Excessive daytime sleepiness in myotonic dystrophy

https://doi.org/10.1016/S0022-510X(99)00042-8Get rights and content

Abstract

The aim of the present study was to assess whether or not there is any correlation between magnetic resonance imaging (MRI) abnormalities and excessive daytime sleepiness (EDS) in a consecutive series of patients with myotonic dystrophy (MD). The influences of nocturnal breathing abnormalities and sleep morphology on EDS were also evaluated. Ten MD patients were studied by means of an all-night polysomnographic recording, the multiple sleep latency test (MSLT) and MRI. Diagnosis of MD was established on the basis of the clinical and electrophysiological evidence of myotonia as well as of the characteristic genetic pattern. No patient had respiratory failure. Polysomnography and MSLT were also evaluated in ten healthy age-matched controls under the same environmental conditions. The mean MSLT value was significantly lower in patients than in controls. Five of the ten patients were found to have pathological EDS. The quantitative sleep variables and the nocturnal apnoeas in these five patients were not significantly different from those of the patients without EDS. As two patients did not undergo MRI because of claustrophobia, the MRI data were considered in eight patients. Corpus callosum (CC) atrophy was detected in four patients, whereas three patients showed hyperintense areas in the white matter. No correlation was found between EDS and MRI indexes of subcortical atrophy as well as volume of the hyperintense areas. By contrast, a correlation was found between the MSLT value and the reduction in the anterior area of the CC. Our data suggest that CC atrophy might occur in MD patients, and that the size of the CC anterior area might be associated with EDS.

Introduction

Myotonic dystrophy (MD), the most common form of muscular dystrophy in adults, is a progressive multisystemic disorder that is inherited through an autosomal trait. Excessive daytime sleepiness (EDS) in patients with MD is common, and is a major factor that interferes with the social life of these patients. The possible explanations for EDS that have been put forward include dysfunction of central sleep regulation [1], [2], respiratory insufficiency [3], [4] and apnoea, particularly of the central type [5], [6].

Recent developments in imaging technology, especially magnetic resonance imaging (MRI), have enabled physicians to study the central nervous system (CNS) in patients with MD. Cerebral atrophy and white matter lesions are the most common abnormalities [7], [8], [9], [10], [11]. These CNS abnormalities have been correlated with clinical findings in MD patients [7], [8], [9], [11], but no study has yet investigated the relevance of MRI abnormalities to EDS.

The aim of the present study was to assess whether or not there is any correlation between MRI abnormalities and EDS in a consecutive series of MD patients. The influences of nocturnal breathing abnormalities and sleep morphology on EDS were also evaluated.

Section snippets

Patients

Out of 70 MD patients enrolled consecutively, 23 subjects complained of EDS, as assessed by means of a standard sleep questionnaire. Diagnosis of MD was established on the basis of the clinical and electrophysiological evidence of myotonia. Ten of the 23 patients with EDS (five male, five female; mean±SD age, 35±10 years; range, 21–49 years) gave their informed consent to participate in the study, and underwent polysomnography, the multiple sleep latency test (MSLT) and MRI. In all ten

Results

Total sleep time and time spent awake after sleep onset were longer in patients than in controls (445.6±45.8 vs. 382±67 min; P<0.02; 63.5±28.5 vs. 25±18 min; P<0.002). This difference is further emphasised by the number of awakenings (6.6±2.9 in patients, 2.7±2.2 in controls; P<0.003). However, the percentage of each sleep stage, the REM latency, the number of REM phases and the REM:NREM ratio were similar in the two subject groups.

The mean MSLT value was significantly lower in patients than in

Discussion

Our results suggest that a primary dysfunction of the CNS might play an important role in the development of EDS in MD patients. Conflicting results have been reported with regard to the effects of nocturnal sleep deprivation and disruption caused by repeated apnoeas on EDS. Guilleminault et al. [18] found a close correlation in their patients between daytime sleepiness and a high apnoea index. Other studies in which daytime somnolence could not be attributed to disrupted nocturnal sleep have,

Acknowledgements

The financial support of Telethon-Italy (grant no. E.54) is gratefully acknowledged.

References (22)

  • A. Ogata et al.

    Anterior temporal white matter lesions in myotonic dystrophy with intellectual impairment: an MRI and neuropathological study

    Neuroradiology

    (1998)
  • Cited by (45)

    • Clinical and neuroradiological correlates of sleep in myotonic dystrophy type 1

      2022, Neuromuscular Disorders
      Citation Excerpt :

      Level I attended polysomnography (PSG) and multiple sleep latency tests (MSLT) have been widely employed to characterise sleep abnormalities in DM1. Compared with controls, people with DM1 have increased total sleep time, but with greater fragmentation of sleep [7,8]. Sleep architecture is altered, including an increased proportion of total sleep time spent in slow wave and rapid eye movement (REM) stages of sleep [9,10].

    • Screening for early symptoms of respiratory involvement in myotonic dystrophy type 1 using the Respicheck questionnaire

      2020, Neuromuscular Disorders
      Citation Excerpt :

      However, symptoms of respiratory involvement are often overlooked by these patients [5,7]. More frequently symptoms such as fatigue, excessive daytime sleepiness (EDS), sleep disorders [8–13] and reduced cognitive performance, although indirectly pointing toward pulmonary function abnormalities, may be the presenting or predominant symptom of respiratory impairment in this disorder. In June 2014, during the 207th European NeuroMuscular Center (ENMC) international workshop on the diagnosis and management of chronic respiratory insufficiency in DM1 [6], a consensus statement was reached amongst the participants on the need for a respiratory symptom check-list that could briefly and quickly capture symptoms of respiratory involvement.

    • Disruption of sleep-wake continuum in myotonic dystrophy type 1: Beyond conventional sleep staging

      2018, Neuromuscular Disorders
      Citation Excerpt :

      While the successful control of SDB in this clinical population may not actually result in improved daytime sleepiness [45,46], only scarce data suggest a correlation between PLMS and ESD, that however has not been definitely acknowledged yet [47–49]. Convergent evidences argue instead for a central dysfunction involving sleep-wake and, particularly, REM sleep regulating mechanisms [38,50–53]. Data from our study support this view, since only one of the four subjects showing a mean sleep latency shorter than eight minutes (suggestive of excessive sleepiness) had both pathological AHI and PLMI, whereas one other patient had only a pathological PLMI.

    • Central Hypersomnia

      2015, Seminars in Pediatric Neurology
    View all citing articles on Scopus
    View full text