicopathological diagnostic criteria for IMNM.

RESULTS

The muscle biopsy cohort consisted of 531 patients with IIM (61.7%), 253 patients with non-IIM (29.4%), and 76 undiagnosed patients (8.8%). IIM cases were classified as IMNM (68[7.9%]), dermatomyositis (346[40.2%]), anti-synthetase syndrome (82[9.5%]), polymyositis (32[3.7%]), and sporadic inclusion body myositis (3[0.3%]). Limb girdle muscular dystrophy (LGMD) 2B and lipid storage myopathy (LSM) are the two most common non-IIM disorders in our muscle biopsy cohort. IMNM patients had a higher onset age (41.57 ± 14.45 vs 21.66 ± 7.86 and 24.56 ± 10.78, p < .0001), shorter duration (21.79 ± 26.01 vs 66.69 ± 67.67 and 24.56 ± 10.78, p < .0001), and more frequent dysphagia (35.3% vs. 3.4 and 6.3%, p = .001) than LGMD 2B and LSM patients. Muscle biopsy from IMNM showed more frequent muscle fibre necrosis (95.6% vs 72.4 and 56.3%, p < .0001), overexpression of major histocompatibility complex-I on sarcolemma (83.8% vs 37.9 and 12.9%, p < .0001), and CD4+ T cell endomysia infiltration (89.7% vs 53.6 and 50%, p < .0001) compared with those from LGMD 2B and LSM patients.

CONCLUSIONS

It is easy to distinguish IMNM from other IIM subtypes according to clinical symptoms and myositis specific antibodies profiles. However, distinguishing IMNM from disorders clinically similar to non-IIM needs combined clinical, serological and pathological features.

Association of acute hepatitis B and acute myopathy: a case report

BACKGROUND

Hepatitis B virus infection is a global public health problem. Although hepatitis B virus primarily affects hepatocytes, it sometimes develops disease manifestations outside the liver, such as myopathy, which is commonly caused by chronic hepatitis B.

CASE PRESENTATION

This case report describes a 57-year-old Iranian woman admitted to the hospital with jaundice, fever, body itching, abdominal pain, progressive muscle weakness, icteric sclera, right upper quadrant pain, and decreased muscle force. Examination on the first day of admission revealed that the patient was negative for hepatitis D antibody, positive for hepatitis B core (IgM) antibody, positive for hepatitis B surface antigen, and negative for hepatitis B e antibody but positive for hepatitis B e antigen. Moreover, she showed high levels of hepatitis B virus DNA viral load, creatine kinase, lactate dehydrogenase, serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminase, total bilirubin, direct bilirubin, and alkaline phosphatase, and electromyography/nerve conduction velocity showed acute myopathic process.

CONCLUSIONS

Interestingly, myopathy symptoms improved after improving hepatitis symptoms and decreasing hepatitis B viral load, suggesting a close association between hepatitis B infection and myopathy.

Proximal Myopathy With Hypercalcemic Crisis and Papillary Thyroid Carcinoma in a 38-Year-Old Female

Although proximal myopathy is a well-known manifestation of primary hyperparathyroidism (PHP), it is usually not the first one. Here, we present the case of a 38-year-old female who presented to the neurology outpatient department with proximal myopathy as the presenting feature of PHP along with a hypercalcemic crisis. Her serum calcium and intact parathyroid hormone levels were very high. Her symptoms and calcium levels improved with adequate hydration and bisphosphonate therapy. Ultrasonography of the thyroid and parathyroid glands and Tc99m sestamibi single-photon emission computed tomography-computed tomography of the parathyroid glands suggested adenoma or carcinoma of the parathyroid gland on the right side with another irregular right-sided thyroid nodule. Electromyography showed low-amplitude polyphasic potentials suggestive of myopathy. Subsequently, the patient underwent surgical resection of both the right parathyroid glands and the thyroid nodule. Histopathology report was suggestive of parathyroid adenoma and papillary thyroid carcinoma. Hypercalcemic crisis is a rare clinical scenario, which needs prompt diagnosis and treatment. Otherwise, the condition may have a fatal outcome. Due to its diverse presentation, physicians should be aware of this condition. Moreover, we need to be cautious in treating a patient having hyperparathyroidism with thyroid nodule due to possible concomitant thyroid malignancy.

