A Case of Statin-Associated Autoimmune Myopathy: Management and Treatment.

Elevated lipid panels are associated with an increased risk of cardiovascular disease. Management of heart disease with lipid lowering agents play a vital role in medicine. Statins are one group of medications that are widely utilized in the medical field to decrease the risk of atherosclerotic disease. Statins work by inhibiting the hepatic enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR). Although statins are one of the most effective drugs for secondary and primary prevention of heart disease, they are not without risks and side effects such as hepatotoxicity and myopathy. We present a case of a male patient who developed progressively worsening muscle weakness and elevated muscle enzyme markers upon initiation of a statin. His symptoms persisted despite a trial of an alternative statin and subsequent discontinuation of all statin medications. A multitude of possible etiologies were considered and ranged from infectious, autoimmune, cancerous, to congenital in nature. Environmental factors, such as exposure to medications or toxins, were also considered as one of the possible precipitating factors. The association between his statin consumption and muscle weakness were not easily apparent at first. He required further workup including physical examination, electromyography, panel of myositis antibodies, and muscle biopsy. After clinical suspicion and elevated antibodies to HMGCR beyond the normal limit, he was discovered to have statin-associated autoimmune myopathy. The patient improved with the treatment of immunosuppressive agent's prednisone and methotrexate.

Progressive proximal muscle weakness with subacute onset in an elderly patient: a case report. / Debilidad muscular proximal progresiva de inicio subagudo en un paciente anciano: descripción de un caso.

INTRODUCTION: Statins are some of the most widely prescribed medications. Although statins are generally well tolerated, they can lead to musculoskeletal side effects. Statin-induced necrotizing autoimmune myositis (SINAM) is a rare condition and the prevalence is only 1 per 100,000 people. This disorder is characterized by progressive and severe symmetric muscle weakness, marked elevation of creatine kinase and persistent symptoms despite statin discontinuation. Electromyography commonly shows a nonspecific irritable myopathy pattern indistinguishable from other inflammatory myopathies. Muscle biopsy shows the presence of necrotic fibers, regenerating fibers without significant inflammatory cells and diffuse or focal upregulation of major histocompatibility complex class I expression. The anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) antibodies represent a characteristic serological feature of SINAM. CASE REPORT: We present a patient who developed progressive muscle weakness after taking simvastatin for the last seven years. At initial presentation, her creatine kinase level was 2,954 U/L and anti-HMGCR antibodies were positive. The biopsy showed a profound myopathic features with numerous necrotic fibers, some regenerating fibers and perimysial inflammatory cell infiltrate, combined with a diffuse overexpression of major histocompatibility complex class I products. She was diagnosed with SINAM, statin was suspended and a high dose of systemic corticosteroids, intravenous immunoglobulin therapy and methotrexate was started. At three-month follow-up, she had significant improvement in muscle strength and creatine kinase level returned to normal. CONCLUSION: In this case, exclusion of inflammatory myopathies, metabolic muscle disorders and other neurological diseases is necessary for establishing a reliable diagnosis. In SINAM, simply discontinuing statin is often insufficient and aggressive immunosuppression or immunomodulation therapy is needed to achieve disease remission. This case aims to demonstrate that statins can induce serious muscular diseases that require aggressive immunosuppression.

