REM Latency Research Articles

Independent Component Analysis and Graph Theoretical Analysis in Patients with Narcolepsy

The present study was aimed to evaluate resting-state functional connectivity and topological properties of brain networks in narcolepsy patients compared with healthy controls. Resting-state fMRI was performed in 26 adult narcolepsy patients and 30 matched healthy controls. MRI data were first analyzed by group independent component analysis, then a graph theoretical method was applied to evaluate the topological properties in the whole brain. Small-world network parameters and nodal topological properties were measured. Altered topological properties in brain areas between groups were selected as region-of-interest seeds, then the functional connectivity among these seeds was compared between groups. Partial correlation analysis was performed to evaluate the relationship between the severity of sleepiness and functional connectivity or topological properties in the narcolepsy patients. Twenty-one independent components out of 48 were obtained. Compared with healthy controls, the narcolepsy patients exhibited significantly decreased functional connectivity within the executive and salience networks, along with increased functional connectivity in the bilateral frontal lobes within the executive network. There were no differences in small-world network properties between patients and controls. The altered brain areas in nodal topological properties between groups were mainly in the inferior frontal cortex, basal ganglia, anterior cingulate, sensory cortex, supplementary motor cortex, and visual cortex. In the partial correlation analysis, nodal topological properties in the putamen, anterior cingulate, and sensory cortex as well as functional connectivity between these regions were correlated with the severity of sleepiness (sleep latency, REM sleep latency, and Epworth sleepiness score) among narcolepsy patients. Altered connectivity within the executive and salience networks was found in narcolepsy patients. Functional connection changes between the left frontal cortex and left caudate nucleus may be one of the parameters describing the severity of narcolepsy. Changes in the nodal topological properties in the left putamen and left posterior cingulate, changes in functional connectivity between the left supplementary motor area and right occipital as well as in functional connectivity between the left anterior cingulate gyrus and bilateral postcentral gyrus can be considered as a specific indicator for evaluating the severity of narcolepsy.

REM sleep fragmentation associated with depressive symptoms and genetic risk for depression in a community-based sample of adolescents

IntroductionFragmented REM sleep may impede overnight resolution of distress and increase depressive symptoms. Furthermore, both fragmented REM and depressive symptoms may share a common genetic factor. We explored the associations between REM sleep fragmentation, depressive symptoms, and a polygenic risk score (PRS) for depression among adolescents. MethodsAbout 161 adolescents (mean age 16.9 ± 0.1 years) from a birth cohort underwent a sleep EEG and completed the Beck Depression Inventory-II the same day. We calculated PRSes for depressive symptoms with PRSice 1.25 software using weights from a recent genome-wide association study for dimensions of depressive symptoms (negative emotion, lack of positive emotion and somatic complaints). REM fragmentation in relation to entire REM duration was manually calculated from all REM epochs. REM latency and density were derived using SomnoMedics DOMINO software. ResultsPRSes for somatic complaints and lack of positive emotions were associated with higher REM fragmentation percent. A higher level of depressive symptoms was associated with increased percent of REM fragmentation and higher REM density, independently of the genetic risks. Belonging to the highest decile in depressive symptoms was associated with a 2.9- and 7.6-fold risk of belonging to the highest tertile in REM fragmentation and density. In addition, higher PRS for somatic complaints had an independent, additive effect on increased REM fragmentation. LimitationA single night's sleep EEG was measured, thus the night-to-night stability of the REM fragmentation-depressive symptom link is unclear. ConclusionDepressive symptoms and genetic risk score for somatic complaints are independently associated with more fragmented REM sleep. This offers new insights on the quality of sleep and its relation to adolescents’ mood.

Effects of Evening Exercise on Sleep in Healthy Participants: A Systematic Review and Meta-Analysis.

