Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0037315 (sleep apnea)
 8,000 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Stroke and sleep-disordered breathing (SDB) are both common and are associated with significant morbidity and mortality. Several recent large epidemiologic studies have shown a strong association between these two disorders independent of known risk factors for stroke. This review will outline the scientific basis for this relationship and suggest SDB as a modifiable risk factor for stroke. Several studies have shown a characteristic circadian rhythmicity in stroke. The authors discussed the influence of normal sleep states as well as the effect of SDB on cerebral hemodynamics. The hemodynamic, metabolic, and hematologic changes during SDB in the form of decreased cerebral perfusion and increased coagulability are the possible pathogenetic mechanisms for stroke. There are accumulating lines of evidence that SDB may indeed cause diurnal hypertension. However, the increased risk of stroke in patients with SDB appears to be independent of coexisting hypertension, but the presence of hypertension would greatly increase the risk even further. Furthermore, several studies have documented high prevalence of sleep apnea in patients with transient ischemic attacks and stroke. SDB appears to contribute as a risk factor for stroke through hemodynamic and hematologic changes. Because of high prevalence of SDB in this population, patients with transient ischemic attacks and stroke should be screened for these disorders.
 ...
PMID:Sleep-disordered breathing: implications in cerebrovascular disease. 1531 84

Stroke is the 3rd leading cause of death and a major cause of serious long-term disability in the United States. There are several well established and modifiable risk factors for the development of stroke. These include arterial hypertension, cardiac disease, dyslipidemia, diabetes mellitus and smoking among others. Sleep apnea has been found at alarmingly high rates (>50%) in patients with acute stroke as well as after neurologic recovery leading some to speculate that sleep apnea had been present prior to stroke. Sleep apnea is highly prevalent in the general population with a frequency of 2% to 4%. Sleep apnea is associated with high incidence of obesity, coronary artery disease and hypertension. There are several hematologic and hemodynamic changes in sleep apnea that can play significant roles in the pathogenesis of stroke. In this review, the author provides a critical analysis of the association between sleep apnea and stroke. There is convincing evidence to believe that sleep apnea is a modifiable risk factor for stroke, however, prospective studies are needed to establish the cause-and-effect relationship. Stroke and sleep-related breathing disorders are both common and are associated with significant morbidity and mortality. Several recent large epidemiological studies have shown a strong association between these 2 disorders independent of known risk factors for stroke. Understanding the link between obstructive sleep apnea and stroke may provide a novel preventative and therapeutic approach in the management of stroke.
 ...
PMID:Is sleep apnea a risk factor for stroke? A critical analysis. 1533 43

Previous studies have shown a peak occurrence of ischemic stroke in the morning but no consistent finding has been attributed to this. Focused on lacunar strokes we performed a prospective study with a detailed diagnostic protocol including parameters of recent infection, indicators of sleep apnea and cerebral vasoreactivity (CVR), aimed at defining differences in risk profiles between diurnal and nocturnal strokes. Consecutively we included 33 nocturnal and 54 diurnal strokes. Baseline characteristics, known risk factors, stroke severity and topology were not different between groups. The mean low-density lipoprotein (LDL) cholesterol level was significantly higher amongst patients with nocturnal strokes (133.3 +/- 35.2 mg/dl vs. 115.5 +/- 39.8 mg/dl; P = 0.04), as well as the proportion of patients with any dyslipidemia (94% vs. 77.8%; P = 0.047). Twenty-four-hour blood pressure recordings showed a reduced nocturnal decrease of blood pressure in subjects with strokes that occurred between 10 pm and 6 am in comparison with those whose strokes occurred between 6 am and 2 pm (5.0 +/- 7.3% vs. 11.0 +/- 6.7%; P = 0.049). No significant differences were found for parameters of recent infection (including seroreactivity against Chlamydia pneumoniae and cytomegalovirus), CVR, indicators of sleep apnea and the degree of white matter disease assessed by magnetic resonance tomography. Dyslipidemia, especially elevated LDL cholesterol is more prevalent in nocturnal lacunar strokes especially when combined with a reduced nocturnal dipping of blood pressure. This risk factor profile can be regarded as an additional target for stroke prevention.
 ...
PMID:Dyslipidemia, elevated LDL cholesterol and reduced nocturnal blood pressure dipping denote lacunar strokes occurring during nighttime. 1552 95