Myotoxicity Induced by Antiepileptic Drugs: Could be a Rare but Serious Adverse Event?

Antiepileptic drugs (AEDs) are used in various pathologies such as including epilepsy, migraine, neuropathic pain, etc. They can improve symptoms but cause adverse events (ADRs). Case reports have reported that one rare but serious AED-induced adverse reaction that has appeared in case reports is myotoxicity from rhabdomyolysis. Rhabdomyolysis can be induced by a therapeutically dosed occur with therapeutic doses of antiepileptic drugs and is in most cases reversible, although rarely it can cause serious complications. Clinical manifestations of rhabdomyolysis range from a single isolated asymptomatic rise in serum CK levels to severe electrolyte imbalances, cardiac arrhythmia, acute and disseminated renal failure, intravascular coagulation, and other symptoms. Many clinical cases reported that both conventional older and newer AEDs, as well as propofol, can cause rhabdomyolysis, even if there are no conclusive data. It has recently been shown that genetic factors certainly contribute to adverse reactions of antiepileptic drugs. A study of genetic polymorphism in patients with AED-induced rhabdomyolysis may be useful to explain the rarity of this adverse event and to improve the treatment of these AED patients, in terms of AED type and dose adjustment.

Recommendations for lipid modification in patients with ischemic stroke or transient ischemic attack: A clinical guide by the Hellenic Stroke Organization and the Hellenic Atherosclerosis Society

This document presents the consensus recommendations of the Hellenic Stroke Organization and the Hellenic Atherosclerosis Society for lipid modification in patients with ischemic stroke or transient ischemic attack. This clinical guide summarizes the current literature on lipid management and can be of assistance to the physicians treating stroke patients in clinical practice.

Carbimazole induced rhabdomyolysis

SUMMARY

Carbimazole is a commonly used antithyroid drug (ATD), which is associated with several well-established side effects. However, Carbimazole-induced rhabdomyolysis is rarely reported in the literature. We report a 27-year-old male who presented with upper limb myalgia and significantly raised creatine kinase elevation, 1-month post commencement of Carbimazole for Graves' disease. Carbimazole was ceased with subsequent clinical and biochemical improvement. Though the pathophysiology remains unclear, we hope to raise awareness regarding this rare adverse effect with a view to promote early recognition and prompt discontinuation of the offending medication caused by a commonly used medication in endocrinology.

LEARNING POINTS

Musculoskeletal complaints can relate to unidentified and untreated hyperthyroidism. However one must be mindful that the treatment for these disorders can too induce myopathies. ATD-induced myopathy should be considered when there is a temporal relationship between introduction of ATDs and the onset of symptoms. If ATD-induced myopathy is being considered, other causes of myopathy should still be outruled. Prompt discontinuation of potentially offending medications may provide resolution of symptoms and avoid significant consequences.

Skeletal Muscle and Childhood Cancer: Where are we now and where we go from here

Skeletal muscle (muscle) is essential for physical health and for metabolic integrity, with sarcopenia (progressive muscle mass loss and weakness), a pre-curser of aging and chronic disease. Loss of lean mass and muscle quality (force generation per unit of muscle) in the general population are associated with fatigue, weakness, and slowed walking speed, eventually interfering with the ability to maintain physical independence, and impacting participation in social roles and quality of life. Muscle mass and strength impairments are also documented during childhood cancer treatment, which often persist into adult survivorship, and contribute to an aging phenotype in this vulnerable population. Although several treatment exposures appear to confer increased risk for loss of mass and strength that persists after therapy, the pathophysiology responsible for poor muscle quantity and quality is not well understood in the childhood cancer survivor population. This is partly due to limited access to both pediatric and adult survivor muscle tissue samples, and to difficulties surrounding non-invasive investigative approaches for muscle assessment. Because muscle accounts for just under half of the body's mass, and is essential for movement, metabolism and metabolic health, understanding mechanisms of injury responsible for both initial and persistent dysfunction is important, and will provide a foundation for intervention. The purpose of this review is to provide an overview of the available evidence describing associations between childhood cancer, its treatment, and muscle outcomes, identifying gaps in current knowledge.

