Introduction: Myotonic dystrophy type I (DM1) is the most common adult onset muscular dystrophy. Sleep disruption and excessive daytime sleepiness (EDS) are well acknowledged symptoms in myotonic dystrophy type I (DM1). Fragmented nocturnal sleep, sleep-disordered breathing (SDB), and periodic limb movements (PLMS) have been implicated, but a central dysfunction of sleep-wake regulation is likely to play a pivotal role. Few studies evaluated sleep macrostructure in DM1, reporting peculiar alterations, but none investigated more refined sleep variables as sleep microstructure. Materials and methods: We included 8 DM1 (6M; 34.0±10.5 years) and 10 healthy controls (7 M; 34.6±15.3 years) that underwent in-lab polysomnographic nocturnal sleep and multiple sleep latency test (MSLT). Sleep stages and polygraphic events were scored according with standard criteria revised in 2007 by American Academy of Sleep Medicine (2007); sleep microstructure was analysed by means of Cyclic Alternating Pattern (CAP). Results: Although not statistically significant, DM1 patients had decreased TST. DM1 showed a significant increase in REM sleep percentage and decreased N2; N3, although not significantly, was increased. Three patients, but no control, showed SOREM in nocturnal PSG. CAP analysis pointed out increased sleep instability (CAP rate). DM1 patients had significantly shorter mean sleep latency; four of the eight patients had a pathological mean sleep latency. Five patients showed at least one SOREM and, when including also nocturnal PSG, all these patients had at least two SOREM. There were no significant differences among two groups regarding apnea-hypopnea and periodic leg movements index. Conclusions: The peculiar macrostructural pattern confirms a narcoleptic-like phenotype in DM1 and points, from a pathophysiological point of view to a REM sleep dysregulation (sleep onset REM periods, fragmented REM sleep) that may account for EDS. Higher CAP rate suggests increased sleep instability in DM1 patients. Our data further support a CNS involvement in DM1 pathophysiology and suggest a role for the mechanisms underlying central sleep regulation in disrupting sleep-wake continuum, including sleep instability and EDS, in DM1.
DISRUPTION OF SLEEP-WAKE CONTINUUM IN MYOTONIC DYSTROPHY TYPE I: SLEEP MACROSTRUCTURAL AND MICROSTRUCTURAL FINDINGS
Maestri, M;Bonuccelli, U;Bonanni, E
2017-01-01
Abstract
Introduction: Myotonic dystrophy type I (DM1) is the most common adult onset muscular dystrophy. Sleep disruption and excessive daytime sleepiness (EDS) are well acknowledged symptoms in myotonic dystrophy type I (DM1). Fragmented nocturnal sleep, sleep-disordered breathing (SDB), and periodic limb movements (PLMS) have been implicated, but a central dysfunction of sleep-wake regulation is likely to play a pivotal role. Few studies evaluated sleep macrostructure in DM1, reporting peculiar alterations, but none investigated more refined sleep variables as sleep microstructure. Materials and methods: We included 8 DM1 (6M; 34.0±10.5 years) and 10 healthy controls (7 M; 34.6±15.3 years) that underwent in-lab polysomnographic nocturnal sleep and multiple sleep latency test (MSLT). Sleep stages and polygraphic events were scored according with standard criteria revised in 2007 by American Academy of Sleep Medicine (2007); sleep microstructure was analysed by means of Cyclic Alternating Pattern (CAP). Results: Although not statistically significant, DM1 patients had decreased TST. DM1 showed a significant increase in REM sleep percentage and decreased N2; N3, although not significantly, was increased. Three patients, but no control, showed SOREM in nocturnal PSG. CAP analysis pointed out increased sleep instability (CAP rate). DM1 patients had significantly shorter mean sleep latency; four of the eight patients had a pathological mean sleep latency. Five patients showed at least one SOREM and, when including also nocturnal PSG, all these patients had at least two SOREM. There were no significant differences among two groups regarding apnea-hypopnea and periodic leg movements index. Conclusions: The peculiar macrostructural pattern confirms a narcoleptic-like phenotype in DM1 and points, from a pathophysiological point of view to a REM sleep dysregulation (sleep onset REM periods, fragmented REM sleep) that may account for EDS. Higher CAP rate suggests increased sleep instability in DM1 patients. Our data further support a CNS involvement in DM1 pathophysiology and suggest a role for the mechanisms underlying central sleep regulation in disrupting sleep-wake continuum, including sleep instability and EDS, in DM1.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