Significant progress in the field of VaD resulted from publication of the NINIDS-AIREN Diagnostic Criteria for VaD (G.C. Roman, T.K. Tatemichi, T. Erkinjuntti, et al., Vascular dementia (VaD): diagnostic criteria for research studies. Report of the NINDS-AIREN International Workshop. Neurology 43 (1993) 250-260). Epidemiological studies confirmed the importance of VaD as the second most common cause of dementia in the elderly, representing 15-20% of all cases of dementia. In Europe and North America, Alzheimer's disease (AD) predominates over VaD in a 2:1 ratio; in contrast, in Japan and China VaD accounts for almost 50% of all dementias. Case-control studies have identified risk factors for VaD including ageing, hypertension, diabetes mellitus, hyperlipidemia, recurrent stroke, cardiac disease, smoking, sleep apnea, and more recently, hyperhomocysteinemia, among others. Hypertension treatment may prevent VaD and AD. This finding has enormous importance from the Public Health viewpoint to decrease the future number of patients with dementia in the elderly. Along with advances in the field of VaD came a number of controversies and damaging misconceptions and myths. Myth no. 1--Vascular dementia is a non-entity: The false idea that VaD does not exist is particularly destructive because it creates the perspective that VaD is unworthy of study or research. A condition that either does not exist or represents only a minute proportion of all cases of dementia in the elderly, lacks public health relevance and becomes a low priority for research by funding agencies and industry. In fact, vascular brain lesions are the commonest and most important component of dementia in the elderly. Myth no. 2--Vascular dementia is so difficult to diagnose that only experts can recognize and identify it accurately: VaD does exist and the diagnosis of post-stroke VaD, in particular is straightforward. Most cases fulfill NINDS-AIREN criteria for probable VaD; i.e., (1) there is acute onset of dementia demonstrated by impairment of memory and two other cognitive domains, such as orientation, praxis or executive dysfunction; (2) relevant cerebrovascular lesions are demonstrated by neuroimaging; and (3) a temporal relation between stroke and cognitive loss is evident. In the donepezil trials on VaD, post-stroke dementia represented about 75% of the >1,200 patients enrolled. Myth no. 3--Improvement in clinical trials of cholinergics in VaD is due to underlying AD, not to the vascular lesions. Experimental, clinical and pathological evidence has demonstrated cholinesterase deficits in VaD (independently of any concomitant AD pathology), including low acetylcholine in cerebrospinal fluid, and reduced choline acetyltransferase (ChAT) in the brain.
 ...
PMID:Facts, myths, and controversies in vascular dementia. 1553 19

Disruption of circadian rhythm of blood pressure (BP) is associated with advanced target organ damage and poor cardiovascular prognosis. We studied silent cerebrovascular disease and stroke events in older Japanese patients with different nocturnal BP dipping. There was a J-shaped relationship of nocturnal dipping status with silent cerebral infarcts detected by brain MRI at baseline, and with stroke incidence during the follow-up period. The extreme-dippers (with marked nocturnal BP dipping) and risers (with higher nocturnal BP than awake BP) had a higher prevalence of silent cerebral infarcts and poorer stroke prognosis than those with appropriate nocturnal BP dipping (dippers). Extreme-dippers tended to have predominant systolic hypertension and increased BP variability. Several factors are affecting the diurnal BP variation pattern. The non-dipping pattern is associated with autonomic nervous dysfunction and poor sleep quality due to nocturnal behavior and sleep apnea. Extreme-dippers might have increased arterial stiffness with reduced circulating blood volume in addition to an excessive morning surge due to alpha-adrenergic hyperactivity. Morning BP surge, which is partly associated with nocturnal BP dipping status, was a predictor of stroke event independently for ambulatory BP level and silent cerebral infarcts. Antihypertensive medication that normalize the disrupted circadian BP variation might improve cardiovascular prognosis in high-risk hypertensive patients.
 ...
PMID:[Blood pressure variation and cardiovascular risk in hypertension]. 1555 1

In recent years there has been increasing interest in the relationship between obstructive sleep apnoea and stroke. It is clear that many patients who have had a stroke have marked obstructive sleep apnoea. This is seen during recovery but also during the acute phase when transient hypoxaemia and the blood pressure swings associated with upper airway obstruction, may worsen the ischaemic penumbra of the area of the brain which is compromised, leading to a worse outcome. There is some evidence to support this hypothesis. This article explores these issues.
 ...
PMID:Sleep disordered breathing following stroke. 1567 9