Effect of vitamin E and alpha lipoic acid on intestinal development associated with wooden breast myopathy in broilers

Intestinal development is closely associated with inflammatory wooden breast (WB) myopathy. Vitamin E (VE) and alpha lipoic acid (ALA) with antioxidant and anti-inflammatory effects were used independently and in combination to evaluate their effects on intestinal developmental changes in ileal morphology and expression of genes related with gut nutrient transport, structure, and inflammation in broilers during the first 3 wk posthatch. A total of 160 newly hatched Ross 708 broiler chicks were randomly assigned into a control and 3 dietary treatments with 10 replicates of 4 birds each. Supplementation of VE (160 mg/kg) and ALA (500 mg/kg) independently and in combination were fed during the first 3 wk. At 1, 2, and 3 wk of age, one chick from each pen was harvested. Plasma VE concentration and ileal morphology were determined. Gene expression was measured by real-time quantitative PCR. Broilers in VE and combination of ALA and VE group had higher plasma VE concentration than the control and ALA group at 1, 2, and 3 wk of age (P < 0.01). All dietary treatments increased ileal villus height at 1 wk of age (P < 0.01) and decreased intraepithelial lymphocytes at 3 wk of age compared to the control (P ≤ 0.05). Combination of VE and ALA increased collagen type IV alpha 1 chain expression (P ≤ 0.05) and improved basement membrane structure indicating increased gut basement membrane integrity at 2 and 3 wk of age compared to the control. Expression of lipopolysaccharide-induced tumor necrosis factor-alpha factor associated with inflammation was decreased in all dietary treatments at 3 wk of age compared to the control (P < 0.01). Ileal morphology and gene expression were closely correlated with breast muscle morphology and gene expression. These results suggest that VE and ALA especially when they were combined in the diet had positive effects on mitigating intestinal inflammation and improving nutrient transport beginning at 1 wk of age, which is likely critical in reducing the severity of WB.

Cross-Talk Between Extracellular Matrix and Skeletal Muscle: Implications for Myopathies

Skeletal muscle (SM) comprises around 40% of total body weight and is among the most important plastic tissues, as it supports skeletal development, controls body temperature, and manages glucose levels. Extracellular matrix (ECM) maintains the integrity of SM, enables biochemical signaling, provides structural support, and plays a vital role during myogenesis. Several human diseases are coupled with dysfunctions of the ECM, and several ECM components are involved in disease pathologies that affect almost all organ systems. Thus, mutations in ECM genes that encode proteins and their transmembrane receptors can result in diverse SM diseases, a large proportion of which are types of fibrosis and muscular dystrophy. In this review, we present major ECM components of SMs related to muscle-associated diseases, and discuss two major ECM myopathies, namely, collagen myopathy and laminin myopathies, and their therapeutic managements. A comprehensive understanding of the mechanisms underlying these ECM-related myopathies would undoubtedly aid the discovery of novel treatments for these devastating diseases.

Semi-automated volumetry of MRI serves as a biomarker in neuromuscular patients

BACKGROUND

Muscle MRI is of increasing importance for neuromuscular patients to detect changes in muscle volume, fat-infiltration, and edema. We developed a method for semi-automated segmentation of muscle MRI datasets.

METHODS

An active contour-evolution algorithm implemented within the ITK-SNAP software was used to segment T1-weighted MRI, and to quantify muscle volumes of neuromuscular patients (n = 65).

RESULTS

Semi-automated compared with manual segmentation was shown to be accurate and time-efficient. Muscle volumes and ratios of thigh/lower leg volume were lower in myopathy patients than in controls (P < .0001; P < .05). We found a decrease of lower leg muscle volume in neuropathy patients compared with controls (P < .01), which correlated with clinical parameters. In myopathy patients, muscle volume showed a positive correlation with muscle strength (r_left = 0.79, p_left  < .0001). Muscle volumes were independent of body mass index and age.

CONCLUSIONS

Our method allows for exact and time-efficient quantification of muscle volumes with possible use as a biomarker in neuromuscular patients.

