Adherence to positive airway pressure therapy initiated in the early subacute phase of ischemic stroke: a PRESS study follow-up

BACKGROUND

Sleep-disordered breathing (SDB) is frequent in stroke patients and negatively affects stroke outcomes. Positive airway pressure (PAP) is the standard first-line treatment for patients with moderate-to-severe SDB. Despite a strong link between PAP adherence and therapeutic response, rates of post-stroke PAP adherence remain underexplored. Our study aimed to determine PAP adherence in patients undergoing comprehensive sleep apnea assessment and in-lab PAP titration in the early subacute phase of stroke.

METHODS

In-hospital screening pulse oximetry was performed in consecutive patients with imaging-confirmed acute ischemic stroke. Subjects with desaturation index ≥ 15.3/h were selected as PAP candidates, and polysomnography was recommended. In a sleep laboratory setting, subjects underwent a diagnostic night followed by a titration night, and PAP therapy was initiated in subjects with apnea-hypopnea index ≥ 15/h. Adherence to PAP therapy was assessed at a 6-month follow-up visit.

RESULTS

Of 225 consecutive patients with acute ischemic stroke, 116 were PAP candidates and 52 were able to undergo polysomnography. PAP therapy was initiated in 35 subjects. At a 6-month follow-up visit, out of 34 stroke survivors, PAP adherence (PAP use of > 4 h per night) was present in 47%. Except for the significantly lower minimal nocturnal O2 saturation determined from the polysomnography (74.6 ± 11.7% vs. 81.8 ± 5.2%, p = 0.025), no other significant difference in characteristics of the groups with PAP adherence and PAP non-adherence was found.

CONCLUSIONS

Less than half of the stroke subjects remained adherent to PAP therapy at 6 months post-PAP initiation. Special attention to support adaptation and adherence to PAP treatment is needed in this group of patients.

Association between cognitive impairment and the disability in people with multiple sclerosis

BACKGROUND

Cognitive impairment (CI) may be present in people with multiple sclerosis (PwMS) in different stages of the disease, as well as in PwMS with various degrees of disability. This study aimed to investigate cognitive decline over a period of 12 months and to examine an association between cognition and the disability in PwMS, also over a period of 12 months.

METHODS

The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) battery was used, containing the Symbol Digit Modalities Test (SDMT), the Categorical Verbal Learning Test (CVLT), and the Brief Visuospatial Memory Test-Revised (BVMT-R). The Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), and 9-Hole Peg Test (9-HPT) were used to assess the degree of disability. For the analysis of cognitive decline over the period of 12 months, Wilcoxon signed-rank test (paired sample t-test) was used. For the correlation between cognition and disability, Spearman's correlation test was used.

RESULTS

We observed statistically meaningful difference only in one measure of cognition (CVLT), not the other two (SDMT and BVMT-R). SDMT significantly correlated with methods assessing the degree of disability in both time points. In the second examination, we observed a correlation between BICAMS and 9-HPT. Similarly, SDMT and BVMT-R also correlated with EDSS.

CONCLUSION

To investigate the cognitive decline in PwMS, a longer period of time probably should have been chosen. EDSS is commonly used to monitor disease progression, but it does not include the evaluation of various parameters, such as cognition or upper limb function. Its use with the 9-HPT and cognitive tests may represent a more reliable and comprehensive assessment of a patient's clinical condition.

No Difference in Sleep Desaturations Severity between Patients with Wake-Up and Non-Wake-Up Stroke: A PRESS Study Results

BACKGROUND

Wake-up stroke (WUS) is a certain type of ischemic stroke in which a patient wakes up with a new neurological deficit due to cerebral ischemia. Sleep-disordered breathing is an independent risk factor for stroke, but the role of nocturnal oxygen desaturation in the pathophysiology of WUS is still insufficiently explored. According to several studies, patients with WUS have a significantly more severe sleep apnea syndrome and lower mean blood oxygen saturation. This study aimed to assess the severity of nocturnal desaturations in acute WUS and non-WUS patients using nocturnal pulse oximetry.

MATERIAL AND METHODS

The cohort of 225 consecutive patients with neuroimaging-verified acute cerebral ischemia was prospectively enrolled. For further analyses, 213 subjects with known WUS/non-WUS status were selected (111 males and 102 females, average age 70.4 ±12.9, median baseline NIHSS = 5, median baseline mRS = 3). Patients were divided into the WUS group (n = 45) and the non-WUS group (n = 168). Overnight pulse oximetry was performed within 7 days of the stroke onset and data of both of the studied groups were compared.

RESULTS

We found oxygen desaturation index (ODI) in the WUS group was 14.5 vs. 16.6 (p = 0.728) in the non-WUS group, basal O2 saturation was 92.2% vs. 92.5% (p = 0.475), average low O2 saturation was 90.3% vs. 89.6% (p = 0.375), minimal O2 saturation was 79.5% vs. 80.6% (p = 0.563), and time with O2 saturation <90% (T90) was 4.4% vs. 4.7% (p = 0.729).

