Correlation of electromyogram and muscle biopsy in myopathy of young age.

OBJECTIVE: To investigate the accuracy of electromyogram (EMG) compared to muscle biopsy in young myopathic patients. DESIGN: Observational study. SETTING: A university rehabilitation hospital. PARTICIPANTS: Cases (N=62) were included if the patient was 18 years or younger, and if data were available from muscle biopsy, EMG, and final clinical diagnosis. INTERVENTION: No intervention. MAIN OUTCOME MEASURE: Sensitivity of EMG. RESULTS: EMG showed myopathic findings in 55 patients, and microscopy revealed myopathy in 50 patients and nonspecific findings in 5 patients. Twenty-eight out of 33 patients showed myogenic EMG findings with a conventional EMG, and histology revealed myopathy in 24 patients. In comparison, turns/amplitude analysis (TAA) with a conventional EMG detected myogenic findings in 27 of 29 patients. Twenty-six of these 27 patients showed myogenic findings in the biopsy. CONCLUSIONS: We concluded that EMG is useful for the detection of myopathy in young patients. In addition, TAA may be helpful in cases of no definite conventional EMG findings and less cooperative patients.

Quality of life for primary caregivers of muscular dystrophy patients in South Korea.

BACKGROUND: Although some studies measured the burden of caregivers and the factors that influenced their feelings of burden, few studies have measured the quality of life (QOL) for primary caregivers of patients with muscular dystrophy (MD). We assessed the QOL for primary caregivers of patients with MD in South Korea and identified factors associated with caregivers' QOL. METHODS: Ninety dyads of patients with MD and their primary caregivers were enrolled in this study. The QOL of caregivers of patients with MD was assessed subjectively using the World Health Organization Quality of Life Assessment, Life Brief Form. Caregivers' emotional status was assessed using the Beck Depression Inventory (BDI) and family function level was evaluated using the Family APGAR scale. Patients reported their emotional status using the BDI or the Children's Depression Inventory. The functional levels of patients were evaluated by the modified Barthel Index. RESULTS: Caregivers' QOL was statistically associated with family income, family function, emotional status of patients, level of education, and emotional status of caregivers (P < 0.05). Caregivers who were employed had a significantly higher QOL than those who were not (P < 0.05). In multiple regression analyses, emotional and employment status of caregivers was strongly associated with caregivers' QOL. CONCLUSION: Rehabilitation teams should consider not only the physical factors of patients but also the psychological and demographic factors of primary caregivers of patients with MD.

A comparative study of magnetic-activated cell sorting, cytotoxicity and preplating for the purification of human myoblasts.

Although cultured myoblast transplantation has been extensively studied as a gene complementation approach to muscular dystrophy treatment, clinical success has still been limited. The inability to adequately isolate and purify myoblasts presents a major limitation to the production of sufficient myoblasts for engrafting purposes. This study attempted to purify myoblasts from primary culture by magnetic-activated cell sorting (MACS), complement-mediated cytotoxicity, and a preplating technique. As a result of positive myoblasts selection by MACS, the average percentage of myoblasts in mixed culture was increased from 30.0% to 41.7%. We observed both myoblast lysis and fibroblast lysis after complement-mediated cytotoxicity. Enrichment of myoblasts in mixed culture was found to increase to 83.1% by using the preplating technique. In addition, higher purification (92.8%) was achieved by following the preplating technique with MACS. Thus, preplating in combination with magnetic-activated cell sorting allows for a rapid and effective isolation of myoblasts from human muscle tissue.

Respiratory muscle strength and cough capacity in patients with Duchenne muscular dystrophy.

The function of inspiratory muscles is crucial for effective cough as well as expiratory muscles in patients with Duchenne muscular dystrophy (DMD). However, there is no report on the correlation between cough and inspiratory muscle strength. To investigate the relationships of voluntary cough capacity, assisted cough techniques, and inspiratory muscle strength as well as expiratory muscle strength in patients with DMD (n= 32). The vital capacity (VC), maximum insufflation capacity (MIC), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) were measured. Unassisted peak cough flow (UPCF) and three different techniques of assisted PCF were evaluated. The mean value of MICs (1918 +/- 586 mL) was higher than that of VCs (1474 +/- 632 mL) (p < 0.001). All three assisted cough methods showed significantly higher value than unassisted method (212 +/- 52 L/min) (F = 66.13, p < 0.001). Combined assisted cough technique (both manual and volume assisted PCF; 286 +/- 41 L/min) significantly exceeded manual assisted PCF (MPCF; 246 +/- 49 L/ min) and volume assisted PCF (VPCF; 252 +/- 45 L/min) (F = 66.13, p < 0.001). MIP (34 +/- 13 cmH2O) correlated significantly with both UPCF and all three assisted PCFs as well as MEP (27 +/- 10 cmH2O) (p < 0.001). Both MEP and MIP, which are the markers of respiratory muscle weakness, should be taken into account in the study of cough effectiveness.

Assisted cough and pulmonary compliance in patients with Duchenne muscular dystrophy.

The aim of this study was to investigate the factors affecting cough ability, and to compare the assisted cough methods in patients with Duchenne muscular dystrophy (DMD). A total seventy-one male patients with DMD were included in the study. The vital capacity (VC) and maximum insufflation capacity (MIC) were measured. The unassisted peak cough flow (UPCF) and three different techniques of assisted peak cough flow were evaluated. UPCF measurements were possible for all 71 subjects. But when performing the three different assisted cough techniques, peak cough flows (PCFs) could be obtained from only 51 subjects. The mean value of MICs (1801 +/- 780 cc) was higher than that of VCs (1502 +/- 765 cc) (p< 0.01). All three assisted cough methods showed a significantly higher value than the unassisted method (F=80.92, p< 0.01). The manual assisted PCF under MIC (MPCFmic) significantly exceeded those produced by manual assisted PCF (MPCF) or PCF under MIC (PCFmic). The positive correlation between the MIC, VC difference (MIC-VC), and the difference between PCFmic and UPCF (PCFmic-UPCF) was seen (r=0.572, p< 0.01). The preservation of pulmonary compliance is important for the development of an effective cough as well as assisting the compression and expulsive phases. Thus, the clinical importance of the inspiratory phase and pulmonary compliance in assisting a cough should be emphasized.