Muscle Toxicity of Drugs: When Drugs Turn Physiology into Pathophysiology

Drugs are prescribed to manage or prevent symptoms and diseases, but may sometimes cause unexpected toxicity to muscles. The symptomatology and clinical manifestations of the myotoxic reaction can vary significantly between drugs and between patients on the same drug. This poses a challenge on how to recognize and prevent the occurrence of drug-induced muscle toxicity. The key to appropriate management of myotoxicity is prompt recognition that symptoms of patients may be drug related and to be aware that inter-individual differences in susceptibility to drug-induced toxicity exist. The most prevalent and well-documented drug class with unintended myotoxicity are the statins, but even today new classes of drugs with unintended myotoxicity are being discovered. This review will start off by explaining the principles of drug-induced myotoxicity and the different terminologies used to distinguish between grades of toxicity. The main part of the review will focus on the most important pathogenic mechanisms by which drugs can cause muscle toxicity, which will be exemplified by drugs with high risk of muscle toxicity. This will be done by providing information on key clinical and laboratory aspects, muscle electromyography patterns and biopsy results, and pathological mechanism and management for a specific drug from each pathogenic classification. In addition, rather new classes of drugs with unintended myotoxicity will be highlighted. Furthermore, we will explain why it is so difficult to diagnose drug-induced myotoxicity, and which tests can be used as a diagnostic aid. Lastly, a brief description will be given of how to manage and treat drug-induced myotoxicity.

Adiponectin in Myopathies

In skeletal muscle, adiponectin has varied and pleiotropic functions, ranging from metabolic, anti-inflammatory, insulin-sensitizing to regenerative roles. Despite the important functions exerted by adiponectin, the study of the hormone in myopathies is still marginal. Myopathies include inherited and non-inherited/acquired neuromuscular pathologies characterized by muscular degeneration and weakness. This review reports current knowledge about adiponectin in myopathies, regarding in particular the role of adiponectin in some hereditary myopathies (as Duchenne muscular dystrophy) and non-inherited/acquired myopathies (such as idiopathic inflammatory myopathies and fibromyalgia). These studies show that some myopathies are characterized by decreased concentration of plasma adiponectin and that hormone replenishment induces beneficial effects in the diseased muscles. Overall, these findings suggest that adiponectin could constitute a future new therapeutic approach for the improvement of the abnormalities caused by myopathies.

Drug-induced paraspinal myositis mimicking acute bilateral sciatica

Although cocaine induced myopathy and myotoxicity are described in the literature, we report a rare case of cocaine induced paraspinal myositis presenting with acute sciatic symptoms. A 35-year-old man presented with acute left-sided sciatica and was discharged from the emergency department (ED). He subsequently attended ED the following day in severe pain and bilateral sciatic symptoms, but denied symptoms of neurogenic bowel/bladder disturbance. Clinical examination was limited by severe pain: focal midline lumbar tenderness was elicited on palpation, per rectal and limb examinations were within normal limits with no significant neurological deficit. He was admitted for observation and pain management. His blood tests revealed a leucocyte count of 21.5×10⁹/L, C reactive protein of 89 mg/L and deranged renal function with creatinine of 293 μmol/L. An urgent lumbar spine MRI was arranged to rule out a discitis or epidural abscess. Lumbar MRI did not demonstrate any features of discitis but non-specific appearances of paraspinal inflammation raised the suspicion of a paraspinal myositis. Creatinekinase (CK) was found to be 66329 IU/L and a detailed history revealed he was a cocaine user. Paraspinal muscle biopsy confirmed histological features compatible with myositis. Other serological tests were negative, including anti-GBM, ANCA, ANA, Rheumatoid factor, Hep B, Hep C, myositis specific ENA, Treponema pallidum, Borrelia burgdorferi, Rickettsia, Leptospira, EBV and CMV. There was good clinical response to treatment with prednisolone 20 mg OD with an improvement in renal function, CK levels and CRP. He had resumed normal activities and return to work at 6-week follow-up. A detailed social history including substance misuse is important in patients presenting to the ED-especially in cases of severe musculoskeletal pain with no obvious localising features. Drug induced myotoxicity, although rare, can result in symptomatic patients with severe renal failure.

Foot Kinetic and Kinematic Profile in Type 2 Diabetes Mellitus with Peripheral Neuropathy A Hospital-Based Study from South India

BACKGROUND

A kinetic change in the foot such as altered plantar pressure is the most common etiological risk factor for foot ulcers in people with diabetes mellitus. Kinematic alterations in joint angle and spatiotemporal parameters of gait have also been frequently observed in participants with diabetic peripheral neuropathy (DPN). Diabetic peripheral neuropathy leads to various microvascular and macrovascular complications of the foot in type 2 diabetes mellitus. There is a gap in the literature for biomechanical evaluation and assessment of type 2 diabetes mellitus with DPN in the Indian population. We sought to assess and determine the biomechanical changes, including kinetics and kinematics, of the foot in DPN.