TITLE: Debilidad muscular proximal progresiva de inicio subagudo en un paciente anciano: descripción de un caso.Introducción. Las estatinas son de los medicamentos más recetados. Aunque las estatinas generalmente se toleran bien, pueden provocar efectos secundarios musculoesqueléticos. La miopatía autoinmune necrotizante inducida por estatinas (SINAM) es una afección rara y la prevalencia sólo es de 1 de cada 100.000 personas. Este trastorno se caracteriza por debilidad muscular simétrica progresiva y grave, elevación marcada de la creatincinasa y síntomas persistentes a pesar de la interrupción de la estatina. La electromiografía suele mostrar un patrón de miopatía irritable inespecífico, indistinguible de otras miopatías inflamatorias. La biopsia muscular muestra la presencia de fibras necróticas, fibras en regeneración sin células inflamatorias significativas y una regulación positiva difusa o focal de la expresión del complejo mayor de histocompatibilidad de clase I. Los anticuerpos anti-3-hidroxi-3-metilglutaril-coenzima A (anti-HMG-CoA) reductasa representan un rasgo serológico característico de la SINAM. Caso clínico. Presentamos a un paciente que desarrolló debilidad muscular progresiva después de tomar simvastatina durante los últimos siete años. En la presentación inicial, su nivel de creatincinasa fue de 2.954 U/L y los anticuerpos anti-HMG-CoA reductasa fueron positivos. La biopsia mostró rasgos miopáticos profundos con numerosas fibras necróticas, algunas fibras en regeneración e infiltrado de células inflamatorias perimisial, combinado con una sobreexpresión difusa del complejo mayor de histocompatibilidad de clase I. Se le diagnosticó SINAM, se suspendió la estatina y se inició una dosis alta de corticoides sistémicos, inmunoglobulina intravenosa y metotrexato. Después de tres meses de seguimiento, tuvo una mejora significativa en la fuerza muscular y el nivel de creatincinasa volvió a la normalidad. Conclusiones. En este caso, la exclusión de miopatías inflamatorias, trastornos musculares metabólicos y otras enfermedades neurológicas es necesaria para establecer un diagnóstico fidedigno. En la SINAM, la simple suspensión de las estatinas a menudo es insuficiente, y es necesaria una terapia de inmunosupresión o inmunomodulación agresiva para lograr la remisión de la enfermedad. Este caso tiene como objetivo demostrar que las estatinas pueden inducir enfermedades musculares graves que requieren una inmunosupresión agresiva.

Challenges in the diagnosis and management of immune-mediated necrotising myopathy (IMNM) in a patient on long-term statins.

Immune-mediated necrotising myopathy (IMNM) is a severe and poorly understood complication of statin use. Prompt management with immunosuppressive treatment is often needed to control the condition, which differs from the management of the more commonly recognised statin-induced myopathy. We present a case report and brief review of the literature regarding the pathogenesis, diagnosis, and management of anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) positive IMNM (HMGCR IMNM). There are no randomised clinical trials, but several smaller studies and cases suggest a triple therapy of corticosteroids, IVIG, and a corticosteroid-sparing immunosuppressant appears efficacious in patients with IMNM and proximal weakness. The mechanism of statin-induced IMNM is uncertain, and this is further complicated by the reports of HMGCR IMNM in statin-naïve patients, including children. We present a case of biopsy-confirmed HMGCR IMNM in a woman taking daily statins for treatment of hypercholesterolaemia for 4 years. She presented with symptoms consistent with a urinary tract infection (UTI), including muscle weakness. She was treated as an isolated case of UTI. One month later, she presented again with worsening weakness in her shoulders and hips. Creatine kinase was elevated, and MRI showed increased signal with STIR sequences in both thighs. Anti-HMGCR was positive and leg biopsy-confirmed necrotising changes. Stopping her statin prescription and a short course of prednisolone did not improve her muscle weakness. Adding methotrexate resulted in eventual resolution of her symptoms. IMNM should be considered as a differential in any patient taking statins presenting with muscle weakness, and this case suggests that immunosuppressant therapy in addition to cessation of statins is effective at treating IMNM. Clinical trials are needed to further investigate the efficacy of different combinations of immunosuppressants.

The effectiveness and side effects of pyridostigmine in the treatment of myasthenia gravis: a cross-sectional study.

