Identification of sleep hypoventilation in young individuals with Becker muscular dystrophy: A pilot study

Diagnosis and management of Becker muscular dystrophy: the French guidelines

Becker muscular dystrophy (BMD) is one of the most frequent among neuromuscular diseases, affecting approximately 1 in 18,000 male births. It is linked to a genetic mutation on the X chromosome. In contrast to Duchenne muscular dystrophy, for which improved care and management have changed the prognosis and life expectancy of patients, few guidelines have been published for management of BMD. Many clinicians are inexperienced in managing the complications of this disease. In France, a committee of experts from a wide range of disciplines met in 2019 to establish recommendations, with the goal of improving care of patients with BMD. Here, we present the tools to provide diagnosis of BMD as quickly as possible and for differential diagnoses. Then, we describe the multidisciplinary approach essential for optimum management of BMD. We give recommendations for the initial assessment and follow-up of the neurological, respiratory, cardiac, and orthopedic consequences of males who present with BMD. Finally, we describe the optimal therapeutic management of these complications. We also provide guidance on cardiac management for female carriers.

Respiratory Dysfunction in Becker Muscular Dystrophy Patients: A Case Series and Autopsy Report

BACKGROUND

Few studies have examined respiratory dysfunction in patients with Becker muscular dystrophy (BMD).

OBJECTIVE

This study aimed to examine the characteristics of respiratory dysfunction in patients with BMD.

METHODS

The present retrospective study assessed respiratory parameters of adult BMD patients using medical records and compared these parameters with various patient characteristics to identify correlations. BMD patients aged 17 years and older who had been diagnosed genetically and/or pathologically were included in the analysis.

RESULTS

Of the source population of 133 patients, respiratory function was assessed in 85. Two of these patients had no symptoms, and eight had died. Mean % forced vital capacity (% FVC) was 94.2+/-21.7% (median, 96.1%; range, 5.1-134.1%). In 16 (19%) of the 85 patients, % FVC was <80%. Of these, seven were non-ambulant. Age, ambulation, and cardiac function did not significantly differ between patients with or without respiratory dysfunction, whereas age at onset was significantly lower in patients with respiratory dysfunction (7.7+/-4.7 years vs. 14.4+/-11.9 years; p = 0.001). One non-ambulant patient was a continuous NPPV user, and one patient had been recommended NPPV use but refused. Autopsy of one patient revealed that the diaphragm and intercostal muscles were less affected than proximal skeletal muscles.

CONCLUSION

BMD patients are at risk of developing respiratory dysfunction due to dystrophic changes in respiratory muscles. Respiratory function should be carefully and periodically monitored in these patients.