Clinical manifestations of Parkinson disease and the onset of rapid eye movement sleep behavior disorder

ObjectiveTo identify whether the presence and/or timing of rapid eye movement (REM) sleep behavior disorder (RBD) onset were associated with differences in clinical features and sleep parameters of Parkinson disease (PD).MethodsIn all, 112 PD patients were enrolled and all underwent extensive clinical evaluations and video-polysomnography (PSG). Clinical features and PSG parameters were compared in PD patients with (PD + RBD) or without (PD − RBD) RBD, RBD preceding (RBD > PD), or not (PD ⩾ RBD) PD onset.ResultsSixty-three of the 112 PD patients were affected by RBD. Adjusted for age, gender, education, body mass index (BMI), levodopa equivalent daily dose (LED) and PD duration, PD + RBD patients had higher Hoehn & Yahr stage, higher scores for UPDRS parts I, II and III, more dyskinesia, higher ratio of axial/limb manifestations, and more hallucinations. Their cognitive and quality-of-life status was significantly lower (all P < 0.05). For PSG, PD + RBD patients exhibited higher percentages of phasic and tonic EMG activities, lower apnea hypopnea (AHI) and oxygen desaturation index (ODI), and less time in arterial oxygen saturation (SaO₂) <90% during REM sleep (all P < 0.05). PD ⩾ RBD (n = 22) patients did not significantly differ from RBD > PD (n = 41) patients in clinical manifestations, whereas the PD ⩾ RBD subgroup had significantly higher UPDRS part I score, lower PDQ score and lower AHI during REM than the PD − RBD group (all P < 0.05), but not RBD > PD subgroup. Correlation analysis showed that worse cognition was associated with shorter interval of RBD preceding PD onset (r = 0.297, P = 0.018), but not RBD duration (P = 0.202).ConclusionsClinical manifestations of PD may vary depending on the presence and timing of RBD onset. These findings are compatible with the hypothesis that RBD may be a marker of complex subtypes of PD.     

The sleep macroarchitecture of children at risk for depression recruited in sleep centers

ObjectiveThe primary aim of this study was to compare the sleep macroarchitecture of children and adolescents whose mothers have a history of depression with children and adolescents whose mothers do not.MethodPolysomnography (PSG) and Holter electroencephalogram (EEG) were used to compare the sleep architecture of 35 children whose mothers had at least one previous depressive episode (19 boys, aged 4–18 years, “high-risk” group) and 25 controls (13 males, aged 4–18 years, “low-risk” group) whose mothers had never had a depressive episode. The total sleep time, wakefulness after sleep onset (WASO), sleep latency, sleep efficiency, number of awakenings per hour of sleep, percentages of time spent in each sleep stage, rapid eye movement (REM) latency and the depressive symptoms of participants were measured.ResultsIn children (4–12 years old), the high-risk group exhibited significantly more depressive symptoms than controls (P = 0.02). However, PSG parameters were not significantly different between high-risk children and controls. In adolescents (13–18 years old), the high-risk subjects presented with significantly more depressive symptoms (P = 0.003), a significant increase in WASO (P = 0.019) and a significant decrease in sleep efficiency compared to controls (P = 0.009).ConclusionThis study shows that children and adolescents born from mothers with a history of at least one depressive episode had significantly more depressive symptoms than controls. However, only high-risk adolescents presented with concurrent alterations of sleep macroarchitecture.     