CONCLUSIONS

In the studied sample, monitored respiratory parameters including ODI, basal O2 saturation, average low O2 saturation, minimal O2 saturation, and T90 did not significantly differ between groups of WUS and non-WUS patients.

Impairment of endothelial function in Parkinson's disease

OBJECTIVE

There are conflicting data regarding the relationship between Parkinson's disease (PD) and the atherosclerotic process. This study aimed to compare endothelial function in patients with PD and matched controls. In PD subjects, we searched for factors contributing to endothelial dysfunction as well. Traditional vascular risk factors, PD characteristics, and PD medication were considered.

RESULTS

We prospectively enrolled 41 patients with PD and 41 controls matched for age, sex, body mass index, and vascular risk factors. Endothelial function (EF) was assessed using peripheral arterial tonometry (EndoPAT 2000 device) and expressed as reperfusion hyperemia index (RHI). Clinical characteristics including PD medication were recorded. RHI was non-significantly lower in the PD group than in controls (1.8 ± 0.5 vs. 1.9 ± 0.5, p = 0.478). In PD patients, in linear regression analysis, smoking (beta = -0.453, p = 0.008) and use of dopamine agonists (beta = -0.365, p = 0.030) were significant contributors in a model predicting RHI. Despite non-significant differences in endothelial dysfunction between PD patients and controls, our results suggest an association between smoking, dopamine agonists, and impaired EF in PD patients. The small sample size, as well as the absence of an extended search for traditional and non-traditional vascular risk factors, are the most important factors limiting the interpretation of the current results.

Cognition in Patients with Sleep-Disordered Breathing: Can Obstructive and Central Apneic Pauses Play a Different Role in Cognitive Impairment?

BACKGROUND

There are increasing data linking sleep apnea with cognitive impairment. We aimed to clarify the relationship between sleep-disordered breathing (SDB) and cognition. Detailed attention was assigned to the potential role of central versus obstructive apneic pauses in cognitive impairment.

METHODS

Patients with suspected SDB were prospectively enrolled, and a complex sleep study was performed that included overnight polysomnography. A revised version of Addenbrooke's Cognitive Examination (ACE-R) was used to assess cognition, evaluating overall cognition and individual subdomains.

RESULTS

A total number of 101 participants were included in the study. In multivariate binary logistic regression analysis, obstructive apnea index ([OAI], 95% CI: 1.009-1.057, p = 0.008) was the only significant contributor to the model predicting attention deficit. The proportion of N1 stage of NREM sleep was the only significant contributor to the model predicting impaired verbal fluency (95% CI: 1.004-1.081, p = 0.029). No significant differences in sleep-related indices were observed in the remaining ACE-R subdomains.

CONCLUSION

Except for verbal fluency and attention, we failed to find any significant association of sleep-related indices with the impairment in different cognitive subdomains. Our data suggest that impairment observed in verbal fluency is associated with a higher proportion of shallow NREM sleep, and attention deficit is associated with higher OAI. Obstructive respiratory episodes seem to play a more important role in cognitive impairment when compared to central ones.

Autonomic Nervous System Function in Newly Diagnosed Multiple Sclerosis: Association With Lipid Levels and Insulin Resistance

Autonomic nervous system (ANS) disorders are common in multiple sclerosis (MS). Previous studies showed differences in insulin resistance (IR) and lipoprotein levels in MS subjects compared to controls. Lipolysis caused by increased sympathetic activity could be one of the possible linking mechanisms leading to dyslipidemia in MS. Our study aimed to evaluate ANS activity in the context of glucose and lipid metabolism in people with MS. We prospectively measured short-term heart rate variability (HRV), fasting lipoprotein concentrations, and calculated IR indices based on plasma glucose and insulin levels during oral glucose tolerance test (oGTT) in 32 patients with MS and 29 healthy controls matched for age, sex and body mass index in our study. There was no significant difference in HRV parameters and lipoprotein levels between MS and controls. A significant positive correlation was found between low/high-frequency power ratio (LF/HF) and triglycerides (r=0.413, p=0.021) in MS subjects but not in controls. A significantly lower whole-body insulin sensitivity index (ISIMat) was found in patients with MS compared to the control group (7.3±3.7 vs. 9.8±5.6, p=0.041). No significant correlations were found between LF/HF and IR parameters. In MS subjects, the positive correlation of LF/HF with triglycerides could reflect the effects of sympathetic activity on lipolysis. Positive correlations of sympathetic activity with increased lipoprotein levels could rather reflect processes associated with immune system activation/inflammation, than processes involved in glucose homeostasis maintenance.

