Factors Associated with Cheyne-Stokes Respiration in Acute Ischemic Stroke

Background and Purpose

Cheyne-Stokes respiration (CSR) is frequently observed in patients with acute stroke. There have been conflicting opinions about the associations of CSR with the location and size of the lesion. We aimed to better define the clinical relevance and pathogenesis of CSR in acute stroke.

Methods

We investigated patients who had been admitted with acute ischemic stroke and received an overnight sleep apnea test. We collected data on demographics, risk factors, etiologic subtypes, initial vital signs, clinical course of the stroke, and parameters associated with respiratory events during the sleep apnea test. We performed a multivariate logistic regression analysis to determine the factors associated with CSR.

Results

Among 182 patients, 35 patients showed CSR in sleep apnea testing. Large-artery atherosclerosis or cardioembolism, bilateral hemispheric involvement, atrial fibrillation, low left-ventricle ejection fraction (LVEF), and left atrium (LA) enlargement were all associated with the presence of CSR. Multivariate analysis revealed that the previous modified Rankin Scale (mRS) score, bilateral hemispheric involvement, low LVEF, and LA enlargement were significantly associated with CSR. Subgroup analysis with large-artery atherosclerosis without cardiac disease revealed that the previous mRS score is the only independent factor associated with CSR.

Conclusions

CSR frequently occurs in strokes involving large arteries or due to cardioembolism, regardless of the location and severity of the stroke. Predisposing conditions such as preexisting neurologic disability, low LVEF, and LA enlargement are associated with CSR in acute stroke.

Increased Risk of Ischemic Stroke during Sleep in Apneic Patients

Background and Purpose

The literature indicates that obstructive sleep apnea (OSA) increases the risk of ischemic stroke. However, the causal relationship between OSA and ischemic stroke is not well established. This study examined whether preexisting OSA symptoms affect the onset of acute ischemic stroke.

Methods

We investigated consecutive patients who were admitted with acute ischemic stroke, using a standardized protocol including the Berlin Questionnaire on symptoms of OSA prior to stroke. The collected stroke data included the time of the stroke onset, risk factors, and etiologic subtypes. The association between preceding OSA symptoms and wake-up stroke (WUS) was assessed using multivariate logistic regression analysis.

Results

We identified 260 subjects with acute ischemic strokes with a definite onset time, of which 25.8% were WUS. The presence of preexisting witnessed or self-recognized sleep apnea was the only risk factor for WUS (adjusted odds ratio=2.055, 95% confidence interval=1.035–4.083, p=0.040).

Conclusions

Preexisting symptoms suggestive of OSA were associated with the occurrence of WUS. This suggests that OSA contributes to ischemic stroke not only as a predisposing risk factor but also as a triggering factor. Treating OSA might therefore be beneficial in preventing stroke, particularly that occurring during sleep.

Obstructive sleep apnea and risk for late-life depression

BACKGROUND

Obstructive sleep apnea (OSA) is a sleep-related breathing disorder characterized by repetitive pharyngeal collapse. Because of the association between OSA, ischemia, and late-life depression, we hypothesized that older patients with OSA would have a higher prevalence of depression relative to their younger counterparts.

METHODS

We retrospectively reviewed charts of patients evaluated at the Sleep Disorders Center (SDC) at University of Iowa Hospitals and Clinics. A total of 617 patients age≥18 seen at SDC for diagnostic and therapeutic sleep studies were identified. Patients with a chart diagnosis of depressive disorder or treatment with antidepressants were identified as having a depressive disorder. Patients with an Apnea/Hypopnea Index≥5 were identified as having OSA.

RESULTS

No evidence of an escalating prevalence of depression with age was found in patients with OSA relative to those without the disorder. Prevalence of depression was similar in the OSA and the nonapnea groups (40.9% vs 40.3%, respectively; χ2=0.02; df=1; P=.89). Individuals with OSA had a significantly higher body mass index and greater number of chart diagnoses of hypertension, diabetes mellitus, and coronary artery disease compared with the nonapnea group.

CONCLUSIONS

The prevalence of depression among individuals with OSA does not appear to be moderated by age. Similarly high rates of depression were observed across the population of individuals referred for sleep studies, whether or not they were diagnosed with OSA.

Management of sleep disorders in stroke

OPINION STATEMENT

Scientific studies have proven a very strong association between stroke and obstructive sleep apnea (OSA). The prevalence of OSA is very high in patients with acute stroke, and untreated OSA is a stroke risk factor. In the stroke patient population, symptoms of OSA may atypically appear as isolated insomnia, hypersomnia, a dysfunction of circadian rhythm, a parasomnia, or a sleep-related movement disorder. Thus, we believe that in patients with acute stroke, OSA should be addressed first, using full in-laboratory, attended polysomnography (PSG), before other specific sleep disorders are aggressively addressed with specific therapeutic interventions. When OSA is diagnosed, supportive techniques including the application of continuous positive airway pressure (CPAP) therapy, positional therapies, or both should be considered first-line treatments. If OSA is ruled out by PSG, the therapeutic emphasis for sleep-related complaints is routinely based on instituting good sleep hygiene practices and using cognitive behavioral techniques (cognitive therapies, sleep restriction, stimulus control, and progressive relaxation therapies) because patients with stroke may be prone to the adverse effects of many of the medications that are otherwise routinely prescribed for a variety of specific sleep disorders.

Obstructive sleep apnea and stroke

Obstructive sleep apnea (OSA) and stroke are frequent, multifactorial entities that share risk factors, and for which case-control and cross-sectional studies have shown a strong association. Stroke of respiratory centers can lead to apnea. Snoring preceding stroke, documentation of apneas immediately prior to transient ischemic attacks, the results of autonomic studies, and the circadian pattern of stroke, suggest that untreated OSA can contribute to stroke. Although cohort studies indicate that OSA is a stroke risk factor, controversy surrounds the cost-effectiveness of the screening for and treatment of OSA once stroke has occurred.