Sleep-related movement disorders in a population of patients with epilepsy: prevalence and impact of restless legs syndrome and sleep bruxism
2020; American Academy of Sleep Medicine; Volume: 16; Issue: 3 Linguagem: Inglês
10.5664/jcsm.8218
ISSN1550-9397
AutoresSamson Khachatryan, L. Ghahramanyan, Zaruhi Tavadyan, Nune S. Yeghiazaryan, Hrayr Attarian,
Tópico(s)Parkinson's Disease Mechanisms and Treatments
ResumoFree AccessScientific InvestigationsSleep-related movement disorders in a population of patients with epilepsy: prevalence and impact of restless legs syndrome and sleep bruxism Samson G. Khachatryan, MD, PhD, Lilit Ghahramanyan, MSc, Zaruhi Tavadyan, MD, Nune Yeghiazaryan, MD, Hrayr P. Attarian, MD Samson G. Khachatryan, MD, PhD *Address correspondence to: Samson G. Khachatryan (Khachatryan S.G.), Neurologist, Somnologist (ESRS cert.), Chair, Department of Neurology, National Institute of Health, Armenia, Sleep and Movement Disorders Center, Somnus Neurology Clinic, Titogradyan 14 Yerevan 0087 Armenia; Tel: +374 91 519641; Email: E-mail Address: [email protected] Sleep and Movement Disorders Center, Somnus Neurology Clinic, Yerevan, Armenia; Department of Neurology and Neurosurgery, National Institute of Health, Ministry of Health, Yerevan, Armenia; , Lilit Ghahramanyan, MSc Sleep and Movement Disorders Center, Somnus Neurology Clinic, Yerevan, Armenia; , Zaruhi Tavadyan, MD Sleep and Movement Disorders Center, Somnus Neurology Clinic, Yerevan, Armenia; Department of Neurology and Neurosurgery, National Institute of Health, Ministry of Health, Yerevan, Armenia; , Nune Yeghiazaryan, MD Department of Neurology and Neurosurgery, National Institute of Health, Ministry of Health, Yerevan, Armenia; Republic Epilepsy Center, Erebouni Medical Center, Yerevan, Armenia; , Hrayr P. Attarian, MD Center for Sleep Disorders, Northwestern University Feinberg School of Medicine, Chicago, Illinois Published Online:March 15, 2020https://doi.org/10.5664/jcsm.8218Cited by:17SectionsAbstractPDF ShareShare onFacebookTwitterLinkedInRedditEmail ToolsAdd to favoritesDownload CitationsTrack Citations AboutABSTRACTStudy Objectives:Sleep disorders are frequent co-occurrences in patients with epilepsy (PWE), but sleep-disordered breathing and insomnia are better studied than others. Our aim was to study sleep-related movement disorders in epilepsy.Methods:We interviewed 175 PWE (age range 18–71 years, mean 35.4 years, 47.4% female) and 130 controls (age range 18–72 years, mean 33.6 years, 47.7% females). Restless legs syndrome (RLS) and sleep bruxism (SB) were diagnosed by International RLS Study Group's diagnostic criteria and International Classification of Sleep Disorders, Third Edition criteria respectively. We also used Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and Berlin Questionnaire (BQ).Results:Our findings suggest that RLS and SB are encountered more frequently in PWE than controls: 20.6% versus 6.1% for RLS, and 23.7% versus 5.4% for SB (P < .05). Insomnia was more prevalent in epilepsy (46.2% versus 24.6%, P < .05) while poor sleep hygiene occurred more frequently in controls (28.3% versus 53.8%), (P < .05). PWE had poorer sleep by PSQI 61.7% versus 41.5% (P < .05). Sleepiness (38.7% versus 39.2%) and snoring (42.8% versus 40.8%) were equally distributed in both groups, also ESS and BQ not showing significant differences (P > .05).Conclusions:Our study demonstrates that sleep disorders comprise important part of epilepsy comorbidity. We demonstrated that unselected PWE had higher prevalence of RLS. For the first time we show higher prevalence of sleep bruxism in epilepsy population. Also complaints of insomnia are seen more in PWE, while snoring and poor sleep hygiene not.Citation:Khachatryan SG, Ghahramanyan L, Tavadyan Z, Yeghiazaryan N, Attarian HP. Sleep-related movement disorders in a population of patients with epilepsy: prevalence and impact of restless legs syndrome and sleep bruxism. J Clin Sleep Med. 2020;16(3):409–414.BRIEF SUMMARYCurrent Knowledge/Study Rationale: Sleep disorders are prevalent in epilepsy, while insomnia and sleep apnea are considered serious comorbidities in this population. Other entities like sleep-related movement disorders (eg, restless legs syndrome, sleep bruxism) also can impact the course of epilepsy through sleep-disturbing