Pyridostigmine is the most commonly used drug in the symptomatic treatment of myasthenia gravis (MG); however, research into its effectiveness and side effects is scarce. The aim of this study was to assess the effectiveness, prevalence of side effects and net benefit of pyridostigmine. All MG patients participating in the Dutch-Belgian myasthenia patient registry were included. A dynamic online questionnaire was developed to assess the effectiveness, side effects and net benefit of pyridostigmine. Out of 642 invited patients, 410 patients (64%) fully completed the questionnaire; 61% reported that they currently used pyridostigmine, 36% had discontinued pyridostigmine and 2% reported to never have used pyridostigmine. Patients reported a median effectiveness of 60, IQR 28-78 and net benefit of 65, IQR 45-84. Of all patients currently using pyridostigmine, 91% reported side effects (vs. 55% in the control group). Most frequently reported side effects were flatulence, urinary urgency, muscle cramps, blurred vision and hyperhidrosis. In the group of patients who discontinued pyridostigmine, side effects were the reason for discontinuation in 26%. Diarrhea, abdominal cramps and muscle twitching were the most frequently cited reasons to discontinue pyridostigmine. These results can be used to guide shared decision making prior to starting symptomatic treatment for MG.

Bone-Muscle Crosstalk: Musculoskeletal Complications of Chemotherapy.

PURPOSE OF REVIEW: Chemotherapy drugs combat tumor cells and reduce metastasis. However, a significant side effect of some chemotherapy strategies is loss of skeletal muscle and bone. In cancer patients, maintenance of lean tissue is a positive prognostic indicator of outcomes and helps to minimize the toxicity associated with chemotherapy. Bone-muscle crosstalk plays an important role in the function of the musculoskeletal system and this review will focus on recent findings in preclinical and clinical studies that shed light on chemotherapy-induced bone-muscle crosstalk. RECENT FINDINGS: Chemotherapy-induced loss of bone and skeletal muscle are important clinical problems. Bone antiresorptive drugs prevent skeletal muscle weakness in preclinical models. Chemotherapy-induced loss of bone can cause muscle weakness through both changes in endocrine signaling and mechanical loading between muscle and bone. Chemotherapy-induced changes to bone-muscle crosstalk have implications for treatment strategies and patient quality of life. Recent findings have begun to determine the role of chemotherapy in bone-muscle crosstalk and this review summarizes the most relevant clinical and preclinical studies.

Severe Generalized Weakness, Paraplegia following administration of Oxaliplatin in a patient with refractory T-cell non-Hodgkin lymphoma: A case report.

INTRODUCTION: Oxaliplatin is a third-generation platinum compound that used extensively for the treatment of various types of cancer especially gastrointestinal neoplasms. The main dose-limiting toxicities of oxaliplatin are hematological toxicity and peripheral sensory neuropathy. CASE REPORT: A 42-year-old man with refractory peripheral T-cell lymphoma (PTCL) was admitted to receive GEMOX chemotherapy regimen (gemcitabine, oxaliplatin). Three days after receiving his third cycle of chemotherapy regimen, he was re-admitted to the emergency department with complaint of severe generalized weakness, and paraplegia in the lower extremities. According to clinical and para-clinical findings, chronic sensorimotor polyneuropathy with ongoing axonal loss was confirmed. MANAGEMENT & OUTCOME: Intravenous dexamethasone 8 mg three times daily was started at the time of admission for the patient. Muscle weakness and sensory impairment improved dramatically within 10 days and the patient was able to walk with assistance. DISCUSSION: Several cases of neuropathy following oxaliplatin and only one case with gemcitabine-based chemotherapy regimen have been previously reported. However, motor symptoms are rare unless in the setting of acute neuropathy due to oxaliplatin. The most striking finding of our study was the incidence of a chronic sensorimotor axonaldemyelinating polyneuropathy in a patient who were subjected to oxaliplatin therapy. In conclusion, we report a case of severe generalized weakness and paraplegia following administration of Oxaliplatin.

Severe Motor Weakness Due to Disturbance in Peripheral Nerves Following Tisagenlecleucel Treatment.