METHODS

This cross-sectional study was conducted at a diabetic foot clinic in India. Using the purposive sampling method, 120 participants with type 2 diabetes mellitus and DPN were recruited. Participants with active ulceration or amputation were excluded.

RESULTS

The mean ± SD age, height, weight, body mass index, and diabetes duration were 57 ± 14 years, 164 ± 11 cm, 61 ± 18 kg, 24 ± 3 kg/m², and 12 ± 7 years, respectively. There were significant changes in the overall biomechanical profile and clinical manifestations of DPN. The regression analysis showed statistical significance for dynamic maximum plantar pressure at the forefoot with age, weight, height, diabetes duration, body mass index, knee and ankle joint angle at toe-off, pinprick sensation, and ankle reflex ( R = 0.71, R² = 0.55, F_12,108 = 521.9 kPa; P = .002).

CONCLUSIONS

People with type 2 diabetes mellitus and DPN have significant changes in their foot kinetic and kinematic parameters. Therefore, they could be at higher risk for foot ulceration, with underlying neuropathy and biomechanically associated problems.

Juvenile Idiopathic Inflammatory Myopathies

The juvenile idiopathic inflammatory myopathies (JIIM) are a group of rare, chronic, autoimmune illnesses that affect muscle and, to a lesser extent, skin. The presence of new-onset weakness and, in juvenile dermatomyositis, typical rahes, should lead to consideration of these diagnoses. Careful evaluation to exclude alternative diagnoses is needed. Investigations include a variety of blood tests, imaging, and possibly muscle biopsy. Validated clinical assessments are available for monitoring. Standard treatment includes corticosteroids and methotrexate and often extends beyond 1 year. Outcomes are generally good, but disease persistence remains problematic. Early involvement of providers with expertise in JIIM is essential.

Sarcocystis myopathy in a patient with HIV-AIDS

Sarcocystosis is a zoonotic infection that causes intestinal and muscular illnesses in humans. Sarcocystosis was until recently considered rare in humans. To complete their life cycle, Sarcocystis species require both a definitive and an intermediate host. Humans are the definitive host when infected by one of two species: Sarcocystis hominis (from eating undercooked beef) or Sarcocystis suihominis (from eating uncooked pork). Infection with either of these species results in intestinal sarcocystosis, causing a self-limited disease characterized by nausea, abdominal pain, and diarrhea. Humans act as the intermediate host when infected by Sarcocystis nesbitti, resulting in the markedly different clinical picture of muscular sarcocystosis. Most documented cases of muscular sarcocystosis were assumed to be acquired in Malaysia, in addition to other regions of Southeast Asia and India. Published cases of muscular sarcocystosis from the Middle East, Central and South America, and Africa are all rare. Although the clinical presentation of muscular sarcocystosis remains to be fully characterized, fever, myalgia, and headache are among the most common symptoms. Here, we report a patient from sub-Saharan Africa with chronic Sarcocystis myopathy and well-controlled HIV-AIDS.

Next-Generation Sequencing to Diagnose Muscular Dystrophy, Rhabdomyolysis, and HyperCKemia

Background:Neuromuscular disorders are a phenotypically and genotypically diverse group of diseases that can be difficult to diagnose accurately because of overlapping clinical features and nonspecific muscle pathology. Next-generation sequencing (NGS) is a high-throughput technology that can be used as a more time- and cost-effective tool for identifying molecular diagnoses for complex genetic conditions, such as neuromuscular disorders.Methods:One hundred and sixty-nine patients referred to a Canadian neuromuscular clinic for evaluation of possible muscle disease were screened with an NGS panel of muscular dystrophy–associated genes. Patients were categorized by the reason of referral (1) muscle weakness (n=135), (2) recurrent episodes of rhabdomyolysis (n=18), or (3) idiopathic hyperCKemia (n=16).Results:Pathogenic and likely pathogenic variants were identified in 36.09% of patients (61/169). The detection rate was 37.04% (50/135) in patients with muscle weakness, 33.33% (6/18) with rhabdomyolysis, and 31.25% (5/16) in those with idiopathic hyperCKemia.Conclusions:This study shows that NGS can be a useful tool in the molecular workup of patients seen in a neuromuscular clinic. Evaluating the utility of large panels of a muscle disease-specific NGS panel to investigate the genetic susceptibilities of rhabdomyolysis and/or idiopathic hyperCKemia is a relatively new field. Twenty-eight of the pathogenic and likely pathogenic variants reported here are novel and have not previously been associated with disease.