effects.Study Impact: This study sheds new light on importance of sleep-related movement disorders screening in epilepsy, as we found significantly higher rates of restless legs syndrome and sleep bruxism in epilepsy, the latter finding being reported for the first time. Our data support higher presence of insomnia, but not snoring in epilepsy than controls, and somewhat surprisingly patients with epilepsy reported better sleep hygiene than healthy individuals.INTRODUCTIONEpilepsy comorbidities are challenges for every health care provider who manages and treats patients with epilepsy (PWE). Lack of adequate sleep and presence of sleep disorders are well-known causes of complication to the course and management of this complex disease. Both epilepsy and sleep disorders are prevalent in general population.1,2 The two most prevalent sleep disorders and the ones best recognized because of their impact on public health are insomnia and sleep-disordered breathing (SDB).2 Still there are others, including sleep-related movement disorders (restless legs syndrome and sleep bruxism), circadian rhythm sleep disorders, hypersomnias of central origin (eg narcolepsy), and parasomnias, which can also impact epilepsy care. During recent decades more attention is paid to coexistence and role of primary sleep disorders in epilepsy, their impact on disease course and effects on quality of life.3–6Sleep disorders may influence epilepsy management and even cause diagnostic problems when occur alongside with epilepsy.7 Some important scientific data are accumulating recent years on this topic. Mostly these studies are in concordance with the fact that sleep disorders symptoms are more prevalent among PWE than general population and some other groups.8In particular, insomnia and obstructive sleep apnea (OSA) are shown to negatively impact seizure frequency and quality of life in PWE.9-13Still, only a few studies addressed other sleep disorders and, in particular, movement disorders related to sleep. Their results on prevalence of restless legs syndrome (RLS) in epilepsy are controversial.14,15 Only one study reported sleep bruxism (SB) prevalence in PWE, and it was not different from controls.7An adequate sleep related symptom inquiry is necessary for a focused assessment of primary sleep disorders. Considering the above-mentioned we aimed to study the prevalence of sleep disorders among PWE through detailed clinical interview and compare these findings with healthy controls.METHODSThe material was obtained from two tertiary centers for epilepsy and sleep disorders, which are based in a single multidisciplinary hospital. A cross-sectional design was used for data collection. Participants in the current study are divided into epilepsy group (EG) and control group (CG).Adult PWE, aged 18 years and above, who admitted to tertiary epilepsy center for assessment of their de novo or already diagnosed seizure disorders were included in this study. Their diagnosis of epilepsy was based on the current recommendations of two or more spontaneous epileptic seizures, supported, when possible, by electroencephalographic (EEG) and neuroimaging studies. In a few cases occurrence of one seizure with high probability of second seizure according to EEG and neuroimaging results were considered eligible in accordance with the same recommendations.16 Exclusion criteria for EG: inability of participant to communicate due to language barrier, speech or cognitive problem, severe medical or neuropsychiatric comorbidity, symptomatic seizures due to acute brain disease, and lack of adherence with the evaluation procedure.Participants in CG were recruited on random basis and had no relationship with participants from EG. The following inclusion criteria were fulfilled for CG: adults aged 18 and above, fluent in Armenian language, with normal communication ability and no epilepsy diagnosis or loss of consciousness episodes in medical history, no known severe medical or neuropsychiatric disorder.Assessments of PWE were carried out by investigators experienced in management of patients with sleep disorders and epilepsy (S.K., L.G.) at the tertiary sleep disorders clinic. We used a detailed clinical interview approach, systematically asking patients about the most important aspects of sleep disorders. Inclusion