Current recommendations advise against exercising in the evening because of potential adverse effects on sleep. The aim of this systematic review was to investigate the extent to which evening exercise affects sleep and whether variables such as exercise intensity or duration modify the response. A systematic search was performed in PubMed, Cochrane, EMBASE, PsycINFO, and CINAHL databases. Studies evaluating sleep after a single session of evening physical exercise compared to a no-exercise control in healthy adults were included. All analyses are based on random effect models. The search yielded 11,717 references, of which 23 were included. Compared to control, evening exercise significantly increased rapid eye movement latency (+ 7.7min; p = 0.032) and slow-wave sleep (+ 1.3 percentage points [pp]; p = 0.041), while it decreased stage1 sleep (- 0.9pp; p = 0.001). Moderator analyses revealed that a higher temperature at bedtime was associated with lower sleep efficiency (SE) (b = - 11.6pp; p = 0.020) and more wake after sleep onset (WASO; b = + 37.6min; p = 0.0495). A higher level of physical stress (exercise intensity relative to baseline physical activity) was associated with lower SE (- 3.2pp; p = 0.036) and more WASO (+ 21.9min; p = 0.044). Compared to cycling, running was associated with less WASO (- 12.7min; p = 0.037). All significant moderating effects disappeared after removal of one study. Overall, the studies reviewed here do not support the hypothesis that evening exercise negatively affects sleep, in fact rather the opposite. However, sleep-onset latency, total sleep time, and SE might be impaired after vigorous exercise ending ≤ 1h before bedtime.

Disturbed sleep in cluster headache is not the result of transient processes associated with the cluster period.

Cluster headache (CH) is characterized by severe, unilateral attacks of pain and a high nocturnal attack burden. It remains unknown whether perturbations of sleep are solely present during the CH bout. Therefore, we aimed to investigate differences in sleep between the bout and remission period in patients with episodic CH and, secondly, to compare patients in the two phases with controls. Patients with episodic CH (aged 18-65years), diagnosed according to the International Classification of Headache Disorders 2nd edition, were admitted for polysomnography at the Danish Center for Sleep Medicine in bout and in remission. The macrostructure of sleep, including arousals, breathing parameters, limb movements and periodic limb movements, was compared with 25 age-, sex- and body mass index-matched healthy controls. There were no differences in any of the sleep parameters for patients in bout (n=32) compared with patients in remission (n=23). Attacks were unrelated to sleep stages, presence of apnea episodes, periodic limb movements, limb movements and arousals. In bout, patients had longer sleep latency (18.8 vs. 11.7min, P<0.05) and rapid eye movement sleep latency (1.7 vs. 1.2h, P<0.05) than controls and sleep efficiency was lower (82.5% vs. 86.5%, P<0.05). Patients in remission only had a longer sleep latency compared with controls (17.5 vs. 11.7min, P<0.01). The results support the presence of a continuing or slowly recovering disturbance of sleep outside the bout rather than a disturbance occurring secondary to attacks. Further, we confirm that there is no relation between CH attacks and specific sleep stages or between CH and breathing parameters.

Polysomnographic Findings in Patients With Chronic Tinnitus.

Tinnitus is an auditory sensation in the absence of any external stimulus. It has a negative impact on quality of life and interferes with concentration, sleep, social activities, and even emotional stability. The aim of this study was to compare sleep architecture in patients with and without chronic subjective tinnitus. This was an observational, noninterventional, and prospective study. The sample consisted of 50 individuals of both sexes aged 20 to 60 years. Twenty-five patients with tinnitus constituted the study group, and for comparison, a control group consisting of 25 patients without reported tinnitus was formed. The patients underwent polysomnography and were administered the Epworth Sleepiness Scale, Tinnitus Handicap Inventory, and visual analog scales. The group with tinnitus had higher mean values in sleep stages 1 and 2, and lower mean values in stage 3 and in rapid eye movement (REM) sleep, compared with the control group, and this difference was significant only for REM sleep ( P = .031). This demonstrates that patients with tinnitus remained longer in shallow sleep and spent less time in deep sleep (stage 3) and REM sleep. This study shows that patients with tinnitus have significant alterations in REM sleep latency as well as the REM sleep phase.

PO-019 Effects of Yin Yoga for Three Months on Insomnia in Menopausal Women

Objective To assess changes in sleep quality before and after 3 months Yin yoga on insomnia in menopausal women,which provides a scientific and reliable theoretical basis for improving insomnia of menopausal women by doing Yin yoga exercise.&#x0D; Methods Twenty menopausal women (year,48.16±3.66) with non-organic insomnia who volunteered for Yin yoga were selected. They all performed the same six poses of Yin yoga at 22:00 PM. Each pose lasted for 5min, 30 min each time, 5 times per week, and for 3 consecutive months. Before and after 3 month Yin yoga exercise, polysomnogram(PSG) and Pittsburgh sleep quality index (PSQI) were used to evaluate the improvement of insomnia.&#x0D; Results After 3 months Yin yoga exercise, the sleep latency (SL), rem sleep latency (RL) and sleep efficiency (SE) of the insomniacs all improved, with statistically significant differences (P&lt;0.05). Three months of Yin yoga exercise later, the Pittsburgh sleep quality index showed a significant difference in sleep scores compared with the start of exercise(P&lt;0.01).&#x0D; Conclusions Yin yoga exercise can improve insomnia in menopausal women and the effect is significant, worthy of promotion.

