Scoliosis in patients with Duchenne muscular dystrophy

[Spinal deformity in Duchenne muscular dystrophy]

Boys with Duchenne muscular dystrophy develop scoliosis in 95% of cases. Conservative management to avoid progression of the deformity is not successful. However, treatment with corticosteroids may avoid the onset of scoliosis in some patients. Early surgical treatment and spine fusion is usually recommended before severe cardiopulmonary symptoms have developed. With modern surgical techniques, the sitting ability and quality of life can be preserved with a moderate complication rate. An interdisciplinary approach is mandatory to achieve these goals.

Surgical treatment of scoliosis in Ullrich Congenital Muscular Dystrophy: a case series of 3 patients

Scoliosis in Ullrich Congenital Muscular Dystrophy (UCMD) is very common, with a reported incidence of more than 50%, and it is rapidly progressive. There are no previous studies which specifically focus on scoliosis surgery in UCMD patients. This article reports three cases of scoliosis surgery in UCMD, focusing on operative course, clinical and radiological results achieved, fusion area and complications, with a 2-year follow-up. The surgical technique adopted for vertebral arthrodesis included: high-density pedicle screw systems, asymmetric rods contouring and direct vertebral rotation. The summary results shown a significative correction of the coronal deformity, with a reduction of the mean Cobb angle from 49° to 25° post-operatively. Mean pelvic tilt remained stable, while L5-tilt showed a decrease from 10° to 6°. Mean screw density was 1.92. None of the patients required extended fixation to S2. No major complications were reported, and patients maintained their pre-operative walking ability. All the patients reported a subjective improvement in quality of life, with a better sitting comfort. In conclusion, posterior spinal fusion with high-density pedicle screw systems and direct vertebral rotation may be safe and effective in surgical correction of scoliosis in UCMD. If pelvic obliquity and L5-tilt are less than 15°, could be possible to achieve an optimal spinal and pelvic balance even without sacral or pelvic fixation.

The relationship between scoliosis and upper extremity functions in patients with Duchenne muscular dystrophy

Objectives

The aim of this study was to investigate the relationship between scoliosis and upper extremity functions in patients with Duchenne muscular dystrophy (DMD).

Patients and methods

Between January 2018 and July 2018, a total of 55 patients (54 males, 1 female; mean age: 9.9±2.9 years; range, 6 to 15 years) who were diagnosed with DMD based on the clinical, laboratory, muscle biopsy and molecular analysis results were included in this cross-sectional study. Scoliosis was evaluated and Cobb angles were measured. Functional Ambulation Scale and Brooke and Vignos scale scores were recorded. The ABILHAND-Kids questionnaire and Nine-Hole Peg Test (9-HPT) were used to assess the upper extremity functions. Hand grip strengths were also evaluated.

Results

The median ABILHAND-Kids scores and the hand grip strength values of the patients without scoliosis were significantly higher compared to those with scoliosis (p=0.002 and p=0.004 for right hand and p=0.012 for left hand, respectively). There was no statistically significant difference in the 9-HPT scores between the patients with and without scoliosis (p>0.05). We found a negative, significant correlation between the Cobb angle and ABILHAND-Kids scores in patients with scoliosis (r=-0.503; p=0.017).

Conclusion

Our study results show a moderate relationship between scoliosis and upper extremity functions. Scoliosis may adversely affect upper extremity functions in patients with DMD.

Duchenne muscular dystrophy: the management of scoliosis

This study summaries the current management of scoliosis in patients with Duchenne Muscular Dystrophy. A literature review of Medline was performed and the collected articles critically appraised. This literature is discussed to give an overview of the current management of scoliosis within Duchenne Muscular Dystrophy. Importantly, improvements in respiratory care, the use of steroids and improving surgical techniques have allowed patients to maintain quality of life and improved life expectancy in this patient group.

