[Diagnosis of inflammatory myopathy; usefulness of 99mTc MDP scintigraphy and muscle MRI for determination of affected sites]

We studied the effectiveness of 99mTc-MDP (methylendiphosphate) scintigraphy in imaging inflammatory myopathy. The three subjects including 1 male and 2 female patients had high creatine kinase (CK) levels and proximal dominant muscle weakness. In whole body muscle surveillance by 99mTc-MDP scintigraphy, abnormal 99mTc-MDP accumulation was found in the extremities of all patients. The sites with high 99mTc-MDP accumulation showed high intensity on T2 weighted MR imaging, suggesting an inflammatory process. Muscle biopsy was performed on two patients from the muscles with the abnormal MRI findings, which showed the diagnostic finding of inflammatory changes. Because muscle involvement in inflammatory myopathy differs from muscle to muscle, it is sometimes difficult to choose appropriate muscle biopsy sites for diagnostic purposes. Affected muscles are more easily identified by using 99mTc-MDP muscle scintigraphy and muscle MRI, therefore, a correct diagnosis and choice of biopsy site can be made. 99mTc-PYP scintigraphy is permitted for use in myocardial infarction alone and 111In-antimyosin scintigraphy is not available in Japan. Therefore, we recommend 99mTc-MDP scintigraphy for diagnosis of inflammatory myopathy and for determination of muscle biopsy sites.

Development of validated disease activity and damage indices for the juvenile idiopathic inflammatory myopathies. II. The Childhood Myositis Assessment Scale (CMAS): a quantitative tool for the evaluation of muscle function. The Juvenile Dermatomyositis Disease Activity Collaborative Study Group

OBJECTIVE

To develop, validate, and determine the measurement characteristics of a quantitative tool for assessing the severity of muscle involvement in children with idiopathic inflammatory myopathies.

METHODS

The Childhood Myositis Assessment Scale (CMAS) was developed from 2 existing observational functional assessment tools to assess muscle function in the areas of strength and endurance across a wide range of ability and ages. The 14 ordinal items included were chosen to assess primarily axial and proximal muscle groups and are ranked with standard performance and scoring methods. Following the development of the CMAS, a training video and written instructions were developed and reviewed by the physicians participating in this study. Subsequently, utilizing a randomized block design, 12 physicians independently scored 10 children (9 with dermatomyositis, 1 with polymyositis; ages 4-15 years) twice in one day (morning and afternoon) on the CMAS. A pediatric physical therapist performed quantitative manual muscle strength testing (MMT) twice on each child (morning and afternoon), including the neck, trunk, and proximal and distal extremity muscle groups.

RESULTS

The CMAS has a potential range of 0-51, with higher scores indicating greater muscle strength and endurance. The observed mean for the 10 patients was 36.4 (median 44, SD 14.1, observed range 5-51). The total score for the CMAS correlated with the physician's global assessment (by visual analog scale) of disease activity, the MMT score, serum creatine kinase level, and the Juvenile Arthritis Functional Assessment Report score. The score on the CMAS was not correlated with patient age. Interrater reliability (Kendall's coefficient of concordance) ranged from 0.77 to 1.0 for individual items (all P < 0.001), and overall, it was 0.95 (P < 0.001). Intrarater reliability for the individual physicians was measured by correlation of the CMAS scores for each patient on 2 separate evaluations and ranged from 0.97 to 0.99, with an overall correlation for all physicians of 0.98 (all P < 0.001).

CONCLUSION

The CMAS demonstrated an acceptable range of observed scores, excellent convergent validity, and excellent inter- and intrarater reliability. The CMAS is validated to quantitatively assess muscle function in the areas of strength and endurance in children with idiopathic inflammatory myopathies. It can be used in routine clinical care as well as therapeutic trials.