Abnormal Findings in Polysomnographic Recordings of Patients with Spinocerebellar Ataxia Type 2 (SCA2).

Spinocerebellar ataxia type 2 (SCA2) is characterized by a progressive cerebellar syndrome, and additionally saccadic slowing, cognitive dysfunction, and sleep disorders. The aim of this study was to assess the frequency of abnormal findings in sleep recordings of patients with SCA2. Seventeen patients with genetically confirmed SCA2 from the Movement Disorders Outpatient group of the Hospital de Clínicas da UFPR were evaluated with a structured medical interview and the Scale for the Assessment and Rating of Ataxia (SARA). Polysomnographic recordings were performed and sleep stages were scored according to standard criteria. There were 10 male subjects and 7 females, aged 24-66years (mean 47.44). A sex- and age-matched control group of healthy subjects was used for comparison. There was a reduction of rapid eye movement (REM) sleep in 12 (70.58%), increased REM latency in 9 (52.94%), increased obstructive sleep apnea-index in 14 (82.35%), absent REM density (REM density was calculated as the total number of 3-s miniepochs of REM sleep with at least 1 REM per minute) in 13 (76.47%), and markedly reduced REM density in 4 (23.52%). There was an indirect correlation according to the SARA scale and the REM density decrease (r = - 0.6; P = < 0.001); and with a disease progression correlating with a reduction in the REM density (r = - 0.52, P = 0.03). In SCA2, changes occur mainly REM sleep. The absence/decrease of REM sleep density, even in oligosymptomatic patients, and the correlation of this finding with disease time and with the SARA scale were the main findings of the study.

Respiratory-Related Leg Movements of Sleep Are Associated With Serotonergic Antidepressants But Not Bupropion.

Respiratory-related leg movements (RRLMs) may contribute to the cardiovascular risk associated with obstructive sleep apnea (OSA). Selective serotonin reuptake inhibitors (SSRIs), but not bupropion, increase periodic leg movements in sleep. This study examines whether patients with OSA using SSRIs have more RRLMs than those taking bupropion or no antidepressant. Patients with an apnea-hypopnea index (AHI) of at least 10 events/h during a full-night diagnostic study or split-night study, who were taking bupropion (n = 32), an SSRI (n = 31), or no antidepressant (n = 31), were selected from a database of prestudy questionnaires. RRLMs were scored according to World Association of Sleep Medicine 2016 standards. Patients using SSRIs had significantly greater overall RRLM% (defined as the percentage of respiratory events associated with a leg movement, including apneas, hypopneas, and respiratory effort-related arousals), RRLM index, and periodic limb movement index relative to patients using bupropion and control patients. The difference between the RRLM% in the SSRI and bupropion groups was limited to patients undergoing split-night studies, and that of the SSRI and control groups was limited to patients undergoing full-night diagnostic studies. The greater number of RRLMs and PLMs in the SSRI group may contribute to treatment-emergent insomnia often seen with SSRI use. Fragmented sleep and elevated autonomic nervous system activation associated with increased RRLMs in patients with OSA taking SSRIs might also limit the tolerability of antidepressant treatment, as well as increase the risk for cardiovascular disease.

HLA-DQB1*06:02 allele frequency and clinic-polysomnographic features in Saudi Arabian patients with narcolepsy.