Galectin-1 Protein Therapy Prevents Pathology and Improves Muscle Function in the mdx Mouse Model of Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a fatal neuromuscular disease caused by mutations in the dystrophin gene, leading to the loss of a critical component of the sarcolemmal dystrophin glycoprotein complex. Galectin-1 is a small 14 kDa protein normally found in skeletal muscle and has been shown to be a modifier of immune response, muscle repair, and apoptosis. Galectin-1 levels are elevated in the muscle of mouse and dog models of DMD. Together, these findings led us to hypothesize that Galectin-1 may serve as a modifier of disease progression in DMD. To test this hypothesis, recombinant mouse Galectin-1 was produced and used to treat myogenic cells and the mdx mouse model of DMD. Here we show that intramuscular and intraperitoneal injections of Galectin-1 into mdx mice prevented pathology and improved muscle function in skeletal muscle. These improvements were a result of enhanced sarcolemmal stability mediated by elevated utrophin and α7β1 integrin protein levels. Together our results demonstrate for the first time that Galectin-1 may serve as an exciting new protein therapeutic for the treatment of DMD.

Sibling concordance for clinical features of Duchenne and Becker muscular dystrophies

INTRODUCTION

The correlation of markers of disease severity among brothers with Duchenne or Becker muscular dystrophy has implications for clinical guidance and clinical trials.

METHODS

Sibling pairs with Duchenne or Becker muscular dystrophy (n = 60) were compared for ages when they reached clinical milestones of disease progression, including ceased ambulation, scoliosis of ≥ 20°, and development of cardiomyopathy.

RESULTS

The median age at which younger brothers reached each milestone, compared with their older brothers ranged from 25 months younger for development of cardiomyopathy to 2 months older for ceased ambulation. For each additional month of ambulation by the older brother, the hazard of ceased ambulation by the younger brother decreased by 4%.

CONCLUSIONS

The ages when siblings reach clinical milestones of disease vary widely between siblings. However, the time to ceased ambulation for older brothers predicts the time to ceased ambulation for their younger brothers.

Use of imatinib in the prevention of heterotopic ossification

BACKGROUND

Heterotopic ossification (HO) is a common complication following orthopedic and trauma surgery, which may have substantial negative effects on the postoperative outcome. Angiogenesis appears to play a critical role in heterotopic ossification. One of the involved signaling molecules is platelet-derived growth factor (PDGF) which may be inhibited by imatinib.

QUESTIONS/PURPOSES

Our goal was to prevent HO by pharmacologically interfering with the molecular signaling pathways involved in the developmental process. We hypothesized that by administering a proven inhibitor of PDGF expression, heterotopic bone formation may be prevented.

METHODS

The effect of imatinib on HO formation was studied in a murine model which reliably produces islets of HO within the soft tissue following Achilles tenotomy. The control group underwent Achilles tenotomy only. The imatinib group received imatinib mesylate. After trial completion, the limbs were harvested and scanned by micro-CT. Heterotopic bone volume was then identified and quantified.

RESULTS

The mean volume of heterotopic bone formed in the control group was 0.976mm(3) compared to 0.221 mm(3) in the imatinib group. The volume of HO in the treatment group was reduced by 85% compared to the control group.

CONCLUSIONS

The administration of imatinib was associated with a significantly reduced volume of HO. This may be due to the inhibitory effect of imatinib on the PDGF signaling pathway during development of HO.

CLINICAL RELEVANCE

The successful reduction of HO formation following imatinib administration has led to further insight concerning the pathogenesis of HO which in the future may lead to new clinical approaches towards the prevention of HO.

Dystrophin and utrophin "double knockout" dystrophic mice exhibit a spectrum of degenerative musculoskeletal abnormalities

Duchenne muscular dystrophy (DMD) is a degenerative muscle disorder characterized by the lack of dystrophin expression at the sarcolemma of muscle fibers. In addition, DMD patients acquire osteopenia, fragility fractures, and scoliosis indicating that a deficiency in skeletal homeostasis coexists but little is known about the effects of DMD on bone and other connective tissues within the musculoskeletal system. Recent evidence has emerged implicating adult stem cell dysfunction in DMD myopathogenesis. Given the common mesenchymal origin of muscle and bone, we sought to investigate bone and other musculoskeletal tissues in a DMD mouse model. Here, we report that dystrophin-utrophin double knockout (dko) mice exhibit a spectrum of degenerative changes, outside skeletal muscle, in bone, articular cartilage, and intervertebral discs, in addition to reduced lifespan, muscle degeneration, spinal deformity, and cardiomyopathy previously reported. We also report these mice to have a reduced capacity for bone healing and exhibit spontaneous heterotopic ossification in the hind limb muscles. Therefore, we propose the dko mouse as a model for premature musculoskeletal aging and posit that a similar phenomenon may occur in patients with DMD.

