Distribution and severity of weakness among patients with polymyositis, dermatomyositis and juvenile dermatomyositis

George Washington University, School of Medicine and Health Sciences, Washington, DC, USA.
Rheumatology (Oxford, England) (Impact Factor: 4.48). 12/2008; 48(2):134-9. DOI: 10.1093/rheumatology/ken441
Source: PubMed


To describe the distribution and severity of muscle weakness using manual muscle testing (MMT) in 172 patients with PM, DM and juvenile DM (JDM). The secondary objectives included characterizing individual muscle group weakness and determining associations of weakness with functional status and myositis characteristics in this large cohort of patients with myositis.
Strength was assessed for 13 muscle groups using the 10-point MMT and expressed as a total score, subscores based on functional and anatomical regions, and grades for individual muscle groups. Patient characteristics and secondary outcomes, such as clinical course, muscle enzymes, corticosteroid dosage and functional status were evaluated for association with strength using univariate and multivariate analyses.
A gradient of proximal weakness was seen, with PM weakest, DM intermediate and JDM strongest among the three myositis clinical groups (P < or = 0.05). Hip flexors, hip extensors, hip abductors, neck flexors and shoulder abductors were the muscle groups with the greatest weakness among all three clinical groups. Muscle groups were affected symmetrically.
Axial and proximal muscle impairment was reflected in the five weakest muscles shared by our cohort of myositis patients. However, differences in the pattern of weakness were observed among all three clinical groups. Our findings suggest a greater severity of proximal weakness in PM in comparison with DM.