The importance of polysomnography in the evaluation of prolonged disorders of consciousness: sleep recordings more adequately correlate than stimulus-related evoked potentials with patients’ clinical status

ObjectivesThe aim of our study was to evaluate the importance of sleep recordings and stimulus-related evoked potentials (EPs) in patients with prolonged disorders of consciousness (DOCs) by correlating neurophysiologic variables with clinical evaluation obtained using specific standardized scales.MethodsThere were 27 vegetative state (VS) and 5 minimally conscious state (MCS) patients who were evaluated from a clinical and neurophysiologic perspective. Clinical evaluation included the Coma Recovery Scale-Revised (CRS-R), Disability Rating Scale (DRS), and Glasgow Coma Scale (GCS). Neurophysiologic evaluation included 24-h polysomnography (PSG), somatosensory EPs (SEPs), brainstem auditory EPs (BAEPs), and visual EPs (VEPs).ResultsPatients with preservation of each single sleep element (sleep–wake cycle, sleep spindles, K-complexes, and rapid eye movement [REM] sleep) always showed better clinical scores compared to those who did not have preservation. Statistical significance was only achieved for REM sleep. In 7 patients PSG showed the presence of all considered sleep elements, and they had a CRS-R score of 8.29 ± 1.38. In contrast, 25 patients who lacked one or more of the sleep elements had a CRS-R score of 4.84 ± 1.46 (P < .05). Our multivariate analysis clarified that concurrent presence of sleep spindles and REM sleep were associated with a much higher CRS-R score (positive interaction, P < .0001). On the other hand, no significant associations were found between EPs and CRS-R scores.ConclusionsPSG recordings have proved to be a reliable tool in the neurophysiologic assessment of patients with prolonged DOCs, correlating more adequately than EPs with the clinical evaluation and the level of consciousness. The main contribution to higher clinical scores was determined by the concomitant presence of REM sleep and sleep spindles. PSG recordings may be considered inexpensive, noninvasive, and easy-to-perform examinations to provide supplementary information in patients with prolonged DOCs.     

Functional neuronal activity and connectivity within the subthalamic nucleus in Parkinson’s disease

ObjectiveCharacterization of the functional neuronal activity and connectivity within the subthalamic nucleus (STN) in patients with Parkinson’s disease (PD).MethodsSingle units were extracted from micro-electrode recording (MER) of 18 PD patients who underwent STN deep brain stimulation (DBS) surgery. The firing rate and pattern of simultaneously recorded spike trains and their coherence were analyzed. To provide a precise functional assignment of position to the observed activities, for each patient we mapped its classified multichannel STN MERs to a generic atlas representation with a sensorimotor part and a remaining part.ResultsWithin the sensorimotor part we found significantly higher mean firing rate (P < 0.05) and significantly more burst-like activity (P < 0.05) than within the remaining part. The proportion of significant coherence in the beta band (13–30 Hz) is significantly higher in the sensorimotor part of the STN than elsewhere (P =  0.015).ConclusionsThe STN sensorimotor part distinguishes itself from the remaining part with respect to beta coherence, firing rate and burst-like activity and postoperatively was found as the preferred target area.SignificanceOur firing behavior analysis may help to discriminate the STN sensorimotor part for the placement of the DBS electrode.     

Association between body mass index and sleep duration assessed by objective methods in a representative sample of the adult population

IntroductionSleep duration has been associated with overweight individuals in many epidemiological studies; however, few studies have assessed sleep using objective methods. Our study was designed to evaluate the association between body mass index (BMI) and sleep duration measured by actigraphy (Acti), polysomnography (PSG) and the Pittsburgh Sleep Quality Index questionnaire (PSQIO). Furthermore, we evaluated other biochemical and polysomnographic parameters.MethodsA representative sample of 1042 individuals from Sao Paulo, Brazil, including both genders (20–80 yrs), participated in our protocol. Weight and other anthropometric parameters were measured at the onset of the study. Sleep duration was calculated by Acti, PSG, and the PSQIQ. The population was sorted by sleep duration, body, slow wave sleep (SWS) and REM sleep (REMS) duration subsets. In addition, other biochemical and polysomnographic parameters were analyzed. Differences between population subsets were analyzed by one-way analysis of variance (ANOVA). Linear regression analysis was performed between sleep and anthropometric parameters.ResultsShorter sleep duration was associated with higher BMI and waist and neck circumference when measured by Acti and PSG (p < 0.05). Lower leptin levels were associated with short sleep in normal-weight (BMI > 18 and ⩽25) individuals (p < 0.01). The association between short sleep duration Acti and higher BMI was present when apnea-hypopnea index (AHI) was less than 15 (p = 0.049). Shorter REMS and SWS also were associated with higher BMI (p < 0.01). Normal-weight individuals tended to sleep longer, have higher sleep efficiency and longer SWS and REMS than obese individuals (Acti, PSG; p = 0.05). Sleep duration was negatively correlated with BMI (Acti, PSG; p < 0.05). Short SWS and REMS were associated with higher cardiovascular risk factors (p < 0.05).ConclusionShorter sleep, SWS, and REMS duration were associated with higher BMI, central adiposity measurements, and cardiovascular risk factors when measured by objective methods.     