The correlation analysis of functional factors and age with duchenne muscular dystrophy

Objective

To correlate existing evaluation tools with clinical information on Duchenne muscular dystrophy (DMD) patients following age and to investigate genetic mutation and its relationship with clinical function.

Method

The medical records of 121 children with DMD who had visited the pediatric rehabilitation clinic from 2006 to 2009 were reviewed. The mean patient age was 9.9±3.4 years and all subjects were male. Collected data included Brooke scale, Vignos scale, bilateral shoulder abductor and knee extensor muscles power, passive range of motion (PROM) of ankle dorsi-flexion, angle of scoliosis, peak cough flow (PCF), fractional shortening (FS), genetic abnormalities, and use of steroid.

Results

The Brooke and Vignos scales were linearly increased with age (Brooke (y₁), Vignos (y₂), age (x), y₁=0.345x-1.221, R_Brooke²=0.435, y₂=0.813x-3.079, R_Vignos²=0.558, p<0.001). In relation to the PROM of ankle dorsi-flexion, there was a linear decrease in both ankles (right and left R²=0.364, 0.372, p<0.001). Muscle power, Cobb angle, PCF, and FS showed diversity in their degrees, irrespective of age. The genetic test for dystrophin identified exon deletions in 58.0% (69/119), duplications in 9.2% (11/119), and no deletions or duplications in 32.8% (39/119). Statistically, the genetic abnormalities and use of steroid were not definitely associated with functional scale.

Conclusion

The Brooke scale, Vignos scale and PROM of ankle dorsi-flexion were partially available to assess DMD patients. However, this study demonstrates the limitations of preexisting scales and clinical parameters incomprehensively reflecting functional changes of DMD patients.

Insights into bone health in Duchenne muscular dystrophy

Poor bone health is a significant problem for patients with Duchenne muscular dystrophy (DMD), a progressive, disabling disease. Although the primary focus of DMD disease pathogenesis is degeneration of striated muscle, impairment of bone health likely has a role in the disease that has only been superficially examined to date. Deficiency of bone mineral density and increased incidence of bone fractures are well-recognized clinical components of the DMD phenotype. Furthermore, therapy with corticosteroids, an approved treatment for DMD that prolongs ambulation, may have multiple effects on bone health in DMD patients. This review examines the evidence in preclinical models and in human DMD disease that provides insight into the role performed by bone in the disease pathogenesis and phenotype of DMD. The information reviewed here points toward the need for mechanistic and therapeutic studies to optimize bone health in DMD patients.

The natural history of cardiac and pulmonary function decline in patients with duchenne muscular dystrophy

STUDY DESIGN

Retrospective review of scoliosis progression, pulmonary and cardiac function in a series of patients with Duchenne Muscular Dystrophy (DMD).

OBJECTIVE

To determine whether operative treatment of scoliosis decreases the rate of pulmonary function loss in patients with DMD.

SUMMARY OF BACKGROUND DATA

It is generally accepted that surgical intervention should be undertaken in DMD scoliosis once curve sizes reach 35° to allow intervention before critical respiratory decline has occurred. There are conflicting reports, however, regarding the effect of scoliosis stabilization on the rate of pulmonary function decline when compared to nonoperative cohorts.

METHODS

We reviewed spinal radiographs, echocardiograms, and spirometry, hospital, and operative records of all patients seen at our tertiary referral center from July 1, 1992 to June 1, 2007. Data were recorded to Microsoft Excel (Microsoft, Redmond, WA) and analyzed with SAS (SAS Institute, Cary, NC) and R statistical processing software (www.r-project.org).