Narcolepsy is an uncommon neurological disorder characterised by irresistible spells of sleep associated with abnormal rapid eye movement (REM) sleep. The association between narcolepsy and human leukocyte antigen HLA- DQB1*06:02 has been established elsewhere but remains to be investigated among Saudi Arabian patients with narcolepsy. A total of 29 Saudi patients with type I or type 2 narcolepsy comprising of 23 (79%) males and 6 (21%) females with a mean age of 17.2 ± 9.6years were included in this study. Type 1 or type 2 narcolepsy was diagnosed by full polysomnography followed by a multiple sleep latency test in accordance with International Classifications of Sleep Disorders-3 criteria. HLA typing for DQB1 alleles was performed by polymerase chain reaction and hybridization with sequence-specific oligonucleotide probes. Differences in clinical and sleep parameters were compared by univariable analyses. HLA-DQB1*06:02 frequency was systematically compared with the published literature. Type 1 narcolepsy was diagnosed in 19/29 (65.5%) patients, whereas 10/29 (34.5%) patients had type 2 narcolepsy. DQB1*06:02 was present in 25/29 (86.2%) patients; 15/19 (78.9%) narcolepsy type 1 patients and 10/10 (100%) narcolepsy type 2 patients harboured the DQB1*06:02 allele. REM latency was significantly lower in DQB1*06:02-positive patients compared to DQB1*06:02-negative patients (17.6 ± 32.3min vs. 106.0 ± 86.0min; p = 0.025). Epworth Sleepiness Scale scores were significantly higher among type 1 than type 2 narcolepsy patients (19.7 ± 3.2 vs 15.3 ± 3.6; p = 0.02). DQB1*06:02 allele frequencies among Saudi patients with narcolepsy were consistent with previously published data.

The impact of sleep characteristics and epilepsy variables on memory performance in patients with focal seizures

Disturbed sleep can negatively affect overnight memory retention as well as new learning the subsequent day. In healthy participants, positive associations between memory performance and sleep characteristics (e.g., time spent in slow-wave sleep [SWS]) have been detected. In a previous study, we found that SWS was much reduced in patients with focal seizures, but when correlations between memory complaints and various sleep characteristics were considered, the only significant relationship was with the time to onset of rapid eye movement (REM) sleep (i.e., REM latency). In this study, we investigated the relationships between sleep, epilepsy, and objective memory performance variables. Twenty-five patients with focal seizures had their memory tested while undergoing a two-day ambulatory electroencephalography (EEG). The sleep variables of interest were the percentage of time spent in SWS (%SWS) and REM latency. Epilepsy variables included the presence of (1) seizures, (2) interictal epileptiform discharges, and/or (3) hippocampal lesions as well as site of seizure origin (temporal vs extratemporal). Overnight retention (of autobiographical events, a story, and a complex geometric figure) and the ability to learn a word list on day 2 were the measures of memory. A significant positive correlation was found between word-list learning and %SWS during the previous night. A significant negative correlation was observed between REM latency and overnight retention of autobiographical events. Overnight retention scores for the story and geometric figure were not related to sleep characteristics but were negatively affected by the presence of epileptiform activity. Story retention was also worse for temporal lobe epilepsy (TLE) than for patients with extratemporal epilepsy (ETE). Those with hippocampal lesions were more impaired than those without lesions on word-list learning, autobiographical events' retention, and story retention. When multiple contributing factors were entered into regression analyses, %SWS was found to be the best predictor of subsequent word-list learning, whereas the presence of a hippocampal lesion was the best predictor of overnight retention of autobiographical events and a story. These findings provide further evidence of the ways in which particular sleep characteristics are associated with memory and suggest that treatment of sleep disturbances in patients with epilepsy might be helpful for improving their performance.

Sleep Disturbances Can Be Prospectively Observed in Patients with an Inactive Inflammatory Bowel Disease.

Poor sleep quality is associated with adverse health consequences. Sleep disturbances can impact the immune function and inflammatory processes. Little is known about sleep disturbances in patients with inflammatory bowel disease (IBD), while not in flare, i.e., inactive. To prospectively explore the sleep quality of patients with an inactive IBD. This pilot study included 36 consecutive patients with IBD and 27 healthy volunteers. All IBD patients had an inactive disease. Participants underwent an overnight ambulatory polysomnography. Data on disease duration, medications, complications, and treatment were collected from the medical records. The mean age of the IBD and the control groups was 39 ± 15 and 34.6 ± 9.6years. A significantly less rapid eye movement (REM) sleep was noted in the IBD group vs. control (23.7 vs. 27.8%, p = 0.047); light sleep percentage and REM latency were also longer in the IBD group. Moreover, oxygen desaturation below 90% was more common in the IBD group. All other sleep parameters including respiratory disturbance index, apnea-hypopnea index, number of wakes, sleep latency, and snoring strength were similar in both groups. Inactive IBD is associated with sleep disturbances. A larger prospective study should be conducted to confirm these findings.

Changes in Sleep Characteristics and Breathing Parameters During Sleep in Early and Late Pregnancy.