and assessment were not dependent on whether PWE report any sleep symptom spontaneously or not. Also, when possible, attention was given to the reports and descriptions from relatives, bed partners, and spouses of participants in both groups.A list of sleep-related symptoms, used also for routine assessment of patients with sleep complaints at a specialized sleep clinic, was used for evaluations in this study. Investigators administered the questions regarding all listed symptoms to participants during interview in a standardized fashion and on yes/no answer basis. Additional clarifying questions were allowed to better understand the nature of their response, differentiate from other conditions and added as a description in the form. This was particularly important for helping to clarify the nature of rare or unusual sleep disorder symptoms like sleep paralysis to respondents, so they could better shape their answers. When respondents reported symptoms characteristic of a particular sleep disorder and no additional investigations were needed for diagnosis except clinical interviewing (insomnia, RLS, bruxism), investigators used International Classification of Sleep Disorders, Third Edition (ICSD-3) diagnostic criteria for a clinical diagnosis.17The list of investigated sleep symptoms with additional descriptions and comments on specific sleep disorders we diagnosed on clinical grounds follows. Insomnia was defined as inability to fall asleep in the beginning of sleep or after awakening from sleep despite normal conditions, will to sleep and time for sleep for at least one preceding month. We considered participants' sleep unrefreshing if it was not perceived as reinvigorating for most of the nights per month. Information about the participants' sleep-wake habits was collected. Excessive daytime sleepiness (EDS) and unpredicted sleep attacks noted separately.We used the four diagnostic questions set forth by the International RLS Study Group (IRLSSG).18 The participants were interviewed by a clinician or research assistant who has experience in RLS, asking the following essential questions: (1) do you have an urge to move the legs, accompanied by uncomfortable sensations or restlessness in limbs (typically legs);( 2) does your urge to move begin or increase in intensity during periods of rest (different situations were suggested if not clear), (3) does any type of movement or motor activity help to relieve the urge or unpleasant sensations in part or totally, (4) does your urge to move begin or worsen in the evening or at night. According to ICSD-3 criteria,17 if this condition is not better explained by another medical or behavioral condition and causes distress, sleep disturbance, or impairs other important functions, a clinical diagnosis of RLS could be made, provided the previous four questions are answered positively.Tooth-grinding while asleep was also included in our form, as sleep bruxism is a movement disorder of sleep, associated with poor sleep quality and wearing of teeth. Reports of frequent or regular tooth-grinding sounds or jaw clenching in sleep by patients, bed partners and relatives were considered positive for SB.Vivid, negative, or excessive dreams, such as nightmares, sleep-related hallucinations and other REM-related phenomena were also addressed.For additional assessments of major sleep disorders we used the validated Armenian versions of Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and Berlin Questionnaire (BQ) to assess sleep quality, daytime sleepiness and sleep-disordered breathing respectively. PSQI is a patient-administered scale with a special calculation system which gives a final numeric result. A cutoff value of > 5 by PSQI represents poor sleep quality.19 ESS consists of 8 questions each evaluated from 0 to 3. They are used to assess participant's probability of sleeping during daytime in different situations. The possible maximum number of points is 24 and the cutoff point for pathological somnolence is considered > 10.20 BQ is a questionnaire focused on snoring and sleep apnea detection with a qualitative division of participants into high and low probability of sleep-disordered breathing.21The study was approved by the ethical committee of Yerevan State Medical University. Statistical analysis was