Effects of Short- and Long-Term Aerobic-Strength Training and Determinants of Walking Speed in the Elderly

BACKGROUND/AIMS

Walking speed (WS) is an objective measure of physical capacity and a modifiable risk factor of morbidity and mortality in the elderly. In this study, we (i) determined effects of 3-month supervised aerobic-strength training on WS, muscle strength, and habitual physical activity; (ii) evaluated capacity of long-term (21 months) training to sustain higher WS; and (iii) identified determinants of WS in the elderly.

METHODS

Volunteers (F 48/M 14, 68.4 ± 7.1 years) completed either 3-month aerobic-strength (3 × 1 h/week, n = 48) or stretching (active control, n = 14) intervention (study A). Thirty-one individuals (F 24/M 7) from study A continued in supervised aerobic-strength training (2 × 1 h/week, 21 months) and 6 (F 5/M 1) became nonexercising controls.

RESULTS

Three-month aerobic-strength training increased preferred and maximal WS (10-m walk test, p < 0.01), muscle strength (p < 0.01) and torque (p < 0.01) at knee extension, and 24-h habitual physical activity (p < 0.001), while stretching increased only preferred WS (p < 0.03). Effect of training on maximal WS was most prominent in individuals with baseline WS between 1.85 and 2.30 m·s-1. Maximal WS measured before intervention correlated negatively with age (r = -0.339, p = 0.007), but this correlation was weakened by the intervention (r = -0.238, p = 0.06). WS progressively increased within the first 9 months of aerobic-strength training (p < 0.001) and remained elevated during 21-month intervention (p < 0.01). Cerebellar gray matter volume (MRI) was positively associated with maximal (r = 0.54; p < 0.0001) but not preferred WS and explained >26% of its variability, while age had only minor effect.

CONCLUSIONS

Supervised aerobic-strength training increased WS, strength, and dynamics of voluntary knee extension as well as habitual physical activity in older individuals. Favorable changes in WS were sustainable over the 21-month period by a lower dose of aerobic-strength training. Training effects on WS were not limited by age, and cerebellar cortex volume was the key determinant of WS.

Sleep apnea prediction in acute ischemic stroke (SLAPS score): a derivation study

BACKGROUND

Despite its high prevalence and negative impact, sleep-disordered breathing (SDB) remain commonly underdiagnosed and undertreated in stroke subjects. Multiple stroke comorbidities and risk factors, including obesity, hypertension, diabetes mellitus, ischemic heart disease, atrial fibrillation, and heart failure (H.F.) have been associated with SDB. This study aimed to examine associations of clinical and demographic characteristics with moderate-to-severe SDB (msSDB) in stroke patients and to develop a predictive score.

METHODS

Consecutive patients with ischemic stroke were enrolled in an open, prospective study. SDB was assessed using standard polysomnography. Clinical and demographic characteristics, as well as findings from echocardiography, entered the analysis. Multivariate logistic regression models were used to examine the associations with msSDB. Based on the results, an original score to predict msSDB was proposed and tested.

RESULTS

120 patients with acute ischemic stroke (mean age: 64.0 ± 12.2 years, median NIHSS: 4) were included. Body-mass index (BMI), wake-up stroke onset (WUS), and diastolic dysfunction were independently associated with msSDB. A score allocating 1 point for BMI≥25 kg/m² and <30 kg/m², 2 points for BMI≥30 kg/m², 1 point for WUS and 1 point for diastolic dysfunction resulted in an area under the curve of 0.81 (95% CI 0.71-0.90, p<0.001), sensitivity 82.9%, specificity 71.9% to identify stroke patients with msSDB.

CONCLUSIONS

BMI, WUS, and diastolic dysfunction were associated with msSDB. A simple score might help to identify acute stroke patients with msSDB, who are usual candidates for positive airway pressure therapy.

Excessive daytime sleepiness in sleep apnea: any role of testosterone or vitamin D?

Recent studies reported association of sleep-disordered breathing (SDB) with testosterone and vitamin D deficiency. Low testosterone and vitamin D levels have been linked to fatigue and excessive daytime sleepiness (EDS). However, the impact of testosterone and vitamin D deficiency on EDS in subjects with SDB remains unknown. The aim of this study was to explore the predictors of EDS in habitual snorers. Role of testosterone, and vitamin D was studied in detail. We also looked for associations between testosterone, vitamin D, and sleep-related indices. We prospectively enrolled 291 consecutive male patients with habitual snoring. Baseline clinical characteristics were recorded on admission. Standard overnight polysomnography was performed to detect SDB, and Epworth Sleepiness Scale (ESS) was used to assess EDS. Blood samples were obtained in a fasting condition in the morning after polysomnography to determine levels of testosterone and vitamin D. Respiratory disturbance index (RDI) (95 % CI: 1.004-1.024, p=0.005) and the use of antihistamines (95 % CI: 1.083-11.901, p=0.037) were the only independent variables significantly associated with EDS in binary logistic regression analysis. In linear multiple regression analysis, body mass index (BMI) (Beta=-0.282, p<0.001) and oxygen desaturation index (Beta=-0.150, p=0.043) were the only independent variables significantly associated with testosterone levels, and BMI (Beta=-0.142, p=0.016) was the only independent variable significantly associated with vitamin D. We failed to find any independent association of testosterone and vitamin D with subjectively rated EDS among habitual snorers. Our results suggest an independent association between the magnitude of nocturnal desaturation and testosterone levels.