Smoking and sleep disorders in Chinese adolescents

ObjectiveTo investigate the association between adolescent smoking and sleep disorders.MethodsIn the Hong Kong student obesity surveillance project, 29,397 Chinese students, aged 12–18 years, completed a health survey. Insomnia was defined as having any of the following three symptoms: difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS) and early morning awakening (EMA). The presence of snoring and difficulty breathing during sleep (DBS) was also reported. Logistic regression yielded adjusted odds ratios (ORs) for each sleep disorder by smoking status.ResultsCompared with never smokers, the ORs (95% CI) of insomnia were 1.39 (1.25–1.54) for experimenters (smoked once or a few times) and 0.91 (0.83–1.00) for current smokers. The corresponding ORs were 1.42 (1.16–1.74) and 3.58 (3.15–4.06) for snoring (P for trend < 0.001) and 1.40 (1.10–1.79) and 3.39 (2.97–4.03) for DBS (P for trend < 0.001). Current smokers compared with never smokers were less likely to report DIS (OR = 0.43, 95% CI = 0.38–0.50, P < 0.001) and EMA (OR = 0.83, 95% CI = 0.73–0.94, P = 0.003), but more likely to report DMS (OR = 1.45, 95% CI = 1.28–1.63, P < 0.001).ConclusionsIn terms of dosage, adolescent smoking was associated with snoring and DBS, with increasing ORs from never smokers to experimental and current smokers. Current smoking was associated positively with DMS, but negatively with DIS and EMA.     

Decreased sleep spindle density in patients with idiopathic REM sleep behavior disorder and patients with Parkinson’s disease

ObjectiveTo determine whether sleep spindles (SS) are potentially a biomarker for Parkinson’s disease (PD).MethodsFifteen PD patients with REM sleep behavior disorder (PD + RBD), 15 PD patients without RBD (PD − RBD), 15 idiopathic RBD (iRBD) patients and 15 age-matched controls underwent polysomnography (PSG). SS were scored in an extract of data from control subjects. An automatic SS detector using a Matching Pursuit (MP) algorithm and a Support Vector Machine (SVM) was developed and applied to the PSG recordings. The SS densities in N1, N2, N3, all NREM combined and REM sleep were obtained and evaluated across the groups.ResultsThe SS detector achieved a sensitivity of 84.7% and a specificity of 84.5%. At a significance level of α = 1%, the iRBD and PD + RBD patients had a significantly lower SS density than the control group in N2, N3 and all NREM stages combined. At a significance level of α = 5%, PD − RBD had a significantly lower SS density in N2 and all NREM stages combined.ConclusionsThe lower SS density suggests involvement in pre-thalamic fibers involved in SS generation. SS density is a potential early PD biomarker.SignificanceIt is likely that an automatic SS detector could be a supportive diagnostic tool in the evaluation of iRBD and PD patients.     

