Bilateral leg pain and unilateral calf atrophy caused by polymyositis accompanying lumbar spinal stenosis and disc herniation: a case report

Polymyositis is a subgroup of idiopathic inflammatory myopathies characterized by symmetric proximal limb weakness and chronic skeletal muscle inflammation. We herein report the first case of bilateral leg pain and unilateral calf atrophy caused by polymyositis accompanying lumbar spinal stenosis and disc herniation. A 52-year-old man presented with intermittent claudication and calf pain that had become gradually aggravated during the last 3 months. Magnetic resonance imaging showed spinal stenosis at the L3/4 and L4/5 levels and lumbar disc herniation at the L4/5 level. Preoperative laboratory investigations revealed elevated muscle enzyme concentrations. Magnetic resonance imaging also showed atrophy, fatty degeneration, and edema in both calf muscles. Histological examination showed inflammatory myositis and fibrosis in the perifascicular connective tissues. The patient was diagnosed with polymyositis. We performed decompressive laminectomy at the L3/4 and L4/5 levels and discectomy at the L4/5 level. After administration of prednisolone for 6 months and methotrexate for 3 months, the patient’s bilateral calf pain and abnormal laboratory findings improved. The combination of surgical decompression and adequate medical treatment resulted in a successful recovery. Polymyositis should be suspected in patients with lumbar spinal stenosis or lumbar disc herniation who exhibit increased muscle enzyme concentrations or lower extremity muscle atrophy.

Deep venous thrombosis in an individual with statin-exposed anti-SRP myopathy: case report and review of literature

Background Immune-mediated necrotizing myopathy (IMNM) is characterized by proximal muscle weakness, elvated serum muscle enzyme levels, myopathic electromyography findings, and necrotic muscle fiber with few inflammatory cell infiltration in muscle biopsies. Statins, the first line drug to lower triglyceride and cholesterol level in blood, have been reported to be associated with statins-induced necrotizing autoimmune myopathy (SINAM). Although anti-3-hydroxy-3-methylglutarylcoenzyme-A reductase (anti-HMGCR) myopathy is considered as the leading myopathy related to the statins medication, anti-signal recognition particle (SRP) myopathy were also identified in several cases with statin exposure. The risk of deep venous thrombosis (DVT) is substantially high in individuals with autoimmune inflammatory diseases. But few studies have reported the occurrence and recommendation for treatment of DVT in patients with anti-SRP myopathy. Here, we reported a statin-exposed anti-SRP myopathy individual developed DVT who was successfully treated with catheter-directed thrombolysis (CDT) and systemic anticoagulants therapy. Case presentation A 56-year-old Chinese female came to the outpatient room with gradually progressive bilateral lower-extremity weakness. Magnetic resonance imaging revealed myopathy in bilateral thighs. Serum anti-SRP antibody was positive. She was diagnosed with anti-SRP myopathy. When treated with corticosteroids and immunosuppressants, the patient developed mild edema and pain of left lower extremity. Angiography and ultrasound revealed diffuse venous thrombosis of left lower extremity. Therapy was initiated with CDT and lower molecular weight heparin, then switched to once daily oral rivaroxaban. Meanwhile, steroids combined with tacrolimus were also carried on while simvastatin was discontinued. One month later, patient’s symptoms were resolved and only partial thrombosis in left femoral vein was remained. Conclusion The prevalence of DVT in patient with anti-SRP myopathy was rare. No well-established treatment strategy is available to manage the IMNM and DVT at the same time. The systemic anticoagulants therapy combined CDT can be an effective therapeutic approach to address extensive DVT in patient with anti-SRP myopathy.

Glucose intolerance in aging is mediated by the Gpcpd1-GPC metabolic axis

Skeletal muscle plays a central role in the regulation of systemic metabolism during lifespan. With aging, muscle mediated metabolic homeostasis is perturbed, contributing to the onset of multiple chronic diseases. Our knowledge on the mechanisms responsible for this age-related perturbation is limited, as it is difficult to distinguish between correlation and causality of molecular changes in muscle aging. Glycerophosphocholine phosphodiesterase 1 (GPCPD1) is a highly abundant muscle enzyme responsible for the hydrolysis of the lipid glycerophosphocholine (GPC). The physiological function of GPCPD1 remained largely unknown. Here, we report that the GPCPD1-GPC metabolic pathway is dramatically perturbed in the aged muscle. Muscle-specific inactivation of Gpcpd1 resulted in severely affected glucose metabolism, without affecting muscle development. This pathology was muscle specific and did not occur in white fat-, brown fat- and liver-specific Gpcpd1 deficient mice. Moreover, in the muscle specific mutant mice, glucose intolerance was markedly accelerated under high sugar and high fat diet. Mechanistically, Gpcpd1 deficiency results in accumulation of GPC, without any other significant changes in the global lipidome. This causes an aged-like transcriptomic signature in young Gpcpd1 deficient muscles, changes in myofiber osmolarity, and impaired insulin signaling. Finally, we report that GPC levels are markedly perturbed in muscles from both aged humans and patients with Type 2 diabetes. These results identify the GPCPD1-GPC metabolic pathway as critical to muscle aging and age-associated glucose intolerance.