Lipoprotein profiling in early multiple sclerosis patients: effect of chronic inflammation?

Background

Inflammatory cytokines contribute to proatherogenic changes in lipid metabolism by reduction of HDL-cholesterol (HDL-C) levels, impairment of its antiinflammatory and antioxidant functions. Therefore, the protective actions of HDL-C can be limited in chronic inflammatory diseases such as multiple sclerosis (MS). The aim of this study was to assess the association between lipoprotein subfractions and inflammatory status in early stages of multiple sclerosis.

Methods

Polyacrylamide gel electrophoresis Lipoprint© System was used for lipoprotein profile analysis in 19 newly diagnosed MS patients, and in matched 19 healthy controls. Serum levels of interleukin (IL) 1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 (p70), IL-13, IL-17, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor, interferon-γ and TNF-α were measured by multiplex bead assay.

Results

Concentrations of the measured cytokines and lipoprotein subclasses were comparable between MS patients and controls. Male, but not female MS patients had significantly higher total HDL-C and small HDL-C subfraction than healthy controls. Large HDL-C negatively correlated with all measured cytokines except IL-17 in MS but not in controls. Intermediate HDL-C subfractions correlated positively with all measured cytokines except G-CSF in MS females but not in MS males or controls.

Conclusion

Our results of higher HDL-C and mainly its small HDL-C subfraction suggest that male MS patients are at higher risk of atherosclerosis and the subtle dyslipidemia is present in early stages of the disease. The correlations between specific HDL-C subfractions and the inflammatory cytokines demonstrate mutual links between systemic inflammation and lipid metabolism in MS.

Trial registration

ClinicalTrials.gov, Identifier: NCT 03052595 Registered on Feb 14, 2017.

Obstructive sleep apnea and hypertension: the role of gut microbiome

Obstructive sleep apnea is common disorder affecting approximately one quarter of the common population. Prevalence is even higher in a population with increased vascular risk. Obstructive sleep apnea is a significant risk factor for hypertension, with approximately 50% of obstructive sleep apnea patients suffering hypertension. While the relationship between sleep apnea and hypertension has been firmly established, mechanisms linking these disorders are still poorly understood. Importance of sympathetic nervous system and renin-angiotensin-aldosterone system hyperactivity as well as endothelial dysfunction is suspected. There is increasing evidence supporting gut dysbiosis as one of the underlying mechanisms. Current article describes possible mechanisms linking obstructive sleep apnea with the development of hypertension. The role of gut microbiota in this process is discussed more closely.

Real-World Treatment Patterns of Disease Modifying Therapy (DMT) for Patients with Relapse-Remitting Multiple Sclerosis and Patient Satisfaction with Therapy: Results of the Non-Interventional SKARLET Study in Slovakia

BACKGROUND

During long-term multiple sclerosis therapy, patient satisfaction with received treatment has considerable impact on treatment outcomes. Here we report the results of a non-interventional real-world study that mapped the treatment patterns of disease-modifying therapy (DMT) and assessed treatment satisfaction with DMT.

PATIENTS AND METHODS

The SKARLET study was a non-interventional, cross-sectional study in Slovakia running from May 2016 to March 2017. Patients with relapsing-remitting multiple sclerosis on DMT for ≥3 months and ≤2 years (per local labelling) from 10 multiple sclerosis centers across Slovakia were included. The primary objective was to collect the Treatment Satisfaction Questionnaire for Medication version 9 (TSQM 9) score regarding perceived effectiveness, convenience and overall satisfaction with DMT.

RESULTS

The following TSQM 9 scores (mean; 95% confidence interval) were reported from 415 patients: convenience (75.05; 73.49-76.61), effectiveness (68.15; 66.56-69.75) and global satisfaction scale (66.94; 65.26-68.62). All three parameters of the TSQM 9 were analyzed by the route of DMT administration, with infusions best rated for effectiveness and global satisfaction in comparison to oral dosage and injections. For convenience, however, oral dosage forms were appraised highly (82.66; 80.59-84.73) followed by infusions (74.40; 70.12-78.69), while injections were rated as the worst (66.92; 64.81-69.04). The difference of TSQM 9 scores according to the route of DMT administration is statistically significant for convenience (p < 0.001) and global satisfaction (p = 0.004), but not for effectiveness (p = 0.185).

