Shun-Sheng Chen

Development and validation of a muscular dystrophy-specific functional rating scale

Objective: To develop a reliable and valid new rating scale for measuring the functional impact of muscular dystrophy. Design: Prospective and longitudinal investigation. Setting: Three academic medical centres in Taiwan and the Muscular Dystrophy Association of Taiwan. Measures: The Brooke Scale, the Vignos Scale, the Barthel Index, muscular strength, contracture severity, and predicted forced vital capacity (FVC%). Methods: Scale development was in three stages. In stage I, a preliminary pool of 53 items was generated from patient interviews (n-/25), literature review, existing functional rating scales and expert opinion. In stage II, these items were administered to 85 patients with muscular dystrophy. The resulting data were analysed to construct a rating scale (the Muscular Dystrophy Functional Rating Scale, MDFRS) that encompassed four unidimensional constructs: mobility, basic activities of daily living, arm function and impairment. In stage III, the measurement properties of this rating scale were assessed in 121 muscular dystrophy patients different from those examined with the preliminary instrument. Results: Internal consistency reliability was excellent for all domains of the final 33-item scale, with values of Cronbach’s alpha ranging from 0.84 to 0.97. Intraclass correlation coefficients for test-retest and inter-rater reliability were 0.99 for all domains of the MDFRS. The MDFRS showed moderate to high correlations with a range of functional rating scales measuring similar aspects and impairment parameters (Spearman’s rho=0.65-0.91; P<0.001, each). Confirmatory factor analysis supported a unitary construct of the four-dimensional MDFRS. The MDFRS had small floor and ceiling effects in the study samples. Sensitivity to change was confirmed by large standardized response means for the MDFRS total score. Conclusions: The MDFRS is a reliable and valid disease-specific measure of functional status for patients with muscular dystrophy.

Knee Isokinetic Strength and Body Fat Analysis in University Students

Many factors such as anthropometric variables influence strength performance. This study is to determine the relationship between knee isokinetic strength and body composition, and to compare the gender differences. Test-retest reliability had been performed within one week for all measurement methods before the formal study. Fifty-eight 20-25 year-old university students, 32 females and 26 males, participated in this study. Isokinetic strength of the knee flexion and extension was measured at two angular velocities of 60 degrees/sec and 120 degrees/sec. Body composition was measured by bioelectrical impedance analysis (BIA) and skinfold caliper. The others variables including height, body weight, body mass index (BMI), and waist to hip ratio were measured or calculated. The results showed that the intra-class correlation coefficients for isokinetic knee strength were between 0.83 and 0.93, and body composition and anthropometric variables were between 0.83 and 0.98. Isokinetic knee strength was significantly correlated with body height, body weight, BMI, waist and hip ratio and percent of body fat estimated by skinfold caliper (r = -0.56 to 0.64). The correlation between isokinetic strength with percent of body fat estimated by BIA (r = -0.60 to -0.74; p < 0.001) and with fat free mass (r = 0.64 to 0.78; p < 0.001) was even higher. Although male subjects had significantly greater mean values in body height, body weight, waist to hip ratio and isokinetic strength than female subjects, the MANCOVA showed that the effect of gender on knee isokinetic strength would be eliminated when the covariant variable, the percent of body fat measured by BIA and BMI was controlled in the analysis model. In conclusion, knee isokinetic strength was significantly negatively correlated with proportion of fat and positively correlated with fat free mass. The magnitude of strength difference between males and females could be explained by differences in body fat proportion and BMI in this study. Therapist would take the body fat composition, fat free mass, and BMI into consideration in knee muscle strength measurement. Less body fat and higher BMI will contain more fat free mass that produces more muscle strength.

Strength and Functional Performane of Patients with Limb-Girdle Muscular Dystrophy

This study was design to reach a better understanding of muscle strength, motor function and activity of daily living in patients of limb-girdle muscular dystrophy. Forty-eight patients diagnosed as cases of limb-girdle muscular dystrophy were included in this study. Manual muscle testing was used to evaluate muscle strength. The Brooke and Vignos scales were used to grade upper and lower extremities function, respectively, and the ability of daily living activity was measured by Barthel index. Our patients showed progressive symmetrical limb-girdle muscular weakness. Upon regression analysis we found that mean muscle strength was inversely related to disease duration (years) as follows: mean muscle strength = 0.6052 + (0.6309/disease duration). According to the Brooke functional scale, 89.6% of our patients were graded as 1-3 and 10.4% were graded as 5. On the Vignos functional scale, 79.1% of patients fell into the grades 1-5, one person (2.1%) in grade 6 and 18.8% in grade 9 category. The average Barthel index was 85.3 +/- 20.7. Mean muscle strength was significantly correlated with the average Barthel, Vignos and Brooke functional scales. Our study could offer the strength and functional performance of limb-girdle muscular dystrophy on natural history. The muscle strength declined in Taiwanese patients of limb-girdle muscular dystrophy in a typical pattern. Regression analysis showed that the strength was inversely related to disease duration. These findings demonstrate that most of our patients suffered from mild or moderate physical disability.