BACKGROUND: Neurotoxicity is one of the dangerous complications of chimeric antigen receptor (CAR) T-cell therapy, while its pathophysiology remains to be fully understood. Motor weakness not associated with central nervous system (CNS) toxicity has rarely been reported after CAR T-cell therapy. CASE REPORT: A 42-year-old female with a refractory diffuse large B-cell lymphoma received tisagenlecleucel (tisa-cel) and developed cytokine release syndrome (CRS) on day 3. She was treated with tocilizumab and methylprednisolone, which resolved CRS promptly. On day 7, motor weakness in lower extremities appeared, and she gradually became unable to walk without showing any other symptoms attributed to CNS disturbances. Whereas dexamethasone and tocilizumab were ineffective, neuropathy improved after high dose chemotherapy followed by autologous stem cell transplantation. Nerve conduction study (NCS) in lower extremities showed a decline in compound muscle action potential amplitude along with worsening of motor weakness, which was restored after improvement of symptoms. Based on symptoms and NCS, her motor weakness was thought to be due to disturbance in peripheral nerves. CONCLUSION: This study reports a patient who developed severe motor weakness due to disturbance in peripheral nerves after tisa-cel therapy. Neurotoxicity of non-CNS origin should also be noted in CAR T-cell therapy.

Risk Factors and Medical Symptoms Associated With Electronic Vapor Product Use Among Adolescents and Young Adults.

The use of electronic vapor products (EVPs) has increased dramatically in the past decade. The objectives of our study were to examine the frequency of EVP use; to identify demographic characteristics, risk-taking behaviors, and beliefs about vaping; and to determine symptoms associated with EVPs among adolescents. A questionnaire addressing these objectives was administered to a convenience sample of subjects aged 12 to 23 years. Among 494 completed questionnaires, 80% of responders were considered experimenters/nonusers (never tried or tried one time) and 20% were considered frequent users (at least once a month). We identified demographic features and risk-taking behaviors associated with EVP use. In the previous 6 months, frequent users were more likely to report headache, cough, sleep disturbances, dehydration, weakness, racing heart, chest pain, and tremors. Our findings provide evidence to support efforts to decrease EVP use through screening, education, and preventative strategies.

Acute sunitinib neurotoxicity.

Sunitinib malate is a multitargeted oral tyrosine kinase inhibitor (TKI) which is used in treatment of metastatic renal cell carcinoma with side effects such as diarrhea, mucositis, asthenia and myelosuppression. Serious toxicity associated with sunitinib is a rare situation. However; there are few cases reported in the literature. As a result of the inhibition that is caused by sunitinib malate agent at the receptor level, vascular endothelial growth factor (VEGF) level increases. These increased VEGF levels are considered to having a positive contribution on neurological side effects. Neurotoxicity that is related with the usage of sunitinib malate for two weeks will be presented in this case report.

Intravenous immunoglobulins as first-line treatment in idiopathic inflammatory myopathies: a pilot study.

OBJECTIVES: We explored efficacy and safety of IVIg as first-line treatment in patients with an idiopathic inflammatory myopathy. METHODS: In this investigator-initiated phase 2 open-label study, we included 20 adults with a newly diagnosed, biopsy-proven idiopathic inflammatory myopathy, and a disease duration of less than 9 months. Patients with IBM and prior use of immunosuppressants were excluded. The standard treatment regimen consisted of IVIg (Privigen) monotherapy for 9 weeks: a loading dose (2 g/kg body weight) and two subsequent maintenance doses (1 g/kg body weight) with a 3-week interval. The primary outcome was the number of patients with at least moderate improvement on the 2016 ACR/EULAR Total Improvement Score. Secondary outcomes included time to improvement, the number of patients requiring rescue medication and serious adverse events. RESULTS: We included patients with DM (n = 9), immune-mediated necrotizing myopathy (n = 6), non-specific myositis/overlap myositis (n = 4) and anti-synthetase syndrome (n = 1). One patient was excluded from analyses because of minimal weakness resulting in a ceiling effect. Eight patients (8/19 = 42.0%; Clopper-Pearson 95% CI: 19.6, 64.6) had at least moderate improvement by 9 weeks. Of these, six reached improvement by 3 weeks. Seven patients required rescue medication due to insufficient efficacy and prematurely ended the study. Three serious adverse events occurred, of which one was pulmonary embolism. CONCLUSION: First-line IVIg monotherapy led to at least moderate improvement in nearly half of patients with a fast clinical response in the majority of responders. TRIAL REGISTRATION: Netherlands Trial Register identifier, NTR6160.