Lack of differential motor outcome with subthalamic nucleus region stimulation in Parkinson’s disease

Deep brain stimulation (DBS) has emerged as a viable therapy for Parkinson’s disease (PD). The impact of subthalamic nucleus (STN) lead placement (lateral versus medial) on motor outcome, however, has not been systematically evaluated. Forty-eight patients with PD underwent STN-DBS surgery and were evaluated postoperatively for 48 weeks for motor improvement as measured by the Unified Parkinson’s Disease Rating Scale (UPDRS) part III (standardized motor examination) and levodopa equivalent daily dose (LEDD). Postoperative MRI was used to identify the location of the active stimulating contact and motor outcome was analyzed. STN-DBS was associated with significant improvement in motor outcome as determined by a reduction in the UPDRS part III subscore from 34.44 ± 1.29 at baseline to 18.76 ± 1.06 at end visit (p < 0.0001) and a reduction in LEDD from 1721 ± 152 mg/day at baseline to 1134 ± 119 mg/day at end visit (p = 0.0024). Patients with stimulating contacts in the medial STN compared to the lateral STN did not demonstrate any significant differences in motor outcome (UPDRS, p = 0.5811; LEDD, p = 0.7341). No significant differences were found in motor outcome between patients with STN stimulation compared to stimulation of surrounding fiber tracts (p = 0.80). No significant difference in stimulation voltage was noted with respect to lead location. Our study did not find a significant effect for the location of active contact and motor outcome neither within the subregions of the STN nor between the STN and surrounding fibers. Further research is needed to better understand the neurophysiological basis for these results.     

Degree of pineal calcification (DOC) is associated with polysomnographic sleep measures in primary insomnia patients

ObjectiveMelatonin plays a key role in the proper functioning of the circadian timing system (CTS), and exogenous melatonin has been shown to be beneficial in cases of CTS and sleep disturbances. Nevertheless, the concept of “melatonin deficit” has yet to be defined. The aim of our study was, therefore, to determine the relationship between the degree of pineal calcification (DOC) and a range of sleep parameters measured objectively using polysomnography (PSG).MethodsA total of 31 outpatients (17 women, 14 men, mean age 45.9 years; SD 14.4) with primary insomnia were included in our study. Following an adaptation night, a PSG recording night was performed in the sleep laboratory. Urine samples were collected at predefined intervals over a 32-h period that included both PSG nights. The measurement of 6-sulphatoxymelatonin (aMT6s) levels was determined using ELISA. DOC and volume of calcified pineal tissue (CPT) and uncalcified pineal tissue (UPT) were estimated by means of cranial computed tomography.ResultsUPT was positively associated with 24-h aMT6s excretion (r = 0.569; P = 0.002), but CPT was not. After controlling for age, aMT6s parameters, CPT, and UPT did not correlate with any of the PSG parameters evaluated. In contrast, DOC was negatively associated with REM sleep percentage (r = ?0.567, P = 0.001), total sleep time (r = ?0.463, P = 0.010), and sleep efficiency (r = ?0.422, P = 0.020).ConclusionDOC appears to be a superior indicator of melatonin deficit compared to the absolute amount of melatonin in the circulation. High DOC values indicate changes predominantly in the PSG parameters governed by the circadian timing system. DOC may thus serve as a marker of CTS instability.     

Sleep disturbances in Malaysian patients with Parkinson's disease using polysomnography and PDSS

BackgroundSleep disturbances such as sleep fragmentation, sleep disordered breathing (SDB), periodic limb movements (PLM), excessive daytime somnolence (EDS) and insomnia are prevalent in Parkinson's disease (PD). However, studies in the Asian population are limited.MethodsThis was a cross-sectional study involving 46 Malaysians with PD using polysomnography (PSG) and standardized translated Parkinson's disease sleep scale (PDSS). Overnight PSG recordings, UPDRS and PDSS scores, and baseline demographic data were obtained.ResultsData from 44 patients were analysed. Thirty-six patients (81.8%) had PSG-quantified sleep disorders. Twenty-three (52.3%) had sleep fragmentation, 24 (54.6%) had SDB and 14 (32%) had PLM. EDS was present in 9.1%. Insomnia was reported by 31.8%. Patients with sleep fragmentation had significantly higher UPDRS scores and lower PDSS insomnia sub-scores. The UPDRS scores correlated negatively with the TST and sleep efficiency. All patients with EDS had SDB (p = 0.056). The PDSS insomnia sub-items correlated with sleep fragmentation on PSG.Conclusion: The prevalence of sleep disorders based on PSG and PDSS in our PD patients was high, the commonest being sleep fragmentation and SDB, while EDS was the least prevalent. Problem specific sub-items of the PDSS were more accurate in predicting the relevant PSG-related changes compared to the PDSS as a whole.     

