A French retrospective study of the records of 149 adults with an average age of 46.5 years and suffering from myotonic dystrophy (45) , myasthenia (20), Pompe disease (9), spinal muscular atrophy (8), facioscapulohumeral myopathy (8), Duchenne myopathy (5), Becker myopathy (1) or another neuromuscular disease (53) explored by respiratory polygraphy, nocturnal transcutaneous capnography and blood gas, shows that:
- 109 had sleep disordered breathing ;
- 33% had isolated sleep apnea syndrome, most often of central origin;
- 25.7% had both sleep apnea and diurnal and/or nocturnal hypercapnia;
- half the patients with nocturnal hypercapnia had diurnal hypercapnia;
- 21.1% had diurnal hypercapnia without nocturnal hypercapnia.
In order to improve treatment, the authors advocate a diagnostic strategy for sleep-disordered breathing in slowly progressing myopathies combining respiratory polygraphy, nocturnal transcutaneous capnography and blood gases, since in their study :
- a capnia greater than 45 mmHg in blood gases alone would have identified only a quarter of sleep apnea syndromes;
- nocturnal transcutaneous capnography in the absence of nocturnal alveolar hypoventilation would have missed two-thirds of sleep apnea syndromes;
- the combination of the two types of examination would have led to a missed diagnosis of sleep apnea syndrome in 56% of cases.