Quadriceps Weakness After Single-Shot Adductor Canal Block: A Multivariate Analysis of 1,083 Primary Total Knee Arthroplasties.

BACKGROUND: Adductor canal blocks (ACBs) are commonly employed in multimodal pain control for total knee arthroplasty (TKA) and minimize motor blockade compared with femoral nerve blocks. Quadriceps weakness may be associated with ACBs. The purpose of this study was to quantify the prevalence of clinically relevant quadriceps weakness after a single-shot ACB and to identify the factors that are associated with its diagnosis. METHODS: The study group consisted of 1,083 retrospectively reviewed consecutive TKAs that were performed with ACBs at an academic hip and knee center. Quadriceps weakness was quantified with a standardized rating system during the initial physical therapy evaluation, and 23 potential covariates were analyzed. RESULTS: The prevalence of quadriceps weakness was 9%. Increasing the dose of the ACB anesthetic per unit of body mass index (BMI) increased the probability of quadriceps weakness by 5.0 times (95% confidence interval [CI], 1.9 to 13.3; p = 0.001). The highest probability of quadriceps weakness (52.9%) was associated with women who received the highest anesthetic dose per unit of BMI and an epinephrine extender but no corticosteroid extender. CONCLUSIONS: The optimal volume of local anesthetic in ACBs to maintain pain control while minimizing quadriceps weakness has not yet been defined. Our observation that quadriceps weakness was associated with increasing doses of ACB anesthetic per unit of BMI suggests that more than traditional structural canal-fill parameters (i.e., filling the distal aspect of the adductor canal without spreading to the femoral triangle) should be considered when choosing injectates and injectate volumes for ACBs. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Neuromuscular and Clinical Recovery in Thoracic Surgical Patients Reversed With Neostigmine or Sugammadex.

BACKGROUND: Patients undergoing thoracoscopic procedures may be at high-risk for incomplete neuromuscular recovery and associated complications. The aim of this clinical investigation was to assess the incidence of postoperative residual neuromuscular blockade in adult thoracic surgical patients administered neostigmine or sugammadex when optimal dosing and reversal strategies for these agents were used. The effect of choice of reversal agent on hypoxemic events and signs and symptoms of muscle weakness were also determined. Additionally, operative conditions in each group were graded by surgeons performing the procedures. METHODS: Two hundred patients undergoing thoracoscopic surgical procedures were enrolled in this nonrandomized controlled trial. One hundred consecutive patients maintained at moderate levels of neuromuscular blockade were reversed with neostigmine (neostigmine group) followed by 100 consecutive patients given sugammadex to antagonize deeper levels of neuromuscular blockade (sugammadex group). Anesthetic and neuromuscular management were standardized. Surgeons rated operative conditions at the conclusion of the procedure on a 4-point scale (grade 1 = excellent to grade 4 = poor). Train-of-four ratios were measured immediately before extubation and at PACU admission (primary outcomes). Postoperatively, patients were assessed for adverse respiratory events and 11 signs and 16 symptoms of muscle weakness. RESULTS: The 2 groups were similar in intraoperative management characteristics. The percentage of patients with residual neuromuscular blockade, defined as a normalized train-of-four ratio <0.9, was significantly greater in the neostigmine group than the sugammadex group at both tracheal extubation (80% vs 6%, respectively, P < .0001) and PACU admission (61% vs 1%, respectively, P < .0001). Patients in the neostigmine group had less optimal operative conditions (median score 2 [good] versus 1 [excellent] in the sugammadex group; P < .0001), and more symptoms of muscle weakness were present in these subjects (median number [interquartile range] 4 [1-8] vs 1 [0-2] in the sugammadex group, P < .0001). No differences between groups in adverse airway events were observed. CONCLUSIONS: Despite the application of strategies documented to reduce the risk of residual neuromuscular blockade, a high percentage of thoracoscopic patients whose neuromuscular blockade was reversed with neostigmine were admitted to the PACU with clinical evidence of residual paralysis. In contrast, muscle weakness was rarely observed in patients whose neuromuscular blockade was antagonized with sugammadex.