Weight changes associated with unilateral STN DBS and advanced PD

Weight gain following bilateral subthalamic nucleus deep brain stimulation (STN DBS) in Parkinson disease (PD) has been characterized previously, but little is known about changes in weight following unilateral STN DBS. Weight gain of approximately 10 kg at one year after bilateral STN DBS for PD has been noted in previous studies, and PD in the absence of DBS has been associated with weight loss. A case-control comparison evaluated the change in weight following unilateral STN DBS in PD. In 39 patients who underwent unilateral STN DBS for PD, we measured the weight change over 1 year versus both preoperative weight change and the weight change in 40 age- and disease severity-matched PD controls without DBS. Regression analyses incorporating age, gender, baseline weight in case or control were conducted to assess weight changes. At 12 months following surgery, the mean weight of unilateral STN DBS patients increased by 4.3 ± 7.2 kg versus the preoperative baseline weight (p < 0.001) and this increase was 4.8 kg compared with the controls (p = 0.015). Over a 1 year time interval, weight gain occurred in 41% of the preoperative unilateral STN DBS patients and 45% of the PD controls, while 85% of the unilateral STN DBS patients had gained weight at 12 months after surgery (p < 0.0001, respectively, chi square test). We conclude that unilateral STN DBS in PD is associated with weight gain, which offsets weight loss associated with advanced PD.     

Excessive fragmentary myoclonus in Machado–Joseph disease

ObjectiveMachado–Joseph disease (MJD) is a neurodegenerative disease which usually presents several clinical findings including cerebellar ataxia and other extracerebellar features, such as Parkinsonism, dystonia, peripheral neuropathy, and lower motor neuron disease. Some data have demonstrated a high frequency of sleep disorders in these patients, including excessive daytime sleepiness (EDS), insomnia, obstructive sleep apnea (OSA), rapid eye movement (REM) sleep behavior disorder (RBD), and restless legs syndrome (RLS). Herein, we aimed to describe the high frequency of excessive fragmentary myoclonus (EFM) in MJD.Materials and methodsWe recruited 44 patients with MJD and 44 healthy controls. All participants underwent an all-night polysomnography (PSG). EFM was evaluated and defined in accordance to the criteria of the American Academy of Sleep Medicine.ResultsHalf of the MJD patients (n = 22) had EFM diagnosed through PSG, though no healthy control participant presented this finding (P < .0001). In the MJD group, older participants and men had a higher frequency of EFM. There was no correlation between EFM and the following data: body mass index (BMI), apnea–hypopnea index (AHI), EDS, loss of atonia during REM sleep, periodic limb movements during sleep (PLMS), RLS, RBD, ataxia severity, the number of cytosine–adenine–guanine trinucleotide (CAG) repeats, disease duration, sleep efficiency, sleep fragmentation, and sleep stage percentages between patients with or without EFM.ConclusionEFM is highly prevalent in patients with MJD. Our study demonstrates that EFM must be included in the clinical spectrum of sleep disorders in MJD patients.     