Muscle infections caused by Salmonella species: case report and review

We describe a patient with salmonella pyomyositis and review 30 other cases reported during the past 4 decades. Men outnumbered women by 2.9 to 1, and the median age of the patients was 51 years. Approximately one-half the cases were caused by Salmonella enteritidis. Infected vascular aneurysms were observed in seven patients. Prior salmonella infections and local trauma or lesions were common. Diverse underlying conditions, mainly diabetes and human immunodeficiency virus infection, were present in 81% of the patients, and the psoas muscle was involved in 55% of the cases. One-third of the patients died, and relapses were common after a median time of 5 weeks (range, 4.5-27 weeks) in those who survived. Most patients had anemia, and pathogens were recovered from blood samples from two-thirds of the patients. Salmonella should be considered as a causative agent of muscle infections in the appropriate clinical setting, particularly in patients with underlying diseases or preexisting vascular aneurysms.

Muscle involvement in leprosy. Study of the anterior tibial muscle in 40 patients

The involvement of skeletal striated muscle in leprosy is considered secondary due to peripheral neuropathy, but some studies point it to a primary muscle lesion. In order to investigate the muscle involvement in leprosy, we studied 40 patients (lepromatous 23, tuberculoid 13, borderline 2 and indeterminate 2). The motor nerve conduction of the peroneal nerves had a reduction of the velocity, decreased compound muscle action potential and sometimes absence of potentials. The electromyographic study of the anterior tibial muscle showed signs of recent and chronic denervation in 77.5% of the cases and no myopathic potentials. The anterior tibial muscle biopsy revealed denervation in 45% of the cases, interstitial inflammatory myopathy in 30% and mixed (myopathic and neuropathic) pattern in 12.5%. Acid fast bacillus was detected in 25% of the cases, always in the interstitial tissue. Inflammatory reaction was present in the interstitial space and in patients with the lepromatous type. The histological findings clearly defined the presence of the so-called "Leprous Interstitial Myositis" on the top of denervation signs.

Acquired binocular horizontal diplopia

Binocular horizontal diplopia is an important symptom that may foretell or help localize and characterize various neurologic and neuromuscular disorders. An appropriate evaluation requires a careful and complete neuro-ophthalmic history and examination. This review focuses on the differential diagnosis of binocular horizontal diplopia.

Primary Sjögren's syndrome with severe central nervous system disease

OBJECTIVE

Central nervous system (CNS) involvement in primary Sjögren's syndrome (pSS) is controversial with regard to frequency, significance, and etiology.

METHODS

We describe a young woman with pSS and severe CNS disease and review the literature on the pathophysiology, clinical significance, symptoms, diagnostic examinations, and treatment of CNS disease with concomitant pSS (CNS-SS).

RESULTS

Our patient with pSS had a 5-month history of benign lymphadenopathy and myositis, after which she developed severe CNS disease, vasculitic lesions on her hands, and a neurogenic bladder attributable to spinal cord involvement. The diagnosis was based on the clinical picture and the results of a brain magnetic resonance imaging (MRI) scan, electroencephalography (EEG), and cerebrospinal fluid (CSF) analysis. The disease did not respond to corticosteroids, but the administration of cyclophosphamide resulted in recovery. In the literature, the incidence of CNS-SS varies widely, from rare to incidence rates of 20% to 25%. The clinical picture is diverse, ranging from mild cognitive symptoms to fatal cerebrovascular accidents. The pathophysiology of CNS-SS is unclear, specific diagnostic methods are not available, and diagnosis is based on the clinical picture and a combination of examinations. MRI is the most sensitive test and cerebral angiography the most specific. CSF reflects involvement of the leptomeninges, and EEG is nonspecific. There are no controlled studies of the treatment of CNS-SS. Regimens for vasculitis are commonly used.

CONCLUSIONS

CNS-SS is uncommonly recognized and difficult to diagnose. Increasingly accurate and available diagnostic examinations will yield more information about the association of CNS disease with pSS.

Focal myositis presenting with radial nerve palsy

Focal myositis is a rare inflammatory pseudotumor of skeletal muscle which usually has a benign course. We report a 56-year-old woman with a painful mass in the left arm with a radial nerve palsy. Magnetic resonance imaging (MRI) of the left arm showed a mass in the triceps muscle that was suggestive of a soft-tissue sarcoma. Electromyography showed a severe radial neuropathy involving both motor and sensory axons. An open biopsy showed focal myositis. Treatment with corticosteroids resulted in complete disappearance of the mass clinically and by MRI, without recurrence for more than 2 years. Radial nerve function also recovered completely. As a treatable cause of focal neuropathy, focal myositis should be included in the differential diagnosis of a muscle mass.