An Exploratory Study on Physical Function in Stem Cell Transplant Patients Undergoing Corticosteroid Treatment for Acute Graft-Versus-Host-Disease.

ABSTRACT: Acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation is treated with corticosteroids, placing patients at risk for steroid myopathy. In this single-arm cohort study, 23 patients who were started on high-dose corticosteroids for acute graft-versus-host disease underwent a series of functional tests (baseline and days 14, 28, and 56): 6-min walk test, hip flexor and knee extensor strength via dynamometry, five times sit-to-stand, Brooke scale for myopathy, modified Adult Myopathy Assessment Tool, and manual muscle testing. Participants were prescribed home exercises including walking and resistance exercises, with low adherence. Fifteen (63%) participants were male and median (range) age was 60 (36-70) yrs. Median (range) corticosteroid duration and cumulative equivalent methylprednisolone dose were 66 (22-165) days and 3625 (1020-11720) mg, respectively. At day 14, there was a significant decline in five times sit-to-stand (P = 0.0132), knee extensor (P = 0.0182), and manual muscle testing (P = 0.0466). Functional tests negatively associated with cumulative corticosteroid dose included 6-min walk test distance (P = 0.0103), hip flexor strength (P = 0.0262), knee extensor strength (P = 0.0369), and manual muscle testing strength (P = 0.0319). Five times sit-to-stand was positively associated with corticosteroid dose (P = 0.0003). In conclusion, stem cell transplant patients receiving high-dose corticosteroids for acute graft-versus-host disease are at risk for weakness detected as early as day 14. Increasing adherence to exercise may mitigate these changes.

[A case of colchicine myopathy in which the long-term use of colchicine hampered the recovery].

A 69-year-old woman was admitted to our hospital because of limb weakness. She was diagnosed to have chronic renal failure due to diabetes mellitus and had suffered from pericardial effusion at 67 years of age. She started taking colchicine 18 months before admission and thereafter gradually developed muscle weakness in her limbs and had become bedridden at the time of admission. The withdrawal of colchicine improved her limb weakness, and therefore we diagnosed her to have colchicine myopathy. Her muscle strength did not completely recover even after six months from cessation of colchicine. It was suggested that renal failure and muscle disuse had prevented the full recovery of her muscles in addition to the long-term use of colchicine. Typical colchicine myopathy improves rapidly, but the long-term use of colchicine is considered to cause muscle weakness. Although the CK level was elevated, the elevated CK and myopathy had been overlooked because the CK baseline was low due to the patient's small amount of muscle mass. Moreover, the estimated GFR was recorded to be higher than her actual renal function due to her small amount of muscle mass, therefore the risk of colchicine myopathy in this case remained unrecognized.

Systemic muscle wasting and coordinated tumour response drive tumourigenesis.

Cancer cells demand excess nutrients to support their proliferation, but how tumours exploit extracellular amino acids during systemic metabolic perturbations remain incompletely understood. Here, we use a Drosophila model of high-sugar diet (HSD)-enhanced tumourigenesis to uncover a systemic host-tumour metabolic circuit that supports tumour growth. We demonstrate coordinate induction of systemic muscle wasting with tumour-autonomous Yorkie-mediated SLC36-family amino acid transporter expression as a proline-scavenging programme to drive tumourigenesis. We identify Indole-3-propionic acid as an optimal amino acid derivative to rationally target the proline-dependency of tumour growth. Insights from this whole-animal Drosophila model provide a powerful approach towards the identification and therapeutic exploitation of the amino acid vulnerabilities of tumourigenesis in the context of a perturbed systemic metabolic network.