The effect of childhood obstructive sleep apnea on ambulatory blood pressure is modulated by the distribution of respiratory events during rapid eye movement and nonrapid eye movement sleep

ObjectiveWe aimed to investigate if different childhood obstructive sleep apnea (OSA) subtypes, namely rapid eye movement (REM)-related, nonrapid eye movement (NREM)-related and stage-independent OSA would exert different effects on ambulatory blood pressure (ABP).MethodsData from our previous school-based cross-sectional study were reanalyzed. Subjects who had an obstructive apnea–hypopnea index (OAHI) between 1 and 10 events per hour and a total REM sleep duration of >30 min were included in our analysis. REM-related and NREM-related OSA were defined as a ratio of OAHI in REM sleep (OAHI_REM) to OAHI in NREM sleep (OAHI_NREM) of >2 and <0.5, respectively. The others were classified as stage-independent OSA.ResultsA total of 162 subjects were included in the analysis. In the mild OSA (OAHI, 1–5 events/h) subgroup, no significant differences in any ABP parameters were found between OSA subtypes. On the other hand, in subjects with moderate OSA (OAHI, 5–10 events/h), the REM-related OSA subtype had a significantly lower daytime systolic blood pressure (SBP) z score (−0.13 ± 0.90 cf 1.15 ± 0.67; P = .012) and nighttime SBP z score (0.29 ± 1.06 cf 1.48 ± 0.88, P = .039) than the stage-independent OSA subtype. Linear regression analyses revealed that OAHI_NREM but not OAHI_REM was significantly associated with both daytime (P = .008) and nighttime SBP (P = .042) after controlling for age, gender, and body size.ConclusionChildren with obstructive events mainly in REM sleep may have less cardiovascular complications than those with stage-independent OSA.     

Insomnia symptoms,objectively measured sleep,and disease severity in chronic obstructive pulmonary disease outpatients

BackgroundSleep disturbances are known to have a negative impact on a range of clinical outcomes in chronic obstructive pulmonary disease (COPD). We examined the associations of insomnia symptoms and objectively measured sleep parameters to a composite score for body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index (a multidimensional index of COPD severity), arterial blood gases, nocturnal respiratory disturbances, periodic limb movements (PLM), psychologic distress, pain, age, and sex.MethodsThe sample comprised 73 COPD outpatients (mean age, 63.6 years; standard deviation {SD}, 7.5; range 47–85 years; 41.1% women). Insomnia symptoms were measured with the Bergen Insomnia Scale (BIS) and sleep efficiency (SE), slow-wave sleep (SWS), and total sleep time (TST) were assessed with clinical polysomnography (PSG).ResultsBODE index was positively associated with composite BIS score (P = .040). Patients with more severe COPD presented more complaints of nonrestorative sleep compared to patients with less severe COPD (P = .010). In multivariate analysis, the composite BIS score was independently associated with PLM (P < .001), nocturnal respiratory disturbances (P = .001), pain (P = .031), and psychologic distress (P = .044) but not with the BODE index. Objectively measured sleep variables were not associated with any of the health-related variables.ConclusionInsomnia symptoms in COPD patients result from a wide range of health-related factors. More severe COPD may be associated with a subjective experience of nonrestorative sleep but not with objectively measured sleep variables.     

Effect of successful epilepsy surgery on subjective and objective sleep parameters – a prospective study

ObjectiveTo evaluate the effect of surgery on subjective and objective measures of sleep quality among patients with medically refractory focal epilepsy.MethodsIn a prospective cohort study, patients with medically refractory epilepsy undergoing epilepsy surgery were recruited. All patients were assessed seven days pre- and three months post-surgery in terms of history pertaining to epilepsy and sleep, Epworth sleepiness score (ESS), one week sleep log and over night polysomnography (PSG).ResultsAmong 17 patients (mean age 18, 11 males), seizure frequency had reduced (p = 0.04) and self reported sleep parameters had significantly improved (reduced total duration of night time sleep, regularity on one week sleep log and ESS (p < 0.05)) three months following epilepsy surgery. Patients with good surgical outcome (n = 12) showed reduced seizure frequency (p = 0.01) and reduced ESS with corresponding reduction in arousal index (AI) (p = 0.02) and increase in total sleep time (p = 0.03), postoperatively. Three patients in the good surgical outcome group showed reduction in apnea–hypopnea index (AHI) from more than five to less than five. There was no significant change either in seizure frequency, self reported clinical parameters or PSG parameters among patients with poor surgical outcome.ConclusionEpilepsy surgery improves subjective sleep parameters in patients with medically refractory epilepsy during the early post operative period. Successful epilepsy surgery may improve objective (PSG documented) sleep quality, sleep architecture and obstructive sleep apnea with resultant reduction in excessive daytime sleepiness.     