CONCLUSION

In the present study, it was confirmed that patients find oral DMTs as most convenient; however, the infusion form of treatment outweighs oral DMTs in global satisfaction and effectiveness. The differences of TSQM 9 scores among DMT dosage forms were significant for convenience and global satisfaction. In conclusion, the results of this detailed survey increase our understanding of RRMS patient population characteristics and patient satisfaction with DMT treatment.

Acute and regular exercise distinctly modulate serum, plasma and skeletal muscle BDNF in the elderly

Brain-derived neurotrophic factor (BDNF) participates in orchestrating the adaptive response to exercise. However, the importance of transient changes in circulating BDNF for eliciting whole-body and skeletal muscle exercise benefits in humans remains relatively unexplored. Here, we investigated effects of acute aerobic exercise and 3-month aerobic-strength training on serum, plasma and skeletal muscle BDNF in twenty-two sedentary older individuals (69.0 ± 8.0 yrs., 9 M/13F). BDNF response to acute exercise was additionally evaluated in young trained individuals (25.1 ± 2.1 yrs., 3 M/5F). Acute aerobic exercise transiently increased serum BDNF in sedentary (16%, p = .007) but not in trained elderly or young individuals. Resting serum or plasma BDNF was not regulated by exercise training in the elderly. However, subtle training-related changes of serum BDNF positively correlated with improvements in walking speed (R = 0.59, p = .005), muscle mass (R = 0.43, p = .04) and cognitive performance (R = 0.41, p = .05) and negatively with changes in body fat (R = -0.43, p = .04) and triglyceridemia (R = -0.53, p = .01). Individuals who increased muscle BDNF protein in response to 3-month training (responders) displayed stronger acute exercise-induced increase in serum BDNF than non-responders (p = .006). In addition, muscle BDNF protein content positively correlated with type II-to-type I muscle fiber ratio (R = 0.587, p = .008) and with the rate of post-exercise muscle ATP re-synthesis (R = 0.703, p = .005). Contrary to serum, acute aerobic exercise resulted in a decline of plasma BDNF 1 h post-exercise in both elderly-trained (-34%, p = .002) and young-trained individuals (-48%, p = .034). Acute circulating BDNF regulation by exercise was dependent on the level of physical fitness and correlated with training-induced improvements in metabolic and cognitive functions. Our observations provide an indirect evidence that distinct exercise-induced changes in serum and plasma BDNF as well as training-related increase in muscle BDNF protein, paralleled by improvements in muscle and whole-body clinical phenotypes, are involved in the coordinated adaptive response to exercise in humans.

Gender differences in LDL- and HDL-cholesterol subfractions in patients after the acute ischemic stroke and their association with oxidative stress markers

The aim of our study was to examine gender differences of LDL- and HDL-cholesterol subfractions in patients after the acute ischemic stroke with focus on small LDL and HDL subfractions, and their association with oxidative stress markers. In addition, we have monitored the 7-day effect of cholesterol-lowering drugs administered to patients after the acute ischemic stroke, on these subfractions. Eighty two stroke patients and 81 age matched controls were included in this study. Blood was collected from patients within 24 h after the stroke (group A) and re-examined at the 7-day follow-up (group B). We have found gender differences in LDL- and HDL-subfractions in stroke patients, lipid-lowering drugs administered to acute ischemic stroke patients significantly reduced all measured parameters of lipoprotein profile. In the group A LDL1 subfraction positively correlated with activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase) indicating a protective role of this subfraction. On the contrary, small HDL subfractions positively correlated with lipoperoxide levels and negatively with trolox equivalent antioxidant capacity in plasma suggesting a negative role of these subfractions. In this work we have confirmed the hypothesis of atherogenic properties of small HDL subfractions and anti-atherogenic properties of large LDL1-subfractions.

Management of multiple sclerosis patients in central European countries: current needs and potential solutions

Multiple sclerosis (MS) experts in Europe are facing rapidly rising demands of excellence due to the increasing complexity of MS therapy and management. A central European expert board of MS experts met to identify needs and obstacles with respect to raising quality of MS care in central and Eastern European countries. There are substantial variations across countries regarding delivery of care and its cost structure, as well as access to treatment. To date, Eastern European countries are often less able to afford reimbursement of immunomodulatory agents than Western countries. Overall, approximately 40% of working-age patients are not working due to MS. Costs rise steeply with increasing disability; indirect costs constitute the bulk of the financial burden in patients with severe MS. Magnetic resonance imaging (MRI) assessment is meanwhile obligatory as the diagnostic interface in the management of MS patients. Recommended measures directed at improving quality of care include the collection of patient data in registries, enhanced education of healthcare professionals, implementation of national strategies aiming at reducing regional variation, optimization of approval processes, and removal of administrative barriers. Local partnerships with authorities such as those that represent the interests of employees can contribute to leverage the importance of epidemiological data. The need for education extends to (neuro)radiologists who are responsible for reporting MRI findings in expert quality. Dissemination of the Magnetic Resonance Imaging in MS (MAGNIMS) protocol would be an important step in this context. Also, clinical freedom of choice is rated as essential. Physicians should have access to a range of treatment options due to the complexity of disease. Guidelines such as the upcoming EAN-ECTRIMS clinical practice guideline also aim at providing a basis for argumentation in negotiations with national health authorities.