Hydroxychloroquine-Induced Toxic Myopathy Causing Diaphragmatic Weakness and Lung Collapse Requiring Prolonged Mechanical Ventilation.

A 42-year-old woman with juvenile idiopathic arthritis was treated with anakinra, corticosteroids, and hydroxychloroquine when she developed chronic hypoxic respiratory myopathy. She was admitted to the intensive care unit for acute hypercapnic respiratory failure and required prolonged intubation, subsequent tracheostomy, and long-term ventilatory support due to multiple failed spontaneous breathing trials after discontinuation of anakinra and steroids. Muscle biopsy revealed type II fiber atrophy with the accumulation of autophagosomes and vacuoles presenting as curvilinear bodies, elevated MHC class I antigen expression, and infiltration by CD68+ macrophages and CD8+ T cells. Type II fiber atrophy was attributed to corticosteroid use and curvilinear bodies due to blockade of autophagy by hydroxychloroquine. After hydroxychloroquine was discontinued, the patient recovered to her prehospitalization baseline.

Macrophagic myofasciitis and subcutaneous pseudolymphoma caused by aluminium adjuvants.

Aluminium hydroxide is a well-known adjuvant used in vaccines. Although it can enhance an adaptive immune response to a co-administered antigen, it causes adverse effects, including macrophagic myofasciitis (MMF), subcutaneous pseudolymphoma, and drug hypersensitivity. The object of this study is to demonstrate pediatric cases of aluminium hydroxide-induced diseases focusing on its rarity, under-recognition, and distinctive pathology. Seven child patients with biopsy-proven MMF were retrieved from the Seoul National University Hospital (SNUH) pathology archives from 2015 to 2019. The medical records and immunisation history were reviewed, and a full pathological muscle examination was carried out. The mean age was 1.7 years (8.9-40 months), who had records of vaccination against hepatitis B, hepatitis A, and tetanus toxoid on the quadriceps muscle. The chief complaints were muscle weakness (n = 6), delayed motor milestones (n = 6), instability, dysarthria, and involuntary movement (n = 1), swallowing difficulty (n = 1), high myopia (n = 1), and palpable subcutaneous nodules with skin papules (n = 1). Muscle biopsy showed MMF (n = 6) and pseudolymphoma (n = 1) with pathognomic basophilic large macrophage infiltration, which had distinctive spiculated inclusions on electron microscopy. The intracytoplasmic aluminium was positive for PAS and Morin stains. Distinctive pathology and ultrastructure suggested an association with aluminium hydroxide-containing vaccines. To avoid misdiagnosis and mistreatment, we must further investigate this uncommon condition, and pharmaceutical companies should attempt to formulate better adjuvants that do not cause such adverse effects.

Modification of Neuromuscular Junction Protein Expression by Exercise and Doxorubicin.