A randomized placebo-controlled polysomnographic study of eszopiclone in Japanese patients with primary insomnia

ObjectivesTo evaluate the efficacy and dose–response effect of eszopiclone on sleep latency and sleep maintenance in Japanese patients with primary insomnia.MethodsIn this randomized, double-blind, five-way crossover study, 72 patients received placebo, eszopiclone 1 mg, 2 mg, and 3 mg, and zolpidem 10 mg in random order for two consecutive nights with a washout period between treatments. Objective sleep measures from polysomnography (PSG) and subjective patient reports were collected.ResultsAll active treatments produced significant improvement in objective and subjective sleep latency compared with placebo (P < 0.05 for all comparisons); linear dose–response relationships were observed for eszopiclone. PSG-determined wake time after sleep onset (WASO), sleep efficiency, and number of awakenings (NA), and patient-reported measures of WASO, NA, sleep quality, sleep depth, and daytime functioning significantly improved following treatment with eszopiclone 2 mg and 3 mg and zolpidem 10 mg versus placebo (P < 0.05). Eszopiclone at all doses increased total sleep time and stage 2 sleep time (P < 0.001 for both comparisons), but did not alter REM or slow-wave sleep. Eszopiclone was generally well tolerated; the most frequently reported adverse event was mild dysgeusia.ConclusionsIn Japanese patients with primary insomnia, eszopiclone 2 mg and 3 mg significantly improved PSG-determined and patient-reported sleep latency and sleep maintenance relative to placebo.     

Objective sleep interruption and reproductive hormone dynamics in the menstrual cycle

ObjectivesWomen report greater sleep disturbance during the premenstrual phase of the menstrual cycle and during menses. However, the putative hormonal basis of perceived menstrual cycle-related sleep disturbance has not been investigated directly. We examined associations of objective measures of sleep fragmentation with reproductive hormone levels in healthy, premenopausal women.MethodsTwenty-seven women with monthly menses had hormone levels measured at two time points during a single menstrual cycle: the follicular phase and the peri-ovulatory to mid-luteal phase. A single night of home polysomnography (PSG) was recorded on the day of the peri-ovulatory/mid-luteal-phase blood draw. Serum progesterone, estradiol, and estrone levels concurrent with PSG and rate of change in progesterone (PROGslope) from the follicular blood draw to PSG were correlated with log-transformed wake after sleep onset (lnWASO%) and number of wakes/hour of sleep (lnWake-Index) using linear regression.ResultsSleep was more fragmented in association with a steeper PROGslope (lnWASO% p = 0.016; lnWake-Index p = 0.08) and higher concurrent estrone level (lnWASO% p = 0.03; lnWake-Index p = 0.01), but the effect of estrone on WASO was lost after accounting for PROGslope. WASO% and Wake-Index were not associated with concomitant progesterone or estradiol levels.ConclusionsA steeper rate of rise in progesterone levels from the follicular phase through the mid-luteal phase was associated with significantly greater WASO, establishing a link between reproductive hormone dynamics and sleep fragmentation in the luteal phase of the menstrual cycle.     