Pitting Oedema in a Patient with Lumbar Disc Herniation: Case report of an unusual association

Oedema refers to the excessive accumulation of fluid within intercellular tissues as a result of disequilibrium between the capillary hydrostatic and oncotic pressure gradients. Lumbar disc herniation (LDH) commonly causes lower back pain and radicular leg pain. We report a 57-year-old female who presented to the neurosurgery clinic of the Bam University of Medical Sciences, Bam, Iran, in 2015 with pain and pitting oedema in the bilateral lower extremities. Magnetic resonance imaging confirmed a diagnosis of LDH of the L3-L4 and L4-L5 vertebrae. The patient subsequently underwent a bilateral laminotomy and foraminotomy of the involved vertebrae to relieve her pain. Following the surgery, there was a complete resolution of the LDH-related symptoms as well as the oedema. Although LDH has never before been associated with oedema, it may nevertheless cause lower limb oedema in exceptional and rare cases, as highlighted in this patient.

Overexpression of miRNA-9 Generates Muscle Hypercontraction Through Translational Repression of Troponin-T in Drosophila melanogaster Indirect Flight Muscles

MicroRNAs (miRNAs) are small noncoding endogenous RNAs, typically 21-23 nucleotides long, that regulate gene expression, usually post-transcriptionally, by binding to the 3'-UTR of target mRNA, thus blocking translation. The expression of several miRNAs is significantly altered during cardiac hypertrophy, myocardial ischemia, fibrosis, heart failure, and other cardiac myopathies. Recent studies have implicated miRNA-9 (miR-9) in myocardial hypertrophy. However, a detailed mechanism remains obscure. In this study, we have addressed the roles of miR-9 in muscle development and function using a genetically tractable model system, the indirect flight muscles (IFMs) of Drosophila melanogaster Bioinformatics analysis identified 135 potential miR-9a targets, of which 27 genes were associated with Drosophila muscle development. Troponin-T (TnT) was identified as major structural gene target of miR-9a. We show that flies overexpressing miR-9a in the IFMs have abnormal wing position and are flightless. These flies also exhibit a loss of muscle integrity and sarcomeric organization causing an abnormal muscle condition known as "hypercontraction." Additionally, miR-9a overexpression resulted in the reduction of TnT protein levels while transcript levels were unaffected. Furthermore, muscle abnormalities associated with miR-9a overexpression were completely rescued by overexpression of TnT transgenes which lacked the miR-9a binding site. These findings indicate that miR-9a interacts with the 3'-UTR of the TnT mRNA and downregulates the TnT protein levels by translational repression. The reduction in TnT levels leads to a cooperative downregulation of other thin filament structural proteins. Our findings have implications for understanding the cellular pathophysiology of cardiomyopathies associated with miR-9 overexpression.

A study of acute muscle dysfunction with particular reference to dengue myopathy

Background:

Acute myopathy is a common cause of acute motor quadriparesis which has various etiologies with different courses of illness and prognosis depending on the cause. Understanding this diversity helps us in proper approach toward diagnosis, predicting the prognosis, and possible complications and in improving the treatments that are being provided. This study was planned to study the clinical, electrophysiological, and etiological profile of patients presenting with acute myopathy. We also studied how dengue-related acute myopathy differs from other causes and also difference between myopathy due to myositis and hypokalemia in cases of dengue.

Materials and Methods:

This was a prospective, observational study involving all clinically suspected cases of acute myopathy of not more than 4 weeks duration with raised serum creatine kinase (CK) level. They were subjected to detailed clinical evaluation along with hematological, biochemical, microbiological, and electrophysiological studies and followed-up for outcome at 1 and 3 months. Muscle biopsy and histopathological examination were done in selected patients after taking informed consent. Statistical analysis was performed by appropriate methods using SPSS version 16.0 (Chicago, IL, USA).