Few studies have objectively evaluated sleep characteristics during pregnancy or investigated the relationship between altered spectral electroencephalogram (EEG) bands and sleep-disordered breathing (SDB). The study aimed to describe changes in sleep as measured by polysomnography (PSG) and spectral EEG bands during pregnancy and to examine the relationship between delta power in non-rapid eye movement (NREM) sleep and SDB. This is a secondary analysis of a prospective study. One hundred twenty-three women underwent full PSG in early pregnancy, and 97 repeated PSG in late pregnancy. Spectral analysis of the EEG in NREM sleep was performed. We used linear and logistic mixed-model regression to analyze the sleep measures and linear regression to explore the association between delta power and apnea-hypopnea index (AHI) changes during pregnancy. In late pregnancy, women had shorter sleep duration, poorer sleep efficiency, more awakenings, more stage N2 sleep, less slow wave sleep, less REM sleep, higher AHI, and higher periodic limb movement index compared to early pregnancy. The percentage of stage N1 sleep, sleep latency, REM sleep latency, and arousal index frequency did not change. Regarding EEG-spectra, delta and theta powers decreased, but beta-2 power increased during pregnancy. In multivariable analyses, greater reduction of delta power was associated with larger increases in AHI (β [95% confidence interval] = -0.038 [-0.073, -0.002], P = .040). Estimates suggest that each one-unit increase in AHI reduces delta power by 4% in late pregnancy. PSG-measured sleep characteristics change during pregnancy. Delta power decreases when the severity of SDB increases during pregnancy. A commentary on this article appears in this issue on page 1095.

Research into an Association between Anhedonia and Decreased REM Latency in Moderately to Severely Depressed Patients.

Anhedonia stands as a core symptom and potential trait marker of major depressive disorder (MDD). The importance of rapid eye movement sleep latency (REML) as a biological marker of depression has previously and repeatedly been studied. The aim of this paper is to analyse the relationship between anhedonia and REML in moderately to severely depressed patients. The shortened Beck Depression Inventory (BDI-13) was chosen to assess depressive symptoms and, among them, more particularly, anhedonic symptoms. Two-way ANCOVA was used for statistical analyses. A significant association between anhedonic symptoms and REML was found when the number of sleep cycles (NCy) and the severity of depression were added as covariates. Our findings suggest that REML may be a useful variable to differentiate some diagnostic subtypes of depression related to anhedonia.

Human Rapid Eye Movement Sleep Shows Local Increases in Low-Frequency Oscillations and Global Decreases in High-Frequency Oscillations Compared to Resting Wakefulness.

It is often assumed that during rapid eye movement (REM) sleep the cerebral cortex homogenously shows electroencephalogram (EEG) activity highly similar to wakefulness. However, to date no studies have compared neural oscillatory activity in human REM sleep to resting wakefulness with high spatial sampling. In the current study, we evaluated high-resolution topographical changes in neural oscillatory power between both early and late naturalistic REM sleep and resting wakefulness in adult humans. All-night recordings with 256-channel high-density EEG (hd-EEG) were collected in healthy volunteers (N = 12). Topographic analysis revealed that, compared to wake, both the first and last cycle of REM sleep were associated with increased low-frequency oscillations in local central and occipital regions. In contrast, high-frequency activity in both α and β bands (8–20 Hz) was globally decreased during both early and late REM sleep cycles compared to wakefulness. No significant differences in topographic power in any frequency band were observed between REM sleep cycles occurring early and late in the night. We replicated these findings in an independent dataset (N = 33). Together, our findings show that human REM sleep shows consistent topographical changes in oscillatory power across both early and late sleep cycles compared to resting wakefulness.