The Strength and Functional Performance in Patients With Facioscapulohumeral Muscular Dystrophy

Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive myopathy with autosomal dominant inheritance remarkable for its early involvement of facial musculature. The purpose of our study was to assess the rate of strength deterioration, functional condition and performance of activity of daily living of patients with FSHD in Taiwan. Twenty patients diagnosed with FSHD were included in this study. Manual muscle testing (MMT) was used to evaluate muscle strength. The Brooke and Vignos scales were used to assess upper and lower extremity function respectively, and the capability of the activity of daily living was measured by Barthel index. The result of the strength testing was characterized by the presence of a progressive asymmetrical muscular weakness in patients with FSHD. The mean muscular strength of the right extremity was weaker than its left counterparts (p < 0.05) and the shoulder muscle group was the weakest. According to the Brooke functional scale, 20% of our patients were graded as 1, 30% as grade 2, and 50% as grade 3. On the Vignos functional scale, 50% of patients fell into grade 1, 10% in grade 2, and 40% in grades 3-5. Vignos scale was significantly correlated with mean muscle strength (p < 0.05). The average value of Barthel index was 97.8 +/- 4.7. The muscle strength decline in this Taiwanese of FSHD population was more severe in shoulder girdle area. The mean muscle strength of the right extremity was weaker than the left. Most of our patients suffered from mild or moderate physical disability. Finding of these Taiwanese FSHD population is similar to those reported elsewhere in the world.

Quality of life of patients with Duchenne muscular dystrophy: from adolescence to young men

Abstract Purpose: This study investigated quality of life (QOL) in adolescent and young men with Duchenne muscular dystrophy (DMD). Methods: Health-related QOL and global QOL were assessed with the Short Form 36 (SF-36) and World Health Organization Quality of Life-BREF (WHOQOL-BREF). Associations between functional status and QOL were assessed. Results: All domains of the SF-36 were below Taiwan norms (effect size: −14.2 to −0.5), especially Physical Function, Role Physical, and Social Function. Three of the four domains of the WHOQOL-BREF were below Taiwan norms (effect size: −2.0 to −0.7). The Physical Function of the SF-36 was moderately correlated with functional status (mobility, basic activities of daily living, and arm function). The Social Function of the SF-36 and Social Relationships of the WHOQOL-BREF were also moderately correlated with functional status (impairment, basic activities of daily living, and arm function). Conclusion: The adolescent and young men with DMD had poor health-related and global QOL. Poor QOL was related to both physical condition and social health. We suggest that rehabilitation programs focus on using assistive devices to facilitate arm function and encouraging participation in social activities to improve the QOL of patients with DMD. Implications for rehabilitation Duchenne muscular dystrophy (DMD) is a progressive muscle weakness disease that not only impacts physical health but also leads to poor quality of life in many domains. A valuable rehabilitation goal for patients with DMD is to encourage participation in social activities. Medical care and educational programs should plan a formal transition processes for patients with DMD from pediatric to adult care to maximum their quality of life. Arm function is associated with many domains of global quality of life, so a key element in improving quality of life may be to improve arm function.

Factors affecting the health-related quality of life of caregivers of patients with muscular dystrophy

Muscular dystrophy (MD) is a group of progressive muscle weakness diseases. The caregiver burden, increasing as the disease progresses, can be associated with impaired health-related quality of life (HRQOL). The aims of this study were to investigate the HRQOL in caregivers of patients with MD and identify the factors associated with HRQOL. A cross-sectional assessment of caregiver HRQOL was performed with the Short Form-36 and compared with norms. The factors affecting HRQOL were investigated by patient and caregiver characteristics. The Muscular Dystrophy Functional Rating Scale was used to assess the functional status (mobility, basic activities of daily living, arm function, and impairment) of patients. The demographic data and social interaction activities of caregivers were assessed. Caregivers (n = 62) had poor HRQOL. Caregiver HRQOL was associated with the patient’s functional status, especially in the domains of Vitality and Mental Health. Numerous visits by neighbors and close friends of the caregiver family indicated better HRQOL (in the body pain, general health, vitality, role emotion and mental health domains). Caregiver HRQOL was associated with caregiver education level, while patient age, caregiver age, length of caregiving, and family income were not. These findings demonstrate that caregivers have poor HRQOL, and the mental domain of quality of life is associated with the patient’s functional status, social interaction, and caregiver education level. We suggest that rehabilitation programs focus on caregiver HRQOL, promote the patient’s functional status with assistive technology, enhance professional caring techniques, and encourage participation in social groups to improve caregiver HRQOL.