Sleep, Stroke and Poststroke

Association of Excessive Daytime Sleepiness with Cerebral Small Vessel Disease in Community-Dwelling Older Adults

PURPOSE

Excessive daytime sleepiness (EDS) and cerebral small vessel disease (CSVD) are common problems among older adults; however, their association is not clear. The present study aimed to investigate the frequency of EDS in CSVD patients and the relationship between EDS and neuroimaging markers of CSVD.

PATIENTS AND METHODS

We conducted a cross-sectional study among 1076 community-dwelling older adults aged 55-85 years. EDS was measured using the Epworth Sleepiness Scale (ESS), and EDS was defined as an ESS score greater than 10. Binary logistic regression was performed to assess the association between EDS and neuroimaging markers of CSVD.

RESULTS

Of the 1076 participants (mean age: 65.58 ± 6.46 years, 60.5% female), the prevalence of EDS was 10.0%. EDS was more frequent in participants with CSVD than in the total sample (20.0% vs 10.0%, p <0.001). In fully adjusted models, EDS was significantly correlated with CSVD burden (OR = 1.39, 95% CI 1.16 to 1.68, p <0.001), the severity of white matter hyperintensities (WMH) (OR = 1.33, 95% CI 1.14 to 1.54, p <0.001), and presence of lacunes (OR = 2.47, 95% CI 1.53 to 4.00, p <0.001) but not with the presence of cerebral microbleeds (CMBs) (OR=1.54, 95% CI 0.92 to 2.56, p = 0.099) or severity of enlarged perivascular spaces (EPVS) in basal ganglia (OR = 1.16, 95% CI 0.70 to 1.92, p = 0.564).

CONCLUSION

We found a high frequency of EDS symptoms in CSVD individuals. Further, EDS was significantly associated with WMH, lacunes, and CSVD burden. Our findings further suggest patients with CSVD may exhibit abnormal sleep-wake patterns.

Periodic Limb Movements Syndrome in Patients With Cerebral Small Vessel Disease: Protocol for a Prospective Observational Study

Background: Cerebrovascular diseases are the leading cause of cognitive decline and dementia. Therefore, the investigation of the potential ways to slow down the disease progression is an important research field. Periodic limb movements in sleep (PLMS) are known to be associated with transient changes in heart rate and blood pressure. These changes might influence the course of cerebral small vessel disease (cSVD). Nevertheless, the clinical significance of PLMS, particularly its influence on cardiovascular diseases course, is still controversial and underinvestigated.

Methods/design: Patients from 60 to 75 years old diagnosed with cSVD will undergo nocturnal polysomnography. Subjects with apnea/hypopnea index under 5 will be enrolled. Sleep quality and daytime functioning will be assessed at baseline with self-reported questionnaires. Brain MRI and cognitive assessment will be performed at baseline and in the 2-year follow-up. Progression of cSVD markers and cognitive dysfunction will be compared between patients with PLMS index (PLMI) equal to or more than 15 movements per hour of sleep and controls (PLMI <15/h).

Discussion: The negative role of PLMS in cSVD progression and related cognitive decline is expected. We suppose that patients with PLMS tend to worsen in cognitive performance more rapidly than age-, gender-, and comorbidity-matched controls. We also expect them to have more rapid white matter hyperintensities and other cSVD marker progression. The limitations of the study protocol are the short follow-up period, the absence of a treatment group, and inability to make a conclusion about causality.

[Periodic limb movements in sleep and clinicomorphological features of cerebral small vessel disease]

OBJECTIVE

To search for the association between white matter deterioration extend as well as related cognitive dysfunction and periodic limb movements in sleep (PLMS) in patients with cerebral small vessel disease (cSVD).

MATERIAL AND METHODS

Thirty-four subjects with cSVD were enrolled (12 men, 22 women, average age 66.9 y.o.). The study protocol includes nocturnal actigraphy, cardiorespiratory monitoring, cognitive assessment and brain MRI. Two groups were formed depending on PLMS index. The patients of the main group had PLMS index equal or more than 15 movements per hour, and the controls had PLMS index less than 15.