Relationship Between Physical Activity Level and Muscle Markers in a Population-Based Sample of Children and Adolescents

Objectives: The study aimed was to investigate the relationship between physical activity (PA) levels and muscle markers in healthy children and adolescents. Methods: This cross-sectional study was conducted in 2020 among school students from Isfahan, Iran. Using cluster sampling, 159 students aged 7 to 18 years were selected. In addition to the physical examination, the PA level was assessed using a valid questionnaire. The serum levels of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), and alanine aminotransferase (ALT) were measured. Statistical analysis was performed using the Pearson correlation test. Results: The samples included 79 girls and 80 boys with a mean age (standard deviation) of 12.72 (3.06) years and a mean body mass index of 18.30 (3.70) kg/m2. The mean AST and CPK were significantly higher in boys than in girls (P < 0.05). Participants with higher PA levels had significantly lower LDH and ALT than other participants (-0.20, P = 0.003, and 0.044 P = 0.295, respectively). There was no significant relationship between PA level and muscle enzyme levels. Conclusions: The findings of this study indicated that higher PA level was associated with lower serum muscle markers other than LDH. This suggests that the best types of PA for children and adolescents are those activities with rest sets to prevent muscle damage.

Successful treatment of tuberculosis combined with drug-induced myopathy using corticosteroid therapy: a case report

A 39-year-old woman was admitted to our hospital on 19 January 2019 because of a 10-day history of intolerance to oils in her food, fatigue, and yellowing of the skin and sclera. In December 2018, the patient had been diagnosed with tuberculous pleurisy at a local hospital and received quadruple anti-tuberculosis treatment. Ten days before presentation to our hospital, she had developed anorexia, fatigue, nausea, loss of appetite, cough, and shortness of breath. She visited a local hospital, where she was considered to have drug-induced hepatitis. She discontinued the anti-tuberculosis drugs and liver protection treatment. After 3 days, her symptoms had not substantially improved. She visited the infection department of our hospital for further diagnosis and treatment. After 6 days of treatment, the patient’s symptoms were not significantly improved, her liver and muscle enzyme concentrations were further increased, and her limbs had become weaker and more difficult to move. We considered diagnoses of drug-induced hepatitis and drug-induced myopathy. The patient was treated with intravenous methylprednisolone at 40 mg once a day for 16 days and other symptomatic treatments. Her symptoms significantly improved and she was discharged.

Case Report: The Neuromusclar Triad of Immune Checkpoint Inhibitors: A Case Report of Myositis, Myocarditis, and Myasthenia Gravis Overlap Following Toripalimab Treatment

The neuromuscular adverse events of immune checkpoint inhibitor (ICI) treatment include myositis, polymyalgia rheumatica, myocarditis, and myasthenia syndrome. We report a 47-year old female presenting with external ophthalmoplegia, generalized muscle weakness, and third-degree atrioventricular block 4 weeks after toripalimab treatment for metastatic thymoma. Creatine kinase was elevated to 25,200 U/l and cardiac troponin I to 2.796 ng/ml. Autoantibody profiling shows positive anti-ryanodine receptor and anti-acetylcholine receptor antibodies and negative myositis specific antibodies. Repetitive nerve stimulation did not reveal decrement of compound muscle action potentials. Pulse methylprednisolone and immunoglobulin infusion, together with temporary pacemaker insertion normalized her muscle enzyme levels and cardiac rhythm. This is the first report of overlaping neuromuscular adverse event of toripalimab.

