Alternating leg muscle activation during sleep and arousals: A new sleep-related motor phenomenon?

We describe a quickly alternating pattern of anterior tibialis activation, recorded during nocturnal polysomnography in 16 patients. Polysomnography, usually for sleep-disordered breathing, included surface electromyograms over the anterior tibialis of each leg. Cases were identified from approximately 1,500 studies reviewed in the course of standard clinical care. Patients were 12 men and 4 women (mean age, 41 ± 15 years; range, 12–70 years). Brief activation of the anterior tibialis in one leg alternated with similar activation in the other leg. Activations occurred at a frequency of approximately 1 to 2 Hz, each lasted between 0.1 and 0.5 seconds, and sequences of alternating activations usually lasted between several and 20 seconds. The phenomenon occurred in all sleep stages but particularly during arousals. Ten of the 16 patients had periodic leg movements during sleep at a rate ≥ 5.0 per hour, and 12 of the 16 patients were taking antidepressant medication. Alternating leg muscle activation (ALMA) during sleep, at this relatively high frequency, may be a newly described phenomenon. We speculate that ALMA could represent transient facilitation of a spinal central pattern generator for locomotion, perhaps due to serotonergic effects of antidepressant medication. © 2003 Movement Disorder SocietyPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34960/1/10397_ftp.pd

Sleep Disorders and Medical Conditions in Women

Abstract Sleep disorders affect women differently than they affect men and may have different manifestations and prevalences. With regard to obstructive sleep apnea (OSA), variations in symptoms may cause misdiagnoses and delay of appropriate treatment. The prevalence of OSA appears to increase markedly after the time of menopause. Although OSA as defined by the numbers of apneas/hypopneas may be less severe in women, its consequences are similar and perhaps worse. Therapeutic issues related to gender should be factored into the management of OSA. The prevalence of insomnia is significantly greater in women than in men throughout most of the life span. The ratio of insomnia in women to men is approximately 1.4:1.0, but the difference is minimal before puberty and increases steadily with age. Although much of the higher prevalence of insomnia in women may be attributable to the hormonal or psychological changes associated with major life transitions, some of the gender differences may result from the higher prevalence of depression and pain in women. Insomnia's negative impact on quality of life is important to address in women, given the high relative prevalence of insomnia as well as the comorbid disorders in this population. Gender differences in etiology and symptom manifestation in narcolepsy remain understudied in humans. There is little available scientific information to evaluate the clinical significance and specific consequences of the diagnosis of narcolepsy in women. Restless legs syndrome (RLS) is characterized by an urge to move the legs or other limbs during periods of rest or inactivity and may affect as much as 10% of the population. This condition is more likely to afflict women than men, and its risk is increased by pregnancy. Although RLS is associated with impaired quality of life, highly effective treatment is available.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63103/1/jwh.2007.0561.pd

Perception of Sleep in Recovering Alcohol-Dependent Patients With Insomnia: Relationship With Future Drinking

Subjective and objective measures of poor sleep in alcoholic insomniacs predict relapse to drinking. Nonalcoholic insomniacs underestimate their total sleep time (TST) and overestimate their sleep onset latency (SOL) and wake time after sleep onset (WASO) compared with polysomnography (PSG). This study evaluated 3 hypotheses: (1) subjective SOL would predict frequency of future drinking; (2) participants would overestimate SOL and WASO and underestimate TST; and (3) higher amounts of over- and underestimates of sleep at baseline would predict worse drinking outcomes prospectively. Methods : Participants ( N =18), mean age 44.6 years (±13.2), underwent an adaptation night and then 2 nights of PSG 3 weeks apart. They also provided morning estimates of SOL, WASO, TST, and sleep efficiency (SE). Following the baseline PSG, participants were followed over 12 weeks. A 2-way ANOVA (night × method of measuring sleep) compared results and regression analyses predicted drinking. Drinking outcomes were defined as number of days drinking (DD) and number of heavy-drinking days (HDD) during 2 consecutive 6-week follow-up periods. Results : Most participants (72%) overestimated SOL by a mean of 21.3 (±36) minutes compared with PSG [ F (1, 14)=7.1, p <0.03]. Unexpectedly, 89% underestimated WASO by a mean difference of 48.7 (±49) minutes [ F (1, 14)=15.6, p <0.01]. Drinking during the first 6-week study period was predicted by both subjective estimates of WASO and their accuracy, whereas drinking during the second 6-week period was predicted by both subjective estimations of sleep and rapid eye movement sleep latency. Conclusion : Greater subjective accuracy of wakefulness at night provided by the patient predicted drinking during the study. Unlike nonalcoholic insomniacs, this alcoholic sample significantly underestimated WASO compared with PSG values. The predictive ability of sleep parameters depended on the selected measure of drinking outcomes and when outcomes were measured. Subjective sleep measures were better predictors of future drinking than corresponding PSG measures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65202/1/j.1530-0277.2006.00245.x.pd