performed by NCSS v.10 software (NCSS LLC, Kaysville, UT, USA) and included descriptive presentation of data, Mann-Whitney U and Pearson chi-squared tests.RESULTSOverall, 175 PWE were included in the EG, age range 18–71 years, mean age 35.4 ± 13.7 years, and 83 of whom were female (47.4%). We included 130 participants in CG, age range 18–72 years, mean age 33.6 ± 11.3 years (P > .05), and 47.7% were female. EG was further divided into subgroups according to main epilepsy category (focal or generalized) and current antiepileptic drug (AED) therapy. Our PWE mostly had focal epilepsy (136 cases [77.7%]) with further 39 cases (22.3%) of generalized epilepsy. Demographic data of both groups are summarized in Table 1.Table 1 Demographic data for epilepsy and control groups.EG (n = 175)CG (n = 130)χ2PAge, years, mean ± SD (range)35.4 ± 13.7 (18–71)33.6 ± 11.3 (18–72)n/a> .05Sex, female, n (%)83 (47.4)62 (47.7)0.002> .05Married, n (%)91 (52.0)49 (46.7)0.75> .05Employed, n (%)47 (26.9)82 (63.1)40.1< .05CG = control group, EG = epilepsy group, n/a = not applicable.Among PWE, 74.3% were on AED therapy. Patients without AED therapy were either recently diagnosed and awaiting their prescription, or were poorly adherent and had withdrawn from therapy for the previous 3 or more months, based on their own or family decisions. The results of sleep symptom distribution between groups are summarized in Table 2.Table 2 Comparison of sleep disorders and related symptoms and questionnaire results between epilepsy and control groups.Clinical Symptoms and ScalesEGCGχ2PInsomnia80 (46.2)32 (24.6)14.9< .05Unrefreshing sleep56 (32.4)54 (41.5)2.7> .05Poor sleep hygiene49 (28.3)70 (53.8)20.3< .05Excessive daytime sleepiness67 (38.7)51 (39.2)0.008> .05Unpredicted sleep attacks19 (11.0)19 (14.6)0.9> .05Sleep paralysis7 (4.05)2 (1.54)1.61> .05Snoring74 (42.8)53 (40.8)0.12> .05Breathing stops in sleep41 (23.7)12 (9.2)10.8< .05Restless legs syndrome (all four diagnostic criteria positive)36 (20.6)8 (6.15)12.6< .05Repetitive movements in limbs while asleep52 (30.1)15 (11.5)14.8< .05Abnormal behaviors in sleep44 (25.4)22 (16.9)3.15> .05Abnormal dreams38 (22.0)27 (20.8)0.06> .05Nocturia/enuresis23 (13.3)1 (0.8)16.0< .05Sleep bruxism41 (23.7)7 (5.4)18.7< .05Pittsburgh Sleep Quality Index105 (62.5)51 (39.2)15.9< .05Epworth Sleepiness Scale (cutoff > 10)20 (11.8)19 (14.6)0.5> .05Berlin Questionnaire45 (26.95)25 (19.2)2.4> .05Data presented as n (%). CG = control group, EG = epilepsy group.PWE had higher presence of insomnia than controls (46.2% versus 24.6%, P < .05), while unrefreshing sleep was not significantly different between groups (EG versus CG, 32.4% versus 41.5%, P > .05). Interestingly, inappropriate sleep-wake time was reported more in controls (53.8%) than in epilepsy (28.3%, P < .05). Our data on excessive daytime sleepiness and unpredicted sleep attacks brought similarly high results for both groups (P > .05). We found 7 cases of sleep paralysis (4.05%) in EG, versus 2 cases in controls (1.54%, P > .05). Snoring was found equally present in both epilepsy (42.8%) and control (40.8%) groups (P > .05). However, awakenings due to breathing stops were significantly more prevalent in epilepsy population (23.7% versus 9.2%; P < .05).In regard to sleep-related movement disorders, we obtained important results. PWE had a significantly higher prevalence of RLS (20.6%) than controls (6.1%, P < .05). Moreover, there were more reports of sleep-related tooth-grinding in PWE (23.7% versus 5.4%, P < .05).PSQI questionnaire results revealed poorer sleep quality in EG both with quantitative and qualitative approaches. PSQI mean score was 7.9 for EG compared to 5.15 in controls (P < .05). Meanwhile percentage of participants rated as poor sleepers according to PSQI was also higher in EG: 62.5% versus 39.2% (P < .05). Using ESS with a cutoff point of > 10 we found no significant difference between EG and CG. EDS was present in 11.8% of EG and 14.6% of controls (P > .05). Although ESS absolute means showed slightly higher EDS level in CG: 4.9 versus 5.9 (P < .05). BQ analysis also showed no significant difference for SDB risk between EG and CG (26.95% versus 19.2%, respectively; P > .05).We further conducted comparisons within epilepsy group results according to the main categories of epilepsy and found no