Sleep apnea in adult myotonic dystrophy patients who have no excessive daytime sleepiness.

Department of Pulmonary Diseases, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Sleep And Breathing (Impact Factor: 2.26). 05/2009; 14(1):19-24. DOI: 10.1007/s11325-009-0270-6
Source: PubMed

ABSTRACT Sleep apnea is common in myotonic dystrophy (MD) and may cause respiratory failure. Most of the sleep studies have been performed in patients with excessive daytime sleepiness (EDS), which is a characteristic and strong predictor of sleep apnea. Therefore, we investigated the prevalence of sleep apnea in adult MD patients who have no EDS.
Epworth Sleepiness Scale was used to exclude EDS and a score over 10 was accepted as an indicator of EDS. Sleep studies of 17 adult MD patients with the Epworth sleepiness scale score < or =10 were retrospectively reviewed. Spirometry (n = 16) and daytime arterial blood gasses were used to evaluate the relationship with nocturnal parameters.
On admission to the outpatient chest clinic, seven patients had normal spirometry, and ten had daytime hypercapnia and/or hypoxemia. All but one had sleep apnea (apnea-hypopnea index > or =5 events/h of sleep; mild in five, moderate in seven, and severe in four). Hypopneas were more common than apneas (16.9 +/- 13.2 events/h vs. 4.6 +/- 4.1 events/h). Nocturnal desaturation episodes were very frequent (oxygen desaturation index, 19.7 +/- 20.3/h of sleep). Three patients had central sleep apnea and 13 had obstructive sleep apnea. Body mass index, spirometry parameters (FVC and FEV1) and arterial oxygen tension were moderately correlated with nocturnal oxygenation parameters. Apnea-hypopnea index showed moderate correlation with spirometry parameters (FVC and FEV1).
Sleep apnea and oxygen desaturations are very common in MD patients who report no excessive daytime sleepiness. Daytime lung function parameters are not sufficiently reliable for screening sleep apnea. Therefore, we recommend routine polysomnography in MD patients.

1 Bookmark
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Myotonic dystrophy types 1 (DM1) and 2 (DM2) are the most common muscular dystrophies in adulthood. A high prevalence of excessive daytime sleepiness (EDS) and sleep disordered breathing was documented in DM1; however, there are limited data available regarding DM2. Goals of the study were: (1) to evaluate the prevalence of sleep apnea in a large cohort of patients (71 DM1 and 14 DM2) and (2) to analyze correlations among such disorders and clinical features of myotonic dystrophies. All patients underwent clinical examination, subjective sleep evaluation, and home based cardiorespiratory monitoring, and most of them performed pulmonary function tests and oropharyngeal-oesophageal scintigraphy (OPES). Almost 45 % of patients reported poor sleep quality; only 20 % of them referred EDS. Sleep studies documented sleep apnea, mostly obstructive, in 69 % DM1 patients and 43 % DM2 patients; overall, 28 % of cases needed non-invasive ventilation. Neither age, gender, illness duration, body mass index, muscle involvement, OPES respiratory function indexes, nor n(CTG) in leukocytes were predictive of sleep apnea in DM1 patients. Conversely, in DM1 the central apnea-hypopnea index is correlated with the oral transit time estimated by OPES, whereas in DM2 apnea indexes are correlated with pulmonary function parameters. Sleep apnea is highly prevalent in both forms of myotonic dystrophies. In DM1, no clinical parameters appear to be predictive, while age appears to influence the severity of the obstructive variant; in DM2, the severity of sleep apnea is correlated with the degree of respiratory muscle involvement. Considering the harmful consequences of sleep apnea on cardiorespiratory function, our findings suggest including PSG in the follow-up of myotonic dystrophies.
    Sleep And Breathing 12/2013; · 2.26 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Myotonic dystrophy type 1 (DM1) represents the 1 chronic neuromuscular disease with the most prominent sleep disorders, including excessive daytime sleepiness (EDS), sleep apneas, periodic leg movements during sleep, and rapid eye movement sleep dysregulation. The large majority of DM1 patients complain about EDS, which may have a deleterious impact on work, domestic responsibilities, social life, and quality of life. Here, we review the extant literature and report that studies are largely supportive of the view that DM1-related EDS is primarily caused by a central dysfunction of sleep regulation rather than by sleep-related disordered breathing (SRDB) or sleep fragmentation. The pathogenesis of EDS in DM1 still remains unclear but several arguments favor a model in which brain/brainstem nuclear accumulations of toxic expanded DM protein kinase (DMPK) gene are responsible for aberrant genes expression in modifying alternative splicing. Regarding management, early recognition, and treatment of SRDB with nocturnal noninvasive mechanical ventilation is first mandatory. However, despite its appropriate management, EDS often persists and may require a psychostimulant but no consensus has been yet established. Further studies are needed to clarify the discrepancies between daytime sleepiness/fatigue complaints and subjective/objective measurement of daytime sleepiness, the role of cognitive impairment and apathy in this relationship, and its reversibility with appropriate management.
    Current Neurology and Neuroscience Reports 04/2013; 13(4):340. · 3.78 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Myotonic dystrophy is the most common type of muscular dystrophy in adults and is characterized by progressive myopathy, myotonia, and multiorgan involvement. Two genetically distinct entities have been identified, myotonic dystrophy type 1 (DM1 or Steinert’s Disease) and myotonic dystrophy type 2 (DM2). Myotonic dystrophies are strongly associated with sleep dysfunction. Sleep disturbances in DM1 are common and include sleep-disordered breathing (SDB), periodic limb movements (PLMS), central hypersomnia, REM sleep dysregulation (high REM density and narcoleptic-like phenotype). Interestingly, drowsiness in DM1 seems to be due to a central dysfunction of sleep-wake regulation more than SDB. To date, little is known regarding the occurrence of sleep disorders in DM2. SDB (obstructive and central apnoea), REM sleep without atonia and restless legs syndrome have been described. Further polysomnographic, controlled studies are strongly needed, particularly in DM2, in order to clarify the role of sleep disorders in the myotonic dystrophies.
    journal of neurodegenerative diseases. 08/2013;