Vesicoureteral reflux in a boy presenting with difficulty in walking

BACKGROUND

We report an uncommon case who presented himself at our hospital with main complaints of high fever and difficulty in walking due to pain on extension of his right lower extremity.

METHODS

He was diagnosed, through investigation of his urinary tract, as having secondary psoas pyomyositis spread from acute pyelonephritis caused by vesicoureteral reflux.

RESULTS

He was successfully managed firstly by antibiotic therapy, followed by the correction of reflux by ureteroneovesicostomy.

[Macrophagic myofasciitis: description and etiopathogenic hypotheses. Study and Research Group on Acquired and Dysimmunity-related Muscular Diseases (GERMMAD) of the French Association against Myopathies (AFM)]

PURPOSE

A new type of inflammatory myopathy of unknown etiology has recently been described in France. The myopathy, called macrophagic myofasciitis, had never been described in the literature.

METHODS

In December 1998, 35 cases of macrophagic myofasciitis were reported, showing an increase in its incidence since the description of the first case in 1993. The first 22 cases are described.

RESULTS

The 22 patients were each referred with a presumptive diagnosis of either polymyositis (11 patients), polymyalgia rheumatica (5 patients), mitochondrial cytopathy (4 patients), or congenital myopathy or muscle dystrophy (1 patient for each). Clinical symptoms included myalgias (91%), arthralgias (68%), marked asthenia (55%), muscle weakness (45%), and fever (32%). Laboratory findings included elevated CK levels (50%) and a marked increased in the erythrocyte sedimentation rate (37%). Electromyographic recordings showed the existence of myopathy (35%). Muscle biopsy showed a unique pattern characterized by: (i) centripetal infiltration of the epimysium, perimysium and perifascicular endomysium by non epitheloid, cells of the monocyte/macrophage lineage (CD68+, CD1a-, S100-) with both large cytoplasm and PAS-positive content; (ii) absence of necrosis, of both epithelioid and giant cells, and of mitotic figures; (iii) occasional CD8+ T-cells; and, (iiii) minimal myocyte suffering. The disease symptoms were easily distinguishable from those of sarcoid myopathy and fasciitis-panniculitis syndromes. Infectious diseases known to be associated with reactive histiocytosis, including Whipple's disease, Mycobacterium avium intracellulare infection and malakoplakia, could not be documented. Patients' condition improved under corticosteroid therapy, associated or not with non-specific antibiotic therapy.

CONCLUSION

A new inflammatory muscle disorder of unknown etiology, characterized by a distinctive pathological pattern of macrophagic myofasciitis, is emerging in France. Diagnosis is based on muscular biopsy. Numerous clinical, epidemiological and etiopathologic studies initiated by the GERMMAD (Groupe d'études et de recherche sur les maladies musculaires acquises) are in progress.

The diagnostic power of motor unit potential analysis: an objective bayesian approach

The notion of a "myopathic" or "neuropathic" electromyogram (EMG) is usually based on qualitative visual and acoustical impressions. Conventional quantification defines abnormality but not diagnosis, which requires interpretation of patterns of change. Discriminant analysis is a model for this multivariate decision. It tells how probable it is that a motor unit potential (MUP) comes from a normal, myopathic, or neuropathic muscle. Accumulation of single MUP information by a sequential Bayesian algorithm produced diagnostic probabilities above 0.95 in 91% of all muscles (223 biceps brachii muscles from 80 patients with motoneuron disorders, 56 patients with neuropathies, 71 patients with myopathies, and 34 controls). Two muscles from patients with neurogenic disorders were misclassified as "myopathic." Misclassification was more frequent only in myositis (4 of 28 muscles) and in oculopharyngeal muscular dystrophy (2 of 4 muscles). MUP discriminant classification was as sensitive as, and more specific than, conventional quantitative EMG, which discriminated between myopathic and neuropathic in only 22% of the muscles. This rate was 59% for discriminant analysis. As a knowledge-based expert system, MUP discriminant analysis successfully distinguishes between myopathic, neuropathic, and unclassifiable MUP samples. It discloses more information than conventional quantitative MUP analysis.