statistically significant differences (P > .05) between patients with focal and generalized epilepsy (Table 3).Table 3 Comparison of sleep disorders and related symptoms between focal and generalized epilepsies, and patients on AED therapy or not.Clinical SymptomsFocalGeneralizedχ2PNo AEDOn AEDχ2PInsomnia64 (47.8)16 (41.0)0.55> .0515 (34.1)65 (50.4)3.50> .05Unrefreshing sleep39 (29.1)17 (43.6)2.89> .0513 (29.55)43 (33.3)0.21> .05Poor sleep hygiene35 (26.1)14 (35.9)1.42> .0514 (31.8)35 (27.1)0.35> .05Excessive daytime sleepiness57 (42.5)10 (25.6)3.63> .0513 (29.55)54 (41.9)2.09> .05Unpredicted sleep attacks14 (10.45)5 (12.8)0.17> .050 (0.0)19 (14.7)7.28< .05Sleep paralysis7 (5.2)0 (0.0)2.12> .051 (2.3)6 (4.7)0.47> .05Snoring62 (46.3)12 (30.8)2.96> .0518 (40.9)56 (43.4)0.08> .05Breathing stops in sleep34 (25.4)7 (17.95)0.92> .0510 (22.7)31 (24.0)0.03> .05Restless legs syndrome (all four diagnostic criteria positive)29 (21.3)7 (17.95)0.21> .059 (20.0)27 (20.1)0.01> .05Repetitive movements in limbs while asleep44 (32.8)8 (20.5)2.18> .0512 (27.3)40 (31.0)0.21> .05Abnormal behaviors in sleep29 (21.6)14 (35.95)3.28> .054 (9.1)39 (30.2)7.85< .05Abnormal dreams31 (23.1)7 (17.95)0.47> .058 (18.2)30 (23.3)0.49> .05Nocturia/enuresis18 (13.4)5 (12.8)0.01> .055 (11.4)18 (14.0)0.19> .05Sleep bruxism30 (22.4)11 (28.2)0.56> .057 (15.9)34 (26.4)1.98> .05Data presented as n (%). AED = antiepileptic drug.We obtained also another set of variables from evaluating the link between AED therapy and sleep disorders (Table 3). Our results show a higher prevalence of sleep attacks in PWE receiving pharmacotherapy (14.7% versus 0.0%, P < .05). In treated epilepsy subgroup there were also trends toward a higher prevalence of insomnia (50.4% versus 34.1%, P > .05), EDS (41.9% versus 29.6%, P > .05).DISCUSSIONIn this study we compared sleep-related symptoms in adult PWE and healthy age-, sex-, and marital status-matched control participants. Our findings show that PWE have more RLS and sleep-related bruxism than healthy controls.The method of sleep interview based on ICSD-3 criteria is different from some other similar studies that often use patient-administered questionnaire approach. With our design we were able to reveal important sleep symptoms usually ignored or underreported by the patients while also supported by questionnaires.Our controls reported poorer sleep hygiene than PWE. Interestingly, these results agree with the findings reported by other authors, who also saw more inappropriate schedules and poor sleep hygiene in controls.22 Even if high prevalence of daytime sleepiness among PWE previously was attributed mostly to AEDs effects,23 we could not replicate this finding in our sample, the same issue also raised by others.3 Although high in numbers, this symptom was equally distributed in both groups what was also supported by ESS results. The fact that poor sleep habits were seen more in controls could possibly be a cause of increased EDS in this group, thus equalizing with EDS data from epilepsy population.In our study we found that sleep paralysis is seen more in PWE. Although this is not supported by significant difference, we see a clear trend, which deserves further investigation. This may be interpreted as possible AED side effect or misinterpretation of sleep-related simple or complex partial epileptic seizures, because all PWE with sleep paralysis had focal epilepsy and most were on AED therapy.We found an interesting discrepancy regarding SDB, as snoring complaint had similar distribution in both groups. Anyway, "awakening with shortness of breath/witnessed breathing stops" are more frequently seen in epilepsy. It is in line with other similar findings and proves that SDB, and especially OSA, could be more prevalent in PWE than in the general population.24 However, using BQ we did not register any difference. According to our results waking with choking, shortness of breath reported by patient or presence of breathing stops witnessed by a bed partner/relative could be more valuable and specific symptom than snoring in terms of assessing the risk of SDB.An important part of our study was to evaluate prevalence of sleep-related movement disorders in epilepsy population. In this study we focused our attention on RLS and SB as these entities frequently fall out of