Autonomic dysfunction in obstructive sleep apnea is associated with impaired glucose regulation

Autonomic dysfunction has been theorized to be responsible for the increased risk of cardiovascular disease in obstructive sleep apnea (OSA). Previous studies did not control for the presence of impaired glucose regulation (IGR, comprising impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and diabetes) which is also associated with abnormalities in autonomic function. Thirty-two patients were recruited for the study. Patients underwent autonomic testing consisting of heart rate response to deep breathing, valsalva maneuver, tilt-up, and quantitative sudomotor axon reflex testing. Polysomnography (PSG) and a 2-h oral glucose tolerance test were performed. Results were analyzed with logistic regression, with age, race, body mass index (BMI), and gender as covariates. Nineteen of 24 patients with OSA had abnormal glucose (79%, p = 0.04) compared to two of nine patients without OSA. The correlation between IGR, OSA and total autonomic dysfunction was similar ( p = .10 for IGR, p = 0.06 for OSA). However, cardiac autonomic function was more strongly associated with IGR than OSA ( p = .10 vs. 0.50). Age was a significant confounder, as glucose correlated with adrenergic autonomic dysfunction significantly when age was removed from the model ( p = 0.006). The presence of IGR may be a confounding factor in studies of autonomic function in OSA. Larger studies are needed to delineate whether OSA is directly associated with autonomic dysfunction or whether the previously described association between dysautonomia and OSA may have been due to glucose dysregulation

EMG Variance During Polysomnography As An Assessment For REM Sleep Behavior Disorder

Study Objectives: In a previous study, we validated a polysomnographic assessment for REM sleep behavior disorder (RBD). The method proved to be reliable but required slow, labor-intensive visual scoring of surface electromyogram (EMG) activity. We therefore developed a computerized metric to assess EMG variance and compared the results to those previously published for visual scoring, bed partner-rated RBD symptom scores, and clinical assessments by sleep medicine specialists. Design: Retrospective validation of new computer algorithm Setting: Sleep research laboratory Participants: Twenty-three subjects: 17 with neurodegenerative disorders (9 with probable or possible RBD), and 6 controls. Interventions: N/A Methods: We visually scored 2 consecutive nocturnal polysomnograms for each subject. A computer algorithm calculated the variance of the chin EMG during all 3-second mini-epochs, and compared variances during REM sleep to a threshold defined by variances during quiet NREM sleep. The percentage of all REM mini-epochs with variance above this threshold created a metric, which we refer to as the supra-threshold REM EMG activity metric (STREAM) for each subject. Results: The STREAM correlated highly with the visually-derived score for RBD severity (Spearman rho = 0.87, P \u3c 0.0001). A clinical impression of probable or possible RBD was associated to a similar extent with both STREAM (Wilcoxon rank sum test, P = 0.009) and the visually-derived score (P = 0.018). An optimal STREAM cutoff identified probable or possible RBD with 100% sensitivity and 71% specificity. The RBD symptom score correlated with both STREAM (rho = 0.42, P = 0.046) and the visual score (rho = 0.42, P = 0.048). Conclusions: These results suggest that a new, automated assessment for RBD may provide as much utility as a more time-consuming manual approach

Asthma Control and Its Relationship with Obstructive Sleep Apnea (OSA) in Older Adults

Background/Objectives. Asthma in older individuals is poorly understood. We aimed to characterize the older asthma phenotype and test its association with obstructive sleep apnea (OSA). Design. Cross-sectional. Setting. Pulmonary and Asthma/Allergy clinics. Participants. 659 asthma subjects aged 18–59 years (younger) and 154 aged 60–75 (older). Measurements. Sleep Apnea scale of Sleep Disorders Questionnaire (SA-SDQ), asthma severity step (1–4, severe if step 3 or 4), established OSA diagnosis, continuous positive airway pressure (CPAP) use, and comorbidities. Results. Older versus younger had worse control, as assessed by asthma step, lung function, and inhaled corticosteroid use. Among older subjects, after controlling for known asthma aggravators, OSA diagnosis was the only factor robustly associated with severe asthma: on average, OSA was associated with nearly 7 times greater likelihood of severe asthma in an older individual (OR=6.67). This relationship was of greater magnitude than in younger subjects (OR=2.16). CPAP use attenuated the likelihood of severe asthma in older subjects by 91% (P=0.005), much more than in the younger asthmatics. Conclusion. Diagnosed OSA increases the risk for worse asthma control in older patients, while CPAP therapy may have greater impact on asthma outcomes. Unrecognized OSA may be a reason for poor asthma control, particularly among older patients