Results:

We evaluated thirty patients of acute myopathy with raised CK level. Seventeen patients had fever, 11 had myalgia, and 5 had skin lesions. All presented with symmetric weakness, 17 (56.7%) patients having predominantly proximal weakness, neck or truncal weakness in 6 (20%), hyporeflexia in 12 (40%), with mean Medical Research Council (MRC) sum score of 46.67 ± 6.0. Eight (mean modified Barthel index [MBI] at presentation - 15 ± 3.7) patients had poor functional status according to MBI and 15 according to modified Rankin scale (MRS) (mean MRS score - 2.5 ± 1.2). Etiology was dengue viral infection in 14 patients; hypokalemia due to various causes other than dengue in 8; pyomyositis in 3; dermatomyositis, polymyositis, thyrotoxicosis, systemic lupus erythematosus, and unknown etiology in one each. Only eight patients had abnormal electrophysiology and seven among nine biopsies done were abnormal. At 1 month, 24 (80.0%) and 23 (76.7%) patients had achieved normal MBI and MRS scores with 28 (93.3) and 27 (90%) patients, respectively, at 3 months. Dengue with hypokalemia had less myalgia, more of hyporeflexia, and lower serum CK compared to those without hypokalemia.

Conclusion:

Dengue infection and hypokalemia due to various causes are the most common causes of acute myopathy and are associated with rapid and complete recovery within 1 month. Shorter duration of illness, higher MRC sum score, better disability status at presentation, lower serum CK correlate with better outcome. Biopsy was decisive in <20% cases; hence, it is not primary investigation in acute myopathy.

The role of ultrasound-guided fine needle aspiration biopsy in musculoskeletal diseases

Ultrasonography (US) is a readily available non-invasive tool useful for the detection of musculoskeletal and soft tissue masses. Although X-Ray is often the first imaging study for evaluating both bone and soft tissue lesions, and magnetic resonance imaging and computed tomography are mandatory in lesions staging, US is increasingly used for the early assessment of musculoskeletal and soft-tissue masses and for guiding procedures and biopsies. Surgical biopsy or fine needle aspiration biopsy (FNAB) is needed to ascertain the nature of any lesion. FNAB is a low cost technique, safer and less traumatic than an open surgical biopsy. Significant complications are rare, mostly related to the site of biopsy. Knowledge of indications, limitations, anatomical and pathological access, adequate technical expertise in US imaging and in intervention skills are the critical factors of the appropriate and safe use of FNAB. By now, the role of FNAB in musculoskeletal diseases is controversial and there is still a heated debate in the scientific community.

The investigation and management of metabolic myopathies

Metabolic myopathies (MM) are rare inherited primary muscle disorders that are mainly due to abnormalities of muscle energy metabolism resulting in skeletal muscle dysfunction. These diseases include disorders of fatty acid oxidation, glyco(geno)lytic muscle disorders and mitochondrial respiratory chain (MRC) disease. Clinically these disorders present with a range of symptoms including infantile hypotonia, myalgia/exercise tolerance, chronic or acute muscle weakness, cramps/spasms/stiffness or episodic acute rhabdomyolysis. The precipitant may be fasting, infection, general anaesthesia, heat/cold or most commonly, exercise. However, the differential diagnosis includes a wide range of both acquired and inherited conditions and these include exposure to drugs/toxins, inflammatory myopathies, dystrophies and channelopathies. Streamlining of existing diagnostic protocols has now become a realistic prospect given the availability of second-generation sequencing. A diagnostic pathway using a ‘rhabdomyolysis’ gene panel at an early stage of the diagnostic process is proposed. Following detailed clinical evaluation and first-line investigations, some patients will be identified as candidates for McArdle disease/glycogen storage disease type V or MRC disease and these will be referred directly to the specialised services. However, for the majority of patients, second-line investigation is best undertaken through next-generation sequencing using a ‘rhabdomyolysis’ gene panel. Following molecular analysis and careful evaluation of the findings, some patients will receive a clear diagnosis. Further functional or specific targeted testing may be required in other patients to evaluate the significance of uncertain/equivocal findings. For patients with no clear diagnosis, further investigations will be required through a specialist centre.