Excessive Daytime Sleepiness in Acute Ischemic Stroke: Association With Restless Legs Syndrome, Diabetes Mellitus, Obesity, and Sleep-Disordered Breathing

STUDY OBJECTIVES

Sleep disorders are frequent in stroke patients. The prevalence of sleep-disordered breathing (SDB), excessive daytime sleepiness (EDS), and restless legs syndrome (RLS) among stroke survivors is up to 91%, 72%, and 15%, respectively. Although the relationship between EDS and SDB is well described, there are insufficient data regarding the association of EDS with RLS. The aim of this study was to explore the association between EDS, SDB, and RLS in acute ischemic stroke.

METHODS

We enrolled 152 patients with acute ischemic stroke. Epworth Sleepiness Scale (ESS) was used to assess EDS. SDB was assessed using standard overnight polysomnography. All patients filled in a questionnaire focused on RLS. Clinical characteristics and medication were recorded on admission.

RESULTS

EDS was present in 16 (10.5%), SDB in 90 (59.2%) and RLS in 23 patients (15.1%). EDS was significantly more frequent in patients with RLS in comparison with the patients without RLS (26.1% versus 7.8%, P = .008). ESS was significantly higher in the population with RLS compared to the population without RLS (7 [0-14] versus 3 [0-12], P = .032). We failed to find any significant difference in the frequency of EDS and values of ESS in the population with SDB compared to the population without SDB. Presence of RLS (beta = 0.209; P = .009), diabetes mellitus (beta = 0.193; P = .023), and body mass index (beta = 0.171; P = .042) were the only independent variables significantly associated with ESS in multiple linear regression analysis.

CONCLUSIONS

Our results suggest a significant association of ESS with RLS, diabetes mellitus, and obesity in patients with acute ischemic stroke.

Obstructive sleep apnea and dyslipidemia

Obstructive sleep apnea is a sleep disorder characterized by repetitive partial or complete upper airway obstruction that lead to hemodynamic changes, arousals from sleep and intermittent hypoxia. Obstructive sleep apnea activates multiple pathways that lead to vascular disease. The vascular risk imposed by obstructive sleep apnea may be mediated through the metabolic consequences of sleep-disordered breathing. There is increasing evidence that obstructive sleep apnea is independently associated with dyslipidemia, a well known vascular risk factor. However, the role of obstructive sleep apnea in causality of dyslipidemia remains to be established. Current article focuses on possible mechanisms linking obstructive sleep apnea with the development of dyslipidemia. Possible role of obstructive sleep apnea as a therapeutic target to improve dyslipidemia is also discussed. Key words: dyslipidemia - obstructive sleep apnea.

Carotid intima-media thickness is not associated with homocysteine and vitamin D levels in obstructive sleep apnea

Obstructive sleep apnea syndrome (OSA) is associated with increased vascular morbidity. Accelerated atherosclerosis might be one of the most important mechanisms linking OSA with the development of vascular disorders. Homocysteine (HCY) and vitamin D has been associated with atherogenesis. The aim of this study was to assess a possible association between the levels of HCY and vitamin D and the carotid intima-media thickness (cIMT), which is a known marker for subclinical atherosclerosis in patients with OSA. We prospectively enrolled 110 patients with the history of snoring, who underwent standard overnight polysomnography. Clinical characteristics of the population were recorded on admission and blood samples were obtained in the fasting condition following morning. Extracranial cIMT measurements were performed according to the standardized scanning protocol. A significant correlation was found between cIMT and apnea-hypopnea index (r = .276, p = .006), age (r = .486, p < .001), diabetes mellitus (r = .377, p < .001), coronary artery disease (r = .274, p = .006) and history of stroke (r = .251, p = .012). We failed to find any significant correlation between cIMT and the levels of HCY (r = .036, p = .724) or vitamin D (r = .027, p = .800). In conclusion, our data suggest that the association of cIMT with the severity of OSA can be influenced by multiple metabolic consequences of OSA including traditional and non-traditional risk factors. HCY and vitamin D do not seem to play a superior role in this process.