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    • "Granulomatosis with polyangiits is very rare in children and, although it appears to be the same disease observed in adults, it is not known if childhood presentations are characterized by differences in the frequency of some clinical features well described in adults. Indeed, in other connective tissue diseases, such as systemic lupus erythematosus or juvenile dermatomyositis, the frequency of several clinical manifestations differed from those observed in adults [18,19]. "
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    ABSTRACT: Background Granulomatosis with polyangiitis (GPA), formerly known as Wegener’s granulomatosis (WG), belongs to the group of ANCA-associated necrotizing vasculitides. This study describes the clinical picture of the disease in a large cohort of GPA paediatric patients. Children with age at diagnosis ≤ 18 years, fulfilling the EULAR/PRINTO/PRES GPA/WG classification criteria were extracted from the PRINTO vasculitis database. The clinical signs/symptoms and laboratory features were analysed before or at the time of diagnosis and at least 3 months thereafter and compared with other paediatric and adult case series (>50 patients) derived from the literature. Findings The 56 children with GPA/WG were predominantly females (68%) and Caucasians (82%) with a median age at disease onset of 11.7 years, and a median delay in diagnosis of 4.2 months. The most frequent organ systems involved before/at the time of diagnosis were ears, nose, throat (91%), constitutional (malaise, fever, weight loss) (89%), respiratory (79%), mucosa and skin (64%), musculoskeletal (59%), and eye (35%), 67% were ANCA-PR3 positive, while haematuria/proteinuria was present in > 50% of the children. In adult series, the frequency of female involvement ranged from 29% to 50% with lower frequencies of constitutional (fever, weight loss), ears, nose, throat (oral/nasal ulceration, otitis/aural discharge), respiratory (tracheal/endobronchial stenosis/obstruction), laboratory involvement and higher frequency of conductive hearing loss than in this paediatric series. Conclusions Paediatric patients compared to adults with GPA/WG have similar pattern of clinical manifestations but different frequencies of organ involvement.
    Pediatric Rheumatology 05/2014; 12(1):18. DOI:10.1186/1546-0096-12-18 · 1.61 Impact Factor
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    • "The subtypes of calcinosis were defined according to the classification by Blane et al. [10]. Global weakness was defined as weakness that extended beyond the usual muscles identified as most often affected in JDM (that is, the hip flexors, hip extensors, hip abductors, neck flexors and shoulder abductors) and therefore included peripheral weakness (hands and feet) and abdominal muscles [11]. Weakness was assessed by standard manual muscle testing. "
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    ABSTRACT: To describe Juvenile dermatomyositis (JDM) that has rarely been reported in Sub-Saharan Africa in children. Retrospective record review of children with JDM attending a tertiary hospital in South Africa. Twenty-one children (16 female, five male) with JDM had a mean (SD) age at presentation of 9.8 (3.3) years. Mean follow-up period was 2.6 (2.2) years. The commonest presenting features were skin rash (71%), muscle weakness (71%), inflammatory arthritis (42%) and calcinosis (29%). The cumulative frequency of calcinosis was 71%. Skin vasculitis was present in 9(43%), and 7 (33%) had Staphylococcus aureus infections. Calcinosis was strongly associated with vasculitis; 11/15 (73.3%) with calcinosis had vasculitis versus 0/6 without vasculitis (p = 0.003). Patients with calcinosis had significantly lower creatinine kinase (CK) levels compared to those without calcinosis [mean (SD) 272 U/L (401) vs. 2414 U/L (3201), respectively, p = 0.016]. All children with calcinosis had Staphylococcus aureus infection, but there was no significant difference in their duration of symptoms to presentation. Joint contractures, occurring in eight patients (38%), were associated with a significantly lower age at presentation [mean (SD) 6.8(2.8) vs. 11.6(2.1) years (no contractures) p = 0.0003], and significantly higher CRP and ESR levels. Three patients were lost to follow-up, two died. In the remaining 16 patients: 10 (47%) experienced remission, 2 relapsed and 4 persistent active disease. African children with JDM have increased vasculitic disease and high levels of calcinosis with low muscle enzymes, particularly CK. Younger children are at higher risk of contractures and disability. Patients are at high risk of developing Staphylococcus aureus infection. Rapid and aggressive therapy is necessary.
    Pediatric Rheumatology 01/2014; 12(1):2. DOI:10.1186/1546-0096-12-2 · 1.61 Impact Factor
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    • "The idiopathic inflammatory myopathies, including polymyositis (PM) and dermatomyositis (DM), are characterized by muscle weakness and poor muscle endurance, especially in proximal muscles [1,2]. The mechanisms that lead to muscle weakness are not fully clarified but both immune-mediated and non-immune-mediated mechanisms are thought to be involved in the disease process and the latter mechanisms include endoplasmic reticulum (ER) stress, hypoxia, autophagy and mitochondrial pathology [3-5]. "
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    ABSTRACT: This randomized, controlled study on patients with polymyositis or dermatomyositis was based on three hypotheses: Patients display impaired endurance due to reduced aerobic capacity and muscle weakness, endurance training improves their exercise performance by increasing the aerobic capacity, and endurance training has general beneficial effects on their health status. In the first part of this study, we compared 23 patients with polymyositis or dermatomyositis with 12 age- and gender-matched healthy controls. A subgroup of patients were randomized to perform a 12 week endurance training program (exercise group, n=9) or to a non-exercising control group (n=6). We measured maximal oxygen uptake (VO2 max) and the associated power output during a progressive cycling test. Endurance was assessed as the cycling time to exhaustion at 65% of VO2 max. Lactate levels in the vastus lateralis muscle were measured with microdialysis. Mitochondrial function was assessed by measuring citrate synthase (CS) and beta-hydroxyacyl-CoA dehydrogenase (beta-HAD) activities in muscle biopsies. Clinical improvement was assessed according to the International Myositis Assessment and Clinical Studies Group (IMACS) improvement criteria. All assessors were blinded to the type of intervention (i.e. training or control). Exercise performance and aerobic capacity were lower in patients than in healthy controls, whereas lactate levels at exhaustion were similar. Patients in the exercise group increased their cycling time, aerobic capacity and CS and beta-HAD activities, whereas lactate levels at exhaustion decreased. Six of nine patients in the exercise group met the IMACS improvement criteria. Patients in the control group did not show any consistent changes during the 12 week study. Polymyositis and dermatomyositis patients have impaired endurance, which could be improved by 12 weeks of endurance training. The clinical improvement corresponds to increases in aerobic capacity and muscle mitochondrial enzyme activities. The results emphasize the importance of endurance exercise in addition to immunosuppressive treatment of patients with polymyositis or dermatomyositis. Trial registration: Identifier NCT01184625.
    Arthritis research & therapy 08/2013; 15(4):R83. DOI:10.1186/ar4263 · 3.75 Impact Factor
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