attention in other studies. We demonstrated that RLS had higher prevalence in epilepsy compared to healthy population. In previous studies investigators did not find difference compared to controls, although they used a single question-based approach.3,7 Our study shows that using required 4-question-based approach in diagnosing clinical RLS changes the situation. Two recent studies shed some further light on this relationship. One of them did not find higher prevalence of RLS in unselected adult epilepsy population (5.8%) compared to controls, although they used a previous general population study material as a control group.14 In another study, Geyer et al found higher prevalence of RLS in a selected population of exclusively temporal lobe epilepsy patients during presurgical evaluation.15 Interestingly, they report higher prevalence of RLS in patients with right temporal lobe epilepsy, while RLS in their left temporal lobe epilepsy group was not significantly different from controls. However, epilepsy patients in this study were compared to a control group of individuals evaluated for carpal tunnel syndrome at a neurology clinic.15 In comparison to these reports our finding of higher RLS prevalence is based on unselected epilepsy population which was compared to controls randomly selected from general population. This is a strength of our study that essentially adds to the previous knowledge of this poorly studied relationship.It is not clear, why RLS was seen more in PWE, but one explanation could be the disturbed iron metabolism. It is well known, that RLS is connected to altered brain iron status.25 There are some reports, showing that iron metabolism could be abnormal in focal epilepsy, with iron levels decreased in the subcortical structures such as substantia nigra, red nucleus, and basal ganglia in mesial temporal lobe epilepsy.26,27 Thus, we may think about one possible common mechanism for epilepsy and RLS.Knowing that RLS is more prevalent in adult PWE brings difficulties to epilepsy management. First, RLS is connected to delay of sleep onset due to bedtime restlessness and decrease of total sleep time. Additionally, one may think of poor sleep quality due to periodic leg movements in sleep, a frequent feature of RLS associated with arousals. RLS, provided it is clinically significant, may require additional pharmacotherapy or changes in the current antiepileptic medications, thus bearing drug-drug interaction or seizure exacerbation potential. Nevertheless, identifying and treating RLS could bring benefit to overall management of PWE with expected better outcomes in seizure control and quality of life. Overall, the basis for this interesting relationship between RLS and epilepsy is not well understood and needs further studies probably more focused on neurophysiology.Another very important finding of our study is the high prevalence of SB in epilepsy. To the best of our knowledge, this is the first report of higher prevalence of SB in adults with epilepsy compared to general population. It is important to mention, that at the time of interview none of enrolled participants were taking antidepressant medication and a very few took barbiturates as possible causes of secondary SB.28 Most of them were taking carbamazepine and valproate or were drug naïve. This relationship is further strengthened by the fact that although some AEDs may have beneficial therapeutic effects on SB, still SB was higher in our PWE.29,30 As an arousal-associated motor phenomenon SB could be a possible provoker of seizures in PWE by analogy with sleep apnea. On the other hand, higher SB prevalence in PWE could be a result of arousal system variations characteristic of epilepsy.31 It is shown that cyclic alternating pattern as a marker of sleep instability could be influenced negatively by epileptic discharges and seizures during sleep. This could lead to increased occurrence of arousal related nonepileptic motor phenomena like sleep bruxism seen in our PWE.We are aware of some limitations of this study, especially that our data is clinical and questionnaire-based and is not presenting objective sleep measurement. We also did not include comparisons with seizure characteristics.In conclusion, with this study we obtained interesting and new results that could be used for