Association of lipoprotein subfractions with endothelial function and arterial stiffness in acute ischemic stroke

Hypercholesterolemia represents a risk factor for the development of atherosclerosis. Lipoprotein research has recently been focused on the phenomenon of atherogenic and non-atherogenic lipoproteins. The aim of this study was to explore the association of lipoprotein subfractions with a measure for endothelial function (represented by reactive hyperemia index [RHI]) and arterial stiffness (represented by augmentation index [AI]) in patients with acute ischemic stroke. We enrolled 51 patients with acute ischemic stroke. Blood samples were obtained within 24 h after the stroke onset in a fasting condition. Electrophoresis method on polyacrylamide gel was used for the analysis of plasma lipoproteins. RHI and AI was measured by peripheral arterial tonometry (EndoPAT2000 device). We failed to find any significant correlation between RHI and baseline characteristics of the population. Significant correlation was found between AI and age, hypertension, low density lipoprotein cholesterol (LDL) 1, LDL 3-7, score for anti-atherogenic risk and atherogenic profile. Age (beta = .362, p = .006) and LDL1 (beta = -0.283, p = .031) were the only independent variables significantly associated with AI in regression analysis. Significantly higher AI was found in an atherogenic lipoprotein profile compared to a non-atherogenic profile population (median 25% vs. median 11.5%, p = .043). In conclusion, our results suggest significant inverse correlation between levels of LDL 1 subfraction and measures of AI in patients with acute ischemic stroke. Significantly higher values of AI were observed in the population with an atherogenic lipoprotein profile.

Association of Sleep Disordered Breathing with Wake-Up Acute Ischemic Stroke: A Full Polysomnographic Study

STUDY OBJECTIVES

Sleep disordered breathing (SDB) is a frequent comorbidity in stroke patients. SDB is one of the independent risk factors for ischemic stroke. Conversely, stroke may contribute to SDB onset or aggravate premorbid SDB. Multiple mechanisms underlying SDB might be responsible for the development of stroke. The aim of this study was to compare polysomnographic, clinical, and laboratory characteristics of wake-up (WUS) and non-wake-up acute ischemic strokes (NWUS).

METHODS

We prospectively enrolled 88 patients with acute ischemic stroke. Clinical characteristics of the population were recorded on admission, and blood samples were obtained in the fasting condition following morning. SDB was assessed using standard overnight polysomnography in the acute phase of the stroke.

RESULTS

WUS were present in 16 patients (18.2%), and NWUS in 72 patients (81.8%). In WUS compared to NWUS, we observed significantly higher values of apnea-hypopnea index (24.8 vs. 7.6, p = 0.007), desaturation index ([DI] 26.9 vs. 8.8, p = 0.005), arousal index (22.6 vs. 13.1, p = 0.035), diastolic blood pressure (91.6 mm Hg vs. 85.2 mm Hg, p = 0.039), triglyceride levels ([TG] 1.9 mmol/L vs. 1.2 mmol/L, p = 0.049), and significantly lower levels of D-dimer (0.4 μg/L vs. 0.7 μg/L, p = 0.035). DI (CI: 1.003-1.054, p = 0.031) and TG (CI: 1.002-1.877, p = 0.049) were the only independent variables significantly associated with WUS in binary logistic regression model.

CONCLUSIONS

Although the design of our study does not prove the causal relationship between SDB and WUS, higher severity of SDB parameters in WUS supports this hypothesis.

COMMENTARY

A commentary on this article appears in this issue on page 467.

Sleep disorders in patients with multiple sclerosis

OBJECTIVE

Poor sleep is a frequent symptom in patients with multiple sclerosis (MS). The objective of the study was to assess the relationship between nocturnal polysomnographic (PSG) findings and quality of sleep, fatigue, and increased daytime sleepiness among patients with MS.

METHODS

Clinical characteristics were collected. Pittsburgh Sleep Quality Index (PSQI), Fatigue Severity Scale (FSS), Epworth Sleepiness Scale (ESS), and International Restless Legs Syndrome Rating Scale were used to assess quality of sleep, fatigue, excessive daytime sleepiness, and the presence of restless legs syndrome (RLS). All patients underwent nocturnal diagnostic PSG examination.

RESULTS

Fifty patients with MS were enrolled into the study. Age was the only independent variable significantly determining apnea-hypopnea index and desaturation index (DI) (beta = 0.369, p = 0.010, beta 0.301, p = 0.040). PSQI and ESS score were significantly higher in a population with RLS (p = 0.004, p = 0.011). FSS significantly correlated with DI (r = 0.400, p = 0.048). Presence of RLS was the only independent variable significantly determining PSQI and ESS (p = 0.005, p = 0.025). DI and presence of RLS were independent variables determining FSS (p = 0.015, p = 0.024).

CONCLUSION

Presence of RLS seems to be the main factor determining poor sleep, fatigue, and daytime somnolence. Sleep disordered breathing and its severity influences only fatigue in patients with MS.