RESULTS AND CONCLUSION

The significant differences between groups are shown in the executive functioning (p=0.0025 for the Frontal Assessment battery, p=0.036 for TMT-B, p=0.009 for TMT-A) and in the volume of juxtacortical white matter hyperintensities (WMH) (p=0.009). The positive correlation of PLMS features with total and periventricular volume of WMH and the negative correlation of PLMS features with cognitive performance are found as well.

Relationship between obstructive sleep apnea and neuroimaging signatures of cerebral small vessel disease in community-dwelling older adults. The Atahualpa Project

BACKGROUND/OBJECTIVES

Evidence of a relationship between obstructive sleep apnea (OSA) and neuroimaging signatures of cerebral small vessel disease (SVD) is limited. The present study aimed to evaluate this association in older adults living in rural Ecuador, where small vessel disease is a major pathogenetic mechanism underlying stroke.

METHODS

A representative random sample of Atahualpa residents aged ≥60 years enrolled in the Atahualpa Project neuroimaging substudy underwent a single-night diagnostic polysomnography. We evaluated whether OSA associates with severity of white matter hyperintensities (WMH), silent lacunar infarctions and deep cerebral microbleeds, using multivariate models adjusted for relevant confounders.

RESULTS

Of 351 candidates, 104 (30%) were randomly selected. Of these, 97 individuals (mean age 72.3 ± 7 years, 65% women) had adequate recordings and were included. Mean apnea/hypopnea index was 13.8 ± 14.1 episodes per hour; 27 persons (28%) had ≥15 episodes per hour and were considered to have moderate-to-severe OSA. Moderate-to-severe WMH were noticed in 25 individuals (25.8%), silent lacunar infarctions in 22 (22.7%) and deep cerebral microbleeds in 12 (12.4%). In multivariate models, OSA was associated with moderate-to-severe WMH (OR: 3.94; 95% C.I.: 1.09-14.97; p = 0.037), but not with silent lacunar infarctions (p = 0.195) or deep cerebral microbleeds (p = 0.405). A linear regression model confirmed the independent association between the apnea/hypopnea index and moderate-to-severe WMH (β: -7.14; 95% C.I.: -13.6 to -0.69; p = 0.031).

CONCLUSIONS

Individuals with moderate-to-severe OSA are almost four times more likely to have diffuse subcortical damage of vascular origin than those with none-to-mild OSA, independently of demographics and cardiovascular risk factors.

Sleep apnoea and stroke

Sleep disorders have been known to physicians for a long time. In his famous aphorisms, Hippocrates said “Sleep or watchfulness exceeding that which is customary, augurs unfavorably”. Modern medicine has been able to disentangle some of the phenomena that disturb sleep. Among the most notable offenders is sleep apnoea that has gained prominence in the past few decades. It is being proposed as one of the potentially modifiable risk factors for vascular diseases including stroke. The pathological mechanisms linking sleep apnoea to vascular risk factors include hypoxia, cardiac arrhythmias, dysautonomia, impaired glucose tolerance, hypertension, dyslipidaemia and inflammation. In this article, we review literature linking sleep apnoea and stroke, including sleep apnoea as a risk factor for primary prevention with the potential to improve outcome after acute stroke and as a secondary risk factor, amenable to modification and hence vascular risk reduction.

Consequences of Circadian Disruption on Neurologic Health

Circadian rhythms have a major role in physiology and behavior. Circadian disruption has negative consequences for physiologic homeostasis at molecular, cellular, organ-system, and whole-organism levels. The onset of many cerebrovascular insults shows circadian temporal trends. Impaired sleep-wake cycle, the most robust output rhythms of the circadian system, is significantly affected by neurodegenerative disorders, may precede them by decades, and may also affect their progression. Emerging evidence suggests that circadian disruption may be a risk factor for these neurologic disorders. This article discusses the implications of circadian rhythms in brain disorders, with an emphasis on cerebrovascular and neurodegenerative disorders.