MRI of tuberculous pyomyositis

PURPOSE

The purpose of this article is to describe the findings of MRI in tuberculous pyomyositis (PM).

METHOD

The MR images of four proven cases of tuberculous PM were retrospectively reviewed and analyzed with clinical and laboratory findings. The location, signal intensity on T1- and T2-weighted spin echo images, presence of abscess, signal intensity of peripheral rim, patterns of contrast enhancement, and associated findings were evaluated.

RESULTS

On MR images, all cases demonstrated low signal intensity on T1-weighted images and high signal intensity on T2-weighted images in a single muscle. Abscess was seen in all cases. Peripheral rim showed subtle hyperintensity on T1-weighted images and hypointensity on T2-weighted images. After gadolinium infusion, peripheral rim enhancement was observed in all cases. Cellulitis was associated in one case. The patients clinically presented with a palpable mass of long duration.

CONCLUSION

Tuberculous PM shows characteristic findings of a well demarcated abscess with rim enhancement at MRI and can be distinguished from other soft tissue masses.

Influence of age on characteristics of polymyositis and dermatomyositis in adults

In a retrospective study of 79 consecutive patients, we evaluated characteristics of polymyositis (PM) and dermatomyositis (DM) and compared clinical presentation, biochemical findings, histologic changes, evolution, complications, and mortality rate of elderly patients (aged > or = 65 yr) and younger patients (aged < or = 64 yr) at the onset of PM/DM. We found a high prevalence of PM/DM in elderly patients: 23 patients (29%) were aged 65 years or over. We also found that esophageal involvement (34.8% versus 16.1%, respectively) and bacterial pneumonia related to both ventilatory insufficiency and esophageal impairment (21.7% versus 5.4%, respectively) were more common in elderly patients compared with younger patients, resulting in increased morbidity and mortality rates. Moreover, malignancy frequency was higher in elderly patients compared with younger patients (47.8% versus 9.1%, respectively, p = 0.0001), particularly patients with DM (10/11). Fifty percent of malignancies were colon malignancies in elderly patients. Erythrocyte sedimentation rate, C-reactive protein, fibrinogen, and ferritin levels were also higher in the elderly patient group compared with the younger group, and the presence of serum hypoprotidemia, hypoalbuminemia, and anemia was more frequent. Finally, PM/DM complete remission was less frequent (13.6% versus 41.1%) and the mortality rate (47.8% versus 7.3%) was higher in elderly patients than in younger patients. The main causes of death in elderly patients were bacterial pneumonia, due to ventilatory insufficiency and esophageal impairment, and malignancies. Our findings therefore indicate that PM/DM-related esophageal and lung involvement should be systematically searched for in elderly patients. Esophageal manometry and pulmonary function tests should become an integral part of initial evaluation in elderly patients for early detection of impairment. Moreover, as we observed a marked overrepresentation of colon cancer in elderly patients with DM, we suggest that the search for malignancies in elderly patients with DM should include lower gastrointestinal tract investigations.

[Myositis in the presence of slightly elevated creatine kinase values]

The clinical picture with, among other things, muscular swelling, fever and nocturnal sweating in three males aged 30, 37 and 52 years, suggested a neoplasm and sepsis. Ultimately, they were found to suffer from focal myositis, localized nodular myositis and polymyositis, respectively. The ESR and leukocyte counts were increased, the serum creatinine kinase (CK) activity was normal or slightly increased. The symptoms decreased after prednisone treatment. Both localized and generalized inflammatory muscular diseases may be present without the serum CK activity being raised.