further investigation of the relationship between different sleep disorders and epilepsy. We report higher prevalence of RLS, similar to a few published studies, but unlike others, we studied unselected PWE with different syndromes and control participants from general population. For the first time we report a higher prevalence of SB in epilepsy compared to a healthy control population. We think that RLS and SB together with previously reported other accompanying sleep disorders could serve as important additions to the list of medically refractory epilepsy causing factors.We will use these findings to educate the medical community as well as the public on the importance of sleep complaints and sleep disorders in the care of PWE, primarily because these are frequently ignored or underreported. We hope to develop awareness among and tools for busy clinicians to quickly screen for sleep complaints in PWE. We also hope to expand on the current study and use more objective measures to explore the interactions between sleep disorders and epilepsy, as this is an important element in improving management of PWE particularly medically intractable epilepsy.DISCLOSURE STATEMENTAll authors have seen and approved the manuscript. Work for this study was performed at Somnus Neurology Clinic's Sleep and Movement Disorders Center and Republic Epilepsy Center, Erebouni Medical Center, Yerevan, Armenia. The authors report no conflicts of interest.ABBREVIATIONSAEDantiepileptic drugsBQBerlin questionnaireCGcontrol groupEDSexcessive daytime sleepinessEEGelectroencephalographyEGepilepsy groupESSEpworth Sleepiness ScaleICSDInternational Classification of Sleep DisordersIRLSSGInternational RLS Study GroupOSAobstructive sleep apneaPSQIPittsburgh Sleep Quality IndexPWEpatients with epilepsyRLSrestless legs syndromeSBsleep bruxismSDBsleep-disordered breathingACKNOWLEDGMENTSThe authors thank the medical staff at Republic epilepsy center and Somnus sleep center for their kind help with patient referral, assessment and management. The authors thank Dr. Garik Yeganyan and Mariam Isayan for additional help during preparation of the material.REFERENCES1. Singh A, Trevick S. The epidemiology of global epilepsy. Neurol Clin. 2016;34(4):837–847. https://doi.org/10.1016/j.ncl.2016.06.015 CrossrefGoogle Scholar2. Partinen M. Epidemiology of sleep disorders. Handb Clin Neurol. 2011;98:275–314. https://doi.org/10.1016/B978-0-444-52006-7.00018-6 CrossrefGoogle Scholar3. Malow B, Bowes R, Lin X. Predictors of sleepiness in epilepsy patients. Sleep. 1997;20(12):1105–1110. https://doi.org/10.1093/sleep/20.12.1105 CrossrefGoogle Scholar4. de Weerd A, De Haas S, Otte A, et al.. Subjective sleep disturbance in patients with partial epilepsy: a questionnaire-based study on prevalence and impact on quality of life. Epilepsia. 2004;45(11):1397–1404. https://doi.org/10.1111/j.0013-9580.2004.46703.x CrossrefGoogle Scholar5. Piperidou C, Karlovasitou A, Triantafyllou N, et al.. Influence of sleep disturbance on quality of life of patients with epilepsy. Seizure. 2008;17(7):588–594. https://doi.org/10.1016/j.seizure.2008.02.005 CrossrefGoogle Scholar6. Roshan S, Puri V, Chaudhry N, Gupta A, Rabi SK. Sleep abnormalities in juvenile myoclonic epilepsy—a sleep questionnaire and polysomnography based study. Seizure. 2017;50:194–201. https://doi.org/10.1016/j.seizure.2017.06.021 CrossrefGoogle Scholar7. Khatami R, Zutter D, Siegel A, Mathis J, Donati F, Bassetti C. Sleep-wake habits and disorders in a series of 100 adult epilepsy patients—A prospective study. Seizure. 2006;15(5):299–306. https://doi.org/10.1016/j.seizure.2006.02.018 CrossrefGoogle Scholar8. van Golde EG, Gutter T, de Weerd AW. Sleep disturbances in people with epilepsy; prevalence, impact and treatment. Sleep Med Rev. 2011;15(6):357–368. https://doi.org/10.1016/j.smrv.2011.01.002 CrossrefGoogle Scholar9. Lopez MR, Cheng JY, Kanner AM, Carvalho DZ, Diamond JA, Wallace DM. Insomnia symptoms in South Florida military veterans with epilepsy. Epilepsy Behav. 2013;27(1):159–164. https://doi.org/10.1016/j.yebeh.2013.01.008 CrossrefGoogle Scholar10. Vendrame M, Yang B, Jackson S, Auerbach SH. Insomnia and epilepsy: a questionnaire-based study. J Clin Sleep Med. 2013;9(2):141–146. https://doi.org/10.5664/jcsm.2410 LinkGoogle Scholar11. Quigg M,
Referência(s)