Periodic Limb Movements During Sleep are More Severe in Narcolepsy with Cataplexy than in Narcolepsy without Cataplexy
Abstract
Introduction: Periodic limb movements in sleep (PLMS) are repetitive stereotyped movements of extremities, particularly of the legs. Some studies identified narcolepsy to be associated with higher PLMS occurrence.
Methods: A retrospective study including 78 patients with narcolepsy with cataplexy (NC) and 29 patients with narcolepsy without cataplexy (NwoC) aged 19 to 86 years, 50 women and 57 men. All subjects underwent a clinical examination including video-polysomnography 8 hours at night time and the multiple sleep latency test (MSLT).
Results: PLMS characterized by the periodic leg movements index (PLMI - number of periodic leg movements per 1 hour) >= 15 were found in 40% of the total of 107 patients - 43% of NC and 32% of NwoC. PLMS was associated with higher age and with lower sleep efficacy.
The mean PLMI of NC and NwoC was different 24.3 +- 30.2 and 12.6 +- 20.8, resp. Similar values were identified when subjects not using antidepressants during the study were evaluated in these same subgroups.
PLMI values (31.2 +- 33.3) were higher in patients using antidepressants than in patients never taking antidepressants (15.4 +- 23.7), irrespective of whether antidepressants were used before the study only or before and during the study. However, patients with the history of antidepressants use were older.
Conclusion: PLMS are frequent comorbidity in NC and it is more frequent in NC than in NwoC.