PURPOSE: Doxorubicin (DOX) is a highly effective antitumor agent widely used in cancer treatment. However, it is well established that DOX induces muscular atrophy and impairs force production. Although no therapeutic interventions exist to combat DOX-induced muscle weakness, endurance exercise training has been shown to reduce skeletal muscle damage caused by DOX administration. Numerous studies have attempted to identify molecular mechanisms responsible for exercise-induced protection against DOX myotoxicity. Nevertheless, the mechanisms by which endurance exercise protects against DOX-induced muscle weakness remain elusive. In this regard, impairments to the neuromuscular junction (NMJ) are associated with muscle wasting, and studies indicate that physical exercise can rescue NMJ fragmentation. Therefore, we tested the hypothesis that exercise protects against DOX-induced myopathy by preventing detrimental changes to key proteins responsible for maintenance of the NMJ. METHODS: Female Sprague-Dawley rats were assigned to sedentary or exercise-trained groups. Exercise training consisted of a 5-d treadmill habituation period followed by 10 d of running (60 min·d, 30 m·min, 0% grade). After the last training bout, exercise-trained and sedentary animals were paired with either placebo (saline) or DOX (20 mg·kg i.p.) treatment. Two days after drug treatment, the soleus muscle was excised for subsequent analyses. RESULTS: Our results indicate that endurance exercise training prevents soleus muscle atrophy and contractile dysfunction in DOX-treated animals. These adaptations were associated with the increased expression of the following neurotrophic factors: brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor, nerve growth factor, and neurotrophin-3. In addition, exercise enhanced the expression of receptor-associated protein of the synapse and the acetylcholine receptor (AChR) subunits AChRß, AChRδ, and AChRγ in DOX-treated animals. CONCLUSION: Therefore, upregulating neurotrophic factor and NMJ protein expression may be an effective strategy to prevent DOX-induced skeletal muscle dysfunction.

Checkpoint inhibitor myasthenia-like syndrome and myositis associated with extraocular muscle atrophy.

A patient with metastatic melanoma developed myasthenia-like syndrome and paraspinal myositis with subsequent extraocular muscle atrophy associated with immune checkpoint inhibitor treatment. MRI scan of the ocular muscles on admission was normal, however 3 months later revealed significant extraocular muscle atrophy.

Opioid- and Motor-sparing with Proximal, Mid-, and Distal Locations for Adductor Canal Block in Anterior Cruciate Ligament Reconstruction: A Randomized Clinical Trial.

BACKGROUND: The ideal location for single-injection adductor canal block that maximizes analgesia while minimizing quadriceps weakness after painful knee surgery is unclear. This triple-blind trial compares ultrasound-guided adductor canal block injection locations with the femoral artery positioned medial (proximal adductor canal), inferior (mid-adductor canal), and lateral (distal adductor canal) to the sartorius muscle to determine the location that optimizes postoperative analgesia and motor function. The hypothesis was that distal adductor block has (1) a superior opioid-sparing effect and (2) preserved quadriceps strength, compared with proximal and mid-locations for anterior cruciate ligament reconstruction. METHODS: For the study, 108 patients were randomized to proximal, mid-, or distal adductor canal injection locations for adductor canal block. Cumulative 24-h oral morphine equivalent consumption and percentage quadriceps strength decrease (maximum voluntary isometric contraction) at 30 min postinjection were coprimary outcomes. The time to first analgesic request, pain scores, postoperative nausea/vomiting at least once within the first 24 h, and block-related complications at 2 weeks were also evaluated. RESULTS: All patients completed the study. Contrary to the hypothesis, proximal adductor canal block decreased 24-h morphine consumption to a mean ± SD of 34.3 ± 19.1 mg, (P < 0.0001) compared to 64.0 ± 33.6 and 65.7 ± 22.9 mg for the mid- and distal locations, respectively, with differences [95% CI] of 29.7 mg [17.2, 42.2] and 31.4 mg [21.5, 41.3], respectively, mostly in the postanesthesia care unit. Quadriceps strength was similar, with 16.7%:13.4%:15.3% decreases for proximal:mid:distal adductor canal blocks. The nausea/vomiting risk was also lower with proximal adductor canal block (10 of 34, 29.4%) compared to distal location (23 of 36, 63.9%; P = 0.005). The time to first analgesic request was longer, and postoperative pain was improved up to 6 h for proximal adductor canal block, compared to mid- and distal locations. CONCLUSIONS: A proximal adductor canal injection location decreases opioid consumption and opioid-related side effects without compromising quadriceps strength compared to mid- and distal locations for adductor canal block in patients undergoing anterior cruciate ligament reconstruction.