Sleep patterns deteriorate over time in chronic corticosterone-treated rats

Repeated corticosterone (CORT) injections reliably produce depressive-like behavior in rodents. Our previous study showed that sleep parameters were altered in rats after daily injections of CORT for 7 days, and sleep disturbances appeared to be correlated with depressive-like behavior. The aim of the present study was to investigate time-dependent correlations between changes in sleep parameters and the formation of depressive-like behavior in rats after more prolonged treatment with CORT. Rats received daily injections of CORT (40 mg/kg, s.c.) for 7, 14, or 21 days. Electroencephalographic recordings were performed to study sleep parameters. The sucrose preference test and forced swim test were performed to evaluate depressive-like behavior. Western blot was used to detect protein levels. Our results showed that 7-day CORT treatment resulted in no significant depressive-like behavior or changes in rapid-eye-movement (REM) sleep. However, the duration of non-REM sleep significantly decreased, tyrosine hydroxylase (TH) levels significantly increased, and glucocorticoid receptor (GR) expression decreased in the locus coeruleus. Treatment with CORT for 14 and 21 days increased depressive-like behavior, enhanced REM sleep, shortened REM sleep latency, decreased TH and GR levels, and increased the levels of the chaperone FK506 binding protein 51 (FKBP51) in the locus coeruleus. These results indicate that the development of depression after chronic CORT treatment may be related to the formation of sleep disorders. Abnormalities of REM sleep may be a characteristic of sleep in models of depression that is induced by chronic CORT administration in rats. The noradrenergic system and GR pathway in the locus coeruleus may be involved in the formation of depression concomitant with sleep disturbances.

A Comparison of Two Nights of Ambulatory Sleep Testing in Arrhythmia Patients.

Introduction Obstructive sleep apnea (OSA) is common and usually underdetected in patients with cardiac arrhythmia. Ambulatory sleep testing may provide an alternative method for detection of OSA under realistic conditions compared to in-laboratory polysomnography. We aimed to (1) determine the sleep architecture in arrhythmia patients; (2) detect differences in sleep parameters between patients with and without OSA; and (3) compare the results of two consecutive nights of unattended ambulatory sleep testing. Methods Consecutive patients with unknown OSA status were recruited from arrhythmia clinics. Patients underwent two consecutive nights of self-applied in-home sleep testing replete with electroencephalogram (EEG) recording. Results One hundred patients were recruited. The mean age was 64 ± 13 years (70% males). OSA (AHI ≥ 5/h) was detected in 85% of patients. In the total sample, the sleep efficiency was reduced, and sleep onset latency was longer compared to a reference population of the same age. In patients with OSA, the sleep efficiency and the percentage of slow wave sleep were reduced; however, the arousal and periodic limb movement indices were increased compared to patients without OSA. The two nights of the ambulatory sleep testing showed consistent results with an excellent test-retest reliability for the AHI (ICC = 0.813). REM latency was shorter during the second night of sleep recording (p = 0.02). There were no other significant differences in the sleep architecture, respiratory indices, and other sleep parameters between the first and the second night of the ambulatory sleep recording. Conclusions There is no significant difference in the respiratory parameters obtained during two consecutive nights of ambulatory sleep testing. Ambulatory studies incorporating EEG may provide a reliable, convenient, and economically efficient method for sleep assessment and there appears to be no significant night-to-night variability.

S75. Polysomnographic parameters and their computed tomography brain morphology correlates in depression

Introduction Sleep in depression is characterized by a reduction of slow wave sleep (SWS) and shortening of the interval between sleep onset and the occurrence of the first REM period (i.e. REM latency). In this study, the authors sought to study and compare the polysomnographic patterns in patients with major depressive disorder and their first degree relatives and also to establish any correlation between sleep parameters and brain ventricular system measurements in patients with depression. Methods In this study, patients (N = 15) with ICD-10 clinical diagnosis of unipolar depression (N = 7) or recurrent depressive disorder (N = 8) along with their first degree male relatives (N = 15) and normal controls (N = 15) were enrolled. All the participants underwent two nights of polysomnography. The polysomnographic data was collected and analyzed using the Sandman Elite Polysomnography System. Computed Tomography was used for neuroimaging of brain. Results Significant difference was observed between the three groups in terms of total sleep period, sleep onset latency, stage 1 latency, REM duration, REM percentage of total sleep time and REM latency. Ventricular brain ratio (VBR) was found to be significantly more in the patient group (7.26 ± 1.55) and Bicaudate ratio (BCR) showed significantly more in patients group (0.140 ± 0.047). Bifrontal ratio was also observed to be significantly more in the patient group. Conclusion This study failed to find any correlation between polysomnographic parameters and ventricular dysmorphology.