REM sleep characteristics of nightmare sufferers before and after REM sleep deprivation

ObjectivesTo examine whether disrupted regulation of REM sleep propensity is implicated in nightmare (NM) pathophysiology.BackgroundHeightened REM propensity induced by REM sleep deprivation is belied by increases in REM %, REM density and the dreamlike quality of dream mentation during post-deprivation recovery sleep. Compromised regulation of REM sleep propensity may be a contributing factor in the pathophysiology of frequent NMs.MethodsA preliminary study of 14 subjects with frequent NMs (?1 NM/week; 27.6 ± 9.9 years) and 11 healthy control subjects (<1 NM/month; 24.3 ± 5.3 years) was undertaken. Subjects completed home sleep/dream logs and underwent three nights of polysomnographic recording with REM sleep deprivation on night 2. Group differences were assessed for a battery of REM sleep and dream measures on nights 1 and 3.ResultsSeveral measures, including #skipped early-night REM periods, REM latency, REM/NREM cycle length, early/late REM density,REM rebound, late-night REM% and dream vividness, suggested that REM sleep propensity was abnormally low for the frequent NM group throughout the 3-day study.ConclusionsFindings raise the possibility that REM anomalies recorded from NM sufferers sleeping in the laboratory environment reflect a disruption of one or more endogenous regulators of REM sleep propensity.     

Susceptibility to life-threatening ventricular arrhythmias in an animal model of paradoxical sleep deprivation

BackgroundAccording to some reports regarding the increase of cardiac events following sleep deprivation, our study was conducted to clarify the effects of rapid eye movement (REM) sleep deprivation on susceptibility to lethal ventricular arrhythmias in rat.MethodsThe animal groups included the control group; the sham 48 and sham 72 groups (without sleep deprivation); and the test 48 and test 72 groups, who experienced REM sleep deprivation for 48 h and 72 h, respectively. For induction of cardiac arrhythmia, aconitine was infused via the tail vein of the animals.ResultsAfter 72 h of REM sleep deprivation, the blood pressure (BP) levels and the QTc interval of the electrocardiogram (ECG) were significantly increased (P < .05 and P < .01, respectively). However, the sleep deprivation had no significant effect on the heart rate (HR), myocardial oxygen consumption index, and plasma corticosterone level. Furthermore, sleep deprivation increased the latency times of premature ventricular contraction (PVC), ventricular tachycardia (VT), and also the PVC number; however, it did not increase the number, duration, and severity of VT and ventricular fibrillation (VF).ConclusionOur findings suggest that 72 h of REM sleep deprivation is associated with increased risk for hypertension and QT interval prolongation under nonstressful conditions; however, it does not increase the susceptibility to lethal ventricular arrhythmia in rat.     

Disturbances in melatonin secretion and circadian sleep–wake regulation in Parkinson disease

ObjectiveUsing salivary dim light melatonin onset (DLMO) and actigraphy, our study sought to determine if Parkinson disease (PD) patients demonstrate circadian disturbance compared to healthy controls. Additionally, our study investigated if circadian disturbances represent a disease-related process or may be attributed to dopaminergic therapy.MethodsTwenty-nine patients with PD were divided into unmedicated and medicated groups and were compared to 27 healthy controls. All participants underwent neurologic assessment and 14 days of actigraphy to establish habitual sleep-onset time (HSO). DLMO time and area under the melatonin curve (AUC) were calculated from salivary melatonin sampling. The phase angle of entrainment was calculated by subtracting DLMO from HSO. Overnight polysomnography (PSG) was performed to determine sleep architecture.ResultsDLMO and HSO were not different across the groups. However, the phase angle of entrainment was more than twice as long in the medicated PD group compared to the unmedicated PD group (U = 35.5; P = .002) and was more than 50% longer than controls (U = 130.0; P = .021). The medicated PD group showed more than double the melatonin AUC compared to the unmedicated group (U = 31; P = 0.001) and controls (U = 87; P = .001). There was no difference in these measures comparing unmedicated PD and controls.ConclusionsIn PD dopaminergic treatment profoundly increases the secretion of melatonin. Our study reported no difference in circadian phase and HSO between groups. However, PD patients treated with dopaminergic therapy unexpectedly showed a delayed sleep onset relative to DLMO, suggesting dopaminergic therapy in PD results in an uncoupling of circadian and sleep regulation.