RESULTS

The percent predicted forced vital capacity (PPFVC) decreased 5% per year before operation. The mean PPFVC was 54% (SD = 21%) before operation with a mean postoperative PPFVC of 43% (SD = 14%). Surgical treatment was associated with a 12% decline in PPFVC independent of other treatment variables. PPFVC after operation declined at a rate of 1% per year and while this rate was lower, it was not significantly different than the rate of decline present before operation (P = 0.18). Cardiac function as measured by left ventricular fractional shortening declined at a rate of 1% per year with most individuals exhibiting a left ventricular fractional shortening rate of more than 30 before operation.

CONCLUSION

Operative treatment of scoliosis in DMD using the Luque Galveston method was associated with a reduction of forced vital capacity related to operation. The rate of pulmonary function decline after operation was not significantly reduced when compared with the rate of preoperative forced vital capacity decline.

Comparison between Operated Muscular Dystrophy and Spinal Muscular Atrophy Patients in terms of Radiological, Pulmonary and Functional Outcomes

STUDY DESIGN

Retrospective comparative study.

PURPOSE

To study and compare the surgical outcomes of muscular dystrophy (MD) and spinal muscle atrophy (SMA).

OVERVIEW OF LITERATURE

There are few reports that have evaluated and compared the surgical outcomes of MD and SMA patients.

METHODS

The patients (n = 35) were divided into two groups: a MD group with 24 patients and a SMA group with 11 patients. The average follow-up period was 21 months. All patients were operated for scoliosis correction using posterior instrumentation and fusion. In the immediate postoperative period, all efforts were made to reduce the pulmonary complications using non-invasive positive pressure ventilation and a coughing assist devices. The patients were evaluated by radiograph in terms of the Cobb's angle, pelvic obliquity, T1 translation, thoracic kyphosis and lumbar lordosis. The pulmonary function and self-image satisfaction were also assessed.

RESULTS

There was a lower correction rate in the MD group (41.5%) than in the SMA group (48.3%), even though the curves were smaller in the MD group. The correction in the pelvic obliquity was significantly better in the SMA group (p = 0.03). The predicted vital capacity showed a 4% reduction in the MD group 1 year after surgery, while the SMA group showed a 10% reduction. The peak cough flow and end tidal PCO(2) did not deteriorate and were well maintained. The average score for the improvement in self-image satisfaction postoperatively was 3.96 and 4.64 for the MD and SMA groups, respectively. The total complication rate was 45.7%; 14.3% of which were respiratory-related.

CONCLUSIONS

Surgical intervention for MD and SMA may be performed safely in patients with a very low forced vital capacity (< 30%) through aggressive preoperative and postoperative rehabilitation efforts.

Scoliosis in pediatric patients: comorbid disorders and screening

Scoliosis is one of the most commonly encountered pediatric spinal deformities. Knowledge of comorbid disorders associated with scoliosis is required in order to rule out other serious conditions. A thorough knowledge of the clinical scenarios associated with each of these disorders will help guide the pediatric practitioner in their work-up of associated conditions and possible further referrals. The aim of this review is to discuss the comorbidities associated with scoliosis and review appropriate screening tools aiding diagnosis.

Electric powered wheelchairs for those with muscular dystrophy: problems of posture, pain and deformity

PURPOSE

To identify areas of difficulty encountered by a regional wheelchair service in providing Electric Powered Indoor/outdoor wheelchairs (EPIOCs) to those with muscular dystrophy (MD) in the early years of their provision--particularly posture, pain and deformity.

METHOD

Wheelchair service records of all users between April 1997 and March 2000 were reviewed retrospectively and issues relating to weakness, pain/discomfort, deformities, other medical issues, weight change, function, posture and driving were documented on a purpose-designed proforma. Adjustments and modifications were documented over the 2-year period following chair delivery.

RESULTS

Of 325 EPIOC users on the departmental database, 29 had MD (15 Duchenne's), whose users charts were reviewed. Almost 80% of users needed clinical review within 2 years, mostly due to a scoliosis. Other problems were postural (66%), medical (48%), pain (31%), functional (24%) and weight change (14%). The commonest prescriptions were for specialised seating (24%), lateral supports, headrests and footrests (21% each).

CONCLUSIONS

The rate of disease progression was not planned for by the service. Most clients were seen in response to deterioration, rather than anticipating it. Planned reviews within 1 year appear essential for teenagers with MD with the dual issues of rapid maturation and progressive disease.