Clinical and laboratory manifestations of systemic sclerosis (scleroderma) in Black South Africans

A retrospective study of systemic sclerosis (SSc) in Blacks attending a tertiary hospital on the Witwatersrand, South Africa, was undertaken. The female:male ratio of the 63 patients was 4.6:1 and the mean age of onset of SSc was 36.1 yr. Four of the 11 males were ex-goldminers and nine females resided close to goldmines. Forty-one patients had diffuse cutaneous SSc (dcSSc), 18 had limited cutaneous SSc (lcSSc) and four were unclassified. Overall, 56% had pulmonary fibrosis, 37% had myositis and 98% were antinuclear antibody (ANA) positive, with a notable absence of anti-centromere antibodies. Subset comparisons showed myositis and a reduced forced vital capacity to be significantly more common with dcSSc than lcSSc. The only significant sex differences were that arthralgia/arthritis was more common in women, while calcinosis occurred more frequently in men. Seven of the eight known deaths occurred in patients with dcSSc. These findings, particularly the age of disease onset, predominance of the dcSSc subset, inflammatory features of myositis and a raised erythrocyte sedimentation rate, and absence of anti-centromere antibodies, are similar to those reported previously in African-Americans.

[Clinical course of idiopathic inflammatory myopathies: complications, survival and prognostic factors]

OBJECTIVES

To describe the clinical and epidemiological characteristics, complications, survival and prognostic factors of a series of patients with idiopathic inflammatory myopathy (IIM) diagnosed with homogeneous criteria in the same center.

PATIENTS AND METHODS

Patients with the diagnosis of IIM during an inclusion period of 20 years were studied. They were classified following the criteria of Bohan and Peter, and Dalakas. Epidemiological, clinical and therapeutical data were obtained in all cases. Evolution and survival were analyzed with the Kaplan-Meier and Cox multiple regression models.

RESULTS

One-hundred thirty-five patients with IIM were included in the study: 32 polymyositis (PM), 90 dermatomyositis (DM) and 13 inclusion body myositis (IBM). Forty-six percent presented some complications attributed to the disease or treatment, and 10 with PM, 29 with DM and 3 with IBM died during the follow-up. The probabilities of survival were 86% the first year, 80% the second year, 71% the fifth year, and 57% the tenth year. Infections and cancer were the main death causes. While survival analyses did not show independent risk factors for PM, advanced age, presence of associated neoplasm, raised erythrocyte sedimentation rate (ESR) and muscle relapse were identified as a poor prognostic indicators for DM, whereas raised ESR and long lasting symptoms prior to diagnosis of the myopathy were for IBM.

CONCLUSION

In spite of the therapeutic advances, IIM are still diseases with high mortality and morbidity.

[Tropical myositis]

Tropical pyomyositis (TP) is a microbial infection involving one or more skeletal muscles that rapidly leads to abscess. The most common infectious agent is Staphylococcus aureus. Since muscle tissue is highly resistant to infection, occurrence of TP is contingent upon one or more compromising factors such as trauma, skin lesions, parasitosis, or malnutrition. HIV infection is currently a major factor in the occurrence of TP. While Staphylococcus aureus accounts for 80% of cases, other microbial agents have been identified including gram-positive cocci and gram-negative bacilli. TP is endemic in intertropical zones of Africa and Latin America and in island areas of the Pacific Ocean. However a growing number of non-tropical cases have been reported in association with AIDS. The most frequent presentation is single-muscle involvement in the thighs, calves, and buttocks. The symptomatic phase or suppurative phase is almost always associated with hyperthermia. The infected muscle indurates prior to development of characteristic fluctuance. Hemocultures are seldom positive but needle aspiration may confirm diagnosis. Ultrasound imaging can allow early detection. Severe sepsis or cardiovascular, renal, or pleuropulmonary complications are observed in 10% of cases. Treatment is antibiotic therapy with penicillin M and surgical drainage or needle puncture of abscess cavities. Prognosis is generally favorable even in HIV-infected patients.

Soft tissue and muscular infections (including group A streptococci)

Skin, soft tissue and muscular infections are very common and can progress to induce serious life-threatening local and systemic complications. They often occur in sites that have been compromised or injured by foreign bodies, trauma, ischaemia, malignancy or surgery. In addition to group A streptococci and Staphylococcus aureus, the indigenous local microflora is usually responsible for these infections. Anatomical sites that are subject to faecal or oral contamination are particularly at risk. The early recognition and proper medical and surgical management of these infections are of primary importance.