Muscle disorders: the latest investigations

Patients with muscle disorders can present a diagnostic challenge to physicians because of the different ways they can present and the large number of different underlying causes. Recognition of the 'myopathic phenotype' coupled with investigations usually including electrodiagnostic and histological investigations have been essential for diagnosing the underlying cause of a myopathy. Despite these standard investigations, some patients can remain undiagnosed. New tests including more specific antibody tests for immune-mediated myopathies and the introduction of next-generation sequencing promise to revolutionise diagnostic approaches for immune and inherited myopathies, but clinical expertise remains essential to choose the most appropriate tests and interpret the results. The aim of this review is to provide an overview of the different presentations to the neuromuscular clinic and the latest investigations that can be helpful in the diagnosis of muscle disorders.

Novel excitation-contraction coupling related genes reveal aspects of muscle weakness beyond atrophy-new hopes for treatment of musculoskeletal diseases

Research over the last decade strengthened the understanding that skeletal muscles are not only the major tissue in the body from a volume point of view but also function as a master regulator contributing to optimal organismal health. These new contributions to the available body of knowledge triggered great interest in the roles of skeletal muscle beyond contraction. The World Health Organization, through its Global Burden of Disease (GBD) report, recently raised further awareness about the key importance of skeletal muscles as the GDB reported musculoskeletal (MSK) diseases have become the second greatest cause of disability, with more than 1.7 billion people in the globe affected by a diversity of MSK conditions. Besides their role in MSK disorders, skeletal muscles are also seen as principal metabolic organs with essential contributions to metabolic disorders, especially those linked to physical inactivity. In this review, we have focused on the unique function of new genes/proteins (i.e., MTMR14, MG29, sarcalumenin, KLF15) that during the last few years have helped provide novel insights about muscle function in health and disease, muscle fatigue, muscle metabolism, and muscle aging. Next, we provide an in depth discussion of how these genes/proteins converge into a common function of acting as regulators of intracellular calcium homeostasis. A clear link between dysfunctional calcium homeostasis is established and the special role of store-operated calcium entry is analyzed. The new knowledge that has been generated by the understanding of the roles of previously unknown modulatory genes of the skeletal muscle excitation-contraction coupling (ECC) process brings exciting new possibilities for treatment of MSK diseases, muscle regeneration, and skeletal muscle tissue engineering. The next decade of skeletal muscle and MSK research is bound to bring to fruition applied knowledge that will hopefully offset the current heavy and sad burden of MSK diseases on the planet.

Polymyositis as presenting manifestation of gallbladder carcinoma: A case report

INTRODUCTION

Inflammatory myositis as a paraneoplastic presentation of gallbladder cancer is an extremely rare event. In this paper we reported the first case of gallbladder carcinoma presented as polymyositis.

PRESENTATION OF CASE

A 68-year-old housewife presented with proximal muscles weakness, pain, significant decrease in force of proximal muscles, and globally decreased deep tendon reflexes. Laboratory studies revealed an anemia, increased acute phase reactants and increased serum creatine phosphokinase (CPK) levels. Electromyography (EMG) and nerve conduction velocity test (NCV) demonstrated mild myopathic changes. Muscle biopsy was suggestive for polymyositis. Corticosteroid therapy initiated and a meticulous search for probable underlying malignancy performed concurrently. Malignancy workup finally revealed a gallbladder tumor. Patient candidated for extended cholecystectomy. Pathologic evaluation of gallbladder tumor demonstrated a moderately differentiated carcinoma. Progressive improvement in clinical conditions and complete normalization of laboratory parameters occurred post-operatively. After 8 months of follow-up patient is still alive and in good state of health. There is no evidence of metastatic or local recurrence of tumor. Musculoskeletal complaints subsided completely.

DISCUSSION

Gallbladder carcinoma is a rare and usually aggressive malignancy. Its primary presentation by paraneoplastic syndromes especially in the form of paraneoplastic neurological syndromes is an extremely rare event. Some believes that increased association between inflammatory myopathy and malignancy is limited to the dermatomyositis; however, presentation of our patient as polymyositis is contrary to this. This is the first reported case of gallbladder cancer who presented with polymyositis.

CONCLUSION

Gallbladder cancer though rare, should be considered in patients with inflammatory myositis.