Severe onset of inflammatory myositis in a child: think to paraneoplastic myositis

Background Juvenile idiopathic inflammatory myopathies (JIIMs) are a group of heterogenous, acquired, autoimmune disorders that affect the muscle. While the association between IIMs and malignancy has been widely reported in adults, cancer-associated myositis (CAM) is rare in children, so that routine malignancy screening is not generally performed. This report shows a case of severe CAM in a child. Case presentation An 11-years-old girl presented with worsening dyspnea after a 3-weeks history of progressive proximal weakness, myalgia, dysphagia, and weight loss. Her past history was remarkable for a type I Arnold-Chiari malformation associated with an anterior sacral meningocele. Physical examination showed severe hypotony and hypotrophy. Pulse oximetry and blood test showed a type II respiratory failure (SpO2 88%, pCO2 68 mmHg) and increased muscle enzyme levels (CPK 8479 U/L, AST 715 U/L, ALT 383 U/L, LDH 1795 U/L). The patient needed invasive mechanical ventilation. Inflammatory myositis was considered and treatment with intravenous methylprednisolone (30 mg/Kg/day for 3 days followed by 2 mg/Kg/day) and IVIG (1 g/kg/day for 2 days) was started. Muscle biopsy showed endomysial and perimysial necrosis and inflammation. The presence of serum anti-TIF1-γ antibody positivity led to a malignancy screening. Whole-body MRI showed a mature teratoma underneath sacral meningocele and both lesions were surgically removed. Given the histological and clinical severity of the myopathy, mycophenolate (500 mg twice a day) and rituximab (360 mg/m2, 4 weekly infusions) were added. Due to extreme muscular wasting, severe malnutrition and intolerance to enteral feeding the patient needed a transient tracheostomy and parenteral nutrition, followed by physiotherapy, speech therapy and nocturnal non-invasive ventilation. A complete remission was achieved 3 months after. Conclusions Among cancer-associated autoantibodies (CAAs) in adult patients, anti-TIF1-γ carries the highest risk of CAM, which recognizes with a high likelihood a paraneoplastic pathogenesis. In children, anti-TIF1-γ antibody has been associated with severe cutaneous disease, lipodystrophy, and chronic disease course, but not with CAM, which is overall rare in younger patients. Severe onset of a JIIM, especially if anti-TIF1-γ antibody positive, should prompt suspect of a CAM and lead to a screening for malignancy.

A case of dermatomyositis in a patient with central core disease: unusual association with autoimmunity and genetic muscle disease

Background Dermatomyositis is an inflammatory muscle disease caused by immune-mediated muscle injury, and central core disease (CCD) is a congenital myopathy associated with disturbed intracellular calcium homeostasis and excitation-contraction coupling. To date, CCD has not been reported to have autoantibodies or coexist with inflammatory myopathy. Case presentation Here, we described the case of a 25-year-old woman who had progressive proximal muscle weakness, myalgia, pruritic macular rash, skin ulcers, and calcinosis. Dermatomyositis was initially suspected based on the clinical symptoms accompanied by elevated muscle enzyme levels, electromyography abnormalities, and a positive antinuclear antibody test. However, the patient’s muscle biopsy revealed the characteristic findings of both dermatomyositis and CCD, suggesting that dermatomyositis occurred in this patient with previously asymptomatic CCD. The patient did not have any pathogenic gene mutations associated with congenital myopathy, including RYR1 and SEPN1 in targeted next-generation sequencing. She received high-dose glucocorticoid therapy and azathioprine with a significant improvement in muscle strength. Conclusions We present a case of rare coexistence of dermatomyositis and CCD. Clinicians should be aware that patients with CCD may have inflammatory myopathy that responds well to immunosuppressive therapy.

MRI and muscle enzymes do not support the diagnosis of local anesthetic myotoxicity: a descriptive case series

BackgroundThe presence of thigh muscle edema as characterized by increased signal intensity on MRI has been used to support the diagnosis of presumed local anesthetic-induced myotoxicity reported after total knee arthroplasty (TKA) with continuous adductor canal block (CACB). However, neither postoperative baseline imaging appearance nor muscle enzyme values have been described in conjunction with this clinical scenario. Thus, the usefulness of MRI or enzymatic biomarkers of muscle injury for supporting the diagnosis of local anesthetic myotoxicity is unknown.MethodsThis descriptive case series documents postoperative MRI appearance of the ipsilateral upper leg, plus preoperative and postoperative creatine phosphokinase and aldolase values in volunteer patients who underwent uncomplicated TKA with CACB.ResultsIn 27 volunteer patients with no postsurgical evidence of clinically relevant myotoxicity, anterior thigh muscle edema was universally evident on imaging (n=12) and muscle enzyme values (n=19) were normal or only slightly elevated.ConclusionsThe non-specificity of these findings suggests that MRI and near normal muscle enzyme levels are of limited diagnostic value when there is clinical suspicion of local anesthetic myotoxicity in the setting of TKA with CACB.Trial registration numberNCT04821245.