Sleep architecture and epileptic characteristics of drug naïve patients in childhood absence epilepsy spectrum. A prospective study

PurposeChildhood absence epilepsy (CAE) is an epileptic syndrome presenting between 2nd–10th years. The spells are elicited with hyperventilation (HV) while sleep seems to exacerbate the electrical activity. Our aim is to describe sleep architecture and its relationship with epileptic discharges (EDs) in patients with CAE, before treatment and one year later. MethodsTwenty-eight, drug-naive children were recruited (21 girls), mean age 90.1 ± 32.6 months. Routine-EEG and overnight EEG-polygraphy were conducted upon diagnosis and one year later. Patients were separated in two groups of similar mean age, according to their clinical response at the second recording: group A: children with absolute control of absences and group B: children with partial control. Sleep parameters, EDs and arousals were measured. The effect of medication on sleep parameters was examined, according to 2 groups: valproic-treated and non valproic-treated. ResultsGroup A showed significant improvement in total sleep time, REM-sleep latency, REM-sleep, arousals-number/hour and arousals-duration/hour between the two recordings. Comparing the two groups for each recording separately, group A initially demonstrated greater epileptic activity and worse sleep parameters, whereas in the second recording exhibited total elimination of the EDs and significantly less arousals. Group B demonstrated persisting EDs and slight deterioration in some sleep parameters during the second recording, despite the lower epileptic load initially. No significant difference was identified between valproic and non-valproic treated patients, regarding the effect on sleep parameters. ConclusionAbsolute control of absences and normalization of the electroencephalogram are accompanied by more continuous, stable and efficacious sleep in children with CAE.

Investigation and Analysis of Sleep Status in Patients with Vascular Depression

Summary Background To investigate the sleep status of patients with vascular depression (VD) and analyze the characteristics of sleep by polysomnogram. Methods 50 VD patients, 30 patients with non-vascular depression (NVD) and 50 normal subjects were enrolled. All subjects were evaluated by the Hamilton Depression Rating Scale (HAM-D), Hamilton Anxiety Scale (HAM-A), Pittsburgh Sleep Quality Index (PSQI) and Epworth sleepiness scale (ESS). All these patients were monitored by polysomnography (PSG). Results The PSQI scores of the VD patients didn't show difference compared with that of NVD, but both of them were significantly higher than the normal. The ESS scores of VD patients were significantly higher than other groups. The total sleep time (TST), sleep efficiency (SE) and sleep maintenance (SMT) in NVD patients and VD patients were poorer, and the waking time after sleep onset (WASO) and sleep latency (SL) were significantly longer. The N1/N2 ratio was longer, and the N3/REM ratio was shorter in NVD patients and VD patients. The HAMD score was negatively correlated with RL and positively with RD, RA and RI. The RL of VD patients was longer than the normal, and RD and RI were higher in VD patients, there was no difference in RA. The obstructivity and apnea-hypopnea index (AHI) significantly increased in VD patients. Conclusion The characteristic PSG findings of the NVD patients were shortening REM sleep latency and REM disinhibition. Characteristics of VD with PSG patients were sleep-related breathing disorders (SRBD) and daytime sleepiness, and disorders of 24-h sleep structure.

Nightmares in United States Military Personnel With Sleep Disturbances

Sleep disturbances are common in United States military personnel. Despite their exposure to combat and trauma, little is known about nightmares in this population. The purpose of this study was to describe the prevalence and associated clinical and polysomnographic characteristics of nightmares in United States military personnel with sleep disturbances. Retrospective review of 500 active duty United States military personnel who underwent a sleep medicine evaluation and polysomnography at our sleep center. The Pittsburgh Sleep Quality Index and the Pittsburgh Sleep Quality Index-Addendum were used to characterize clinically significant nightmares. Subjective and objective sleep attributes were compared between groups. At least weekly nightmares were present in 31.2%; yet, only 3.9% reported nightmares as a reason for evaluation. Trauma-related nightmares occurred in 60% of those patients with nightmares. Patients with nightmares had increased sleep onset latency (SOL) and rapid eye movement (REM) sleep latency (mean SOL/REM sleep latency 16.6/145 minutes, P = .02 and P = .01 respectively) compared to those without (mean SOL/REM sleep latency 12.5/126 minutes). The comorbid disorders of depression (P ≤ .01, relative risk [RR] 3.55 [95% CI, 2.52-4.98]), anxiety (P ≤ .01, RR 2.57 [95% CI, 1.93-3.44]), posttraumatic stress disorder (P ≤ .01, RR 5.11 [95% CI, 3.43-7.62]), and insomnia (P ≤ .01, RR 1.59 [95% CI, 1.42-1.79]) were all associated with nightmares. Clinically significant nightmares are highly prevalent in United States military personnel with sleep disturbances. Nightmares are associated with both subjective and objective sleep disturbances and are frequently comorbid with other sleep and mental health disorders. A commentary on this article appears in this issue on page 303.