Sleep apnea is increasingly associated with risk of cardiovascular disease, including arrhythmia, heart failure, stroke, ischemic heart disease, and hypertension. Diagnosis and treatment of sleep apnea and the implications for cardiovascular disease are discussed.
 ...
PMID:Sleep-disordered breathing: implications for the pathophysiology and management of cardiovascular disease. 1579 21

Sleep apnea syndrome (SAS) is a prominent clinical feature in acute stroke patients. Diagnosis is usually established by polysomnography or cardio-respiratory polygraphy (CRP). Both diagnostic procedures produce high costs, are dependent on the access to a specialized sleep laboratory, and are poorly tolerated by patients with acute stroke. In this study we therefore investigated whether capnography may work as a simple screening tool in this context. In addition to conventional CRP, 27 patients with acute stroke were studied with capnography provided by our standard monitoring system. The trend graphs of the end-tidal CO(2) values (EtCO(2)) were used to determine the capnography-based estimate of the apnea-hypopnea index (AHI(CO2)). Index events were scored when the EtCO(2) value dropped for > 50% of the previous baseline value. We found that the AHI(CO2) correlated significantly with the apnea-hypopnea index measured with conventional CRP (AHI(CRP)) (r = 0.94; p < 0.001). An AHI(CO2) > 5 turned out to be highly predictive of an AHI(CRP) > 10. According to our findings, routinely acquired capnography may provide a reliable estimate of the AHI(CRP). The equipment needed for this screening procedure is provided by the monitoring systems of most intensive care units and stroke units where stroke patients are regularly treated during the first days of their illness. Therefore, early diagnosis of SAS in these patients is made substantially easier.
 ...
PMID:Capnography screening for sleep apnea in patients with acute stroke. 1582 65

The activation of adrenergic and renin-angiotensin-aldosterone (RAA) systems observed in patients with obstructive sleep apnoea syndrome (OSA) strongly affects functional status of the cardiovascular system. In this paper we discuss the link between obstructive sleep apnoea syndrome and common cardiovascular diseases such as systemic and pulmonary hypertension, ischaemic heart disease, stroke, arrhythmia and ventricular hypertrophy. We also present the importance of early pharmacologic treatment in preventing cardiac hypertrophy and ventricular dysfunction in patients with obstructive sleep apnoea syndrome.
 ...
PMID:[Cardiovascular abnormalities in patients with obstructive sleep apnoea syndrome]. 1599 58

Since sleep apnea (SA) and stroke have many shared risk factors an independent contribution of SA to the overall risk of stroke is not easily proven and has been questioned recently. To contribute to this controversy, we analysed the frequency of SA in groups of patients with first and recurring ischemic stroke. We prospectively studied 102 patients admitted to our stroke unit. The prevalence of vascular risk factors and a history of previous stroke were recorded. All patients received cardio-respiratory polygraphy during the first 72 hours after admission. CT and MRI scans were evaluated for the location of the acute stroke and the presence of older vascular lesions. Thirty-four women and 68 men with a mean age of 64.5 +/- 13.7 years were included in the study. Cerebral lesions attributable to a previous stroke were identified in 25 patients, of whom 19 reported to have suffered a stroke before. Patients with stroke recurrence had a higher mean apnea-hypopnea index (AHI) (26.6/h vs. 15.1/h, p<0.05) and more often presented with a sleep apnea syndrome (SA) defined by an AHI >or=10/h (80 vs. 52%, p < 0.05) than patients with first ever stroke. Logistic regression analysis including the variables "age", "gender", "cumulative risk factors", "AHI >or=10/h", and "diabetes" identified diabetes (Odd's ratio [OR]=4.5) and AHI >or=10/h (OR=3.5) as independent risk-factors for stroke recurrence. According to our results SA is an independent risk factor for stroke recurrence. We therefore advocate routine sleep-apnea screening in all patients having suffered an ischemic stroke.
 ...
PMID:Increased prevalence of sleep apnea in patients with recurring ischemic stroke compared with first stroke victims. 1602 59


<< Previous 1 2 3 4 5 6 7 8 9 10