Eclampsia as a cause of secondary non-obstructive central sleep hypoventilation

The central alveolar hypoventilation of Ondine's curse is a disorder characterized by absent or diminished ventilatory response to hypercapnia, hypoxia or both, with parallel decrease in saturation to 50%. The secondary form may begin mainly after insult that affects the brain stem. We present a case of a 24-years old primipara in the 41st gestational week with an uncomplicated course of pregnancy and with secondary non-obstructive sleeping hypoventilation which occurred after eclamptic seizure. This obstetric case provides evidence for the benefit of home BiPAP use for patients with secondary Ondine's curse.

VLA4 Gene Polymorphism and Susceptibility to Multiple Sclerosis in Slovaks

Multiple sclerosis (MS) is an inflammatory autoimmune disease occurring in genetically sensitive individuals. As migration of immune cells into the CNS is facilitated by the Very Late Antigen 4 (VLA-4) integrin molecule, the VLA4 gene may be considered as a plausible candidate genetic risk factor for susceptibility to MS. Therefore, the objective of our study was to investigate the association between two genetic polymorphisms located in the VLA4 gene and the risk of multiple sclerosis. One hundred seventeen MS patients and 165 control subjects from Slovakia were genotyped for VLA4 gene SNP polymorphisms at positions 269 (C/A) and 3061 (A/G). The same study cohorts were also genotyped for the rs3135388 polymorphism tagging the HLA-DRB1*15:01 allele, which is a known genetic factor associated with susceptibility to develop MS in many populations. Our findings show for the first time that the rs3135388 polymorphism is a strong risk factor for MS in the Slovak population. Investigation of the VLA4 gene polymorphisms revealed a significantly higher frequency of the 3061AG genotype in MS patients compared to the controls (P ≤ 0.05). We suggest that the 3061AG polymorphic variant is an independent genetic risk factor for MS development in our population as it was significantly associated with this disease. The association was also confirmed after applying multivariate logistic-regression analysis adjusted for gender, age and HLA-DRB1*15:01 positivity as possible influencing factors.

Multiple sclerosis: evaluation of purine nucleotide metabolism in central nervous system in association with serum levels of selected fat-soluble antioxidants

In the pathogenesis of demyelinating diseases including multiple sclerosis (MS) an important role is played by oxidative stress. Increased energy requirements during remyelination of axons and mitochondria failure is one of the causes of axonal degeneration and disability in MS. In this context, we analyzed to what extent the increase in purine catabolism is associated with selected blood lipophilic antioxidants and if there is any association with alterations in serum levels of coenzyme Q10. Blood serum and cerebrospinal fluid (CSF) samples from 42 patients with diagnosed MS and 34 noninflammatory neurologic patients (control group) were analyzed. Compared to control group, MS patients had significantly elevated values of all purine nucleotide metabolites, except adenosine. Serum lipophilic antioxidants γ -tocopherol, β -carotene, and coenzyme Q10 for the vast majority of MS patients were deficient or moved within the border of lower physiological values. Serum levels of TBARS, marker of lipid peroxidation, were increased by 81% in the MS patients. The results indicate that the deficit of lipophilic antioxidants in blood of MS patients may have a negative impact on bioenergetics of reparative remyelinating processes and promote neurodegeneration.

How does fingolimod (gilenya(®)) fit in the treatment algorithm for highly active relapsing-remitting multiple sclerosis?

Multiple sclerosis (MS) is a neurological disorder characterized by inflammatory demyelination and neurodegeneration in the central nervous system. Until recently, disease-modifying treatment was based on agents requiring parenteral delivery, thus limiting long-term compliance. Basic treatments such as beta-interferon provide only moderate efficacy, and although therapies for second-line treatment and highly active MS are more effective, they are associated with potentially severe side effects. Fingolimod (Gilenya(®)) is the first oral treatment of MS and has recently been approved as single disease-modifying therapy in highly active relapsing-remitting multiple sclerosis (RRMS) for adult patients with high disease activity despite basic treatment (beta-interferon) and for treatment-naïve patients with rapidly evolving severe RRMS. At a scientific meeting that took place in Vienna on November 18th, 2011, experts from ten Central and Eastern European countries discussed the clinical benefits and potential risks of fingolimod for MS, suggested how the new therapy fits within the current treatment algorithm and provided expert opinion for the selection and management of patients.

Fingolimod in the treatment algorithm of relapsing remitting multiple sclerosis: a statement of the Central and East European (CEE) MS Expert Group

Fingolimod is the first oral treatment of multiple sclerosis. It is the first-in-class sphingosine 1-phosphate receptor modulator that binds to sphingosine 1-phophate receptors on lymphocytes and via downregulation of the receptor prevents lymphocyte egress from lymphoid tissues into the circulation. This mechanism reduces the infiltration of potentially auto-aggressive lymphocytes into the central nervous system. Two large phase III studies with fingolimod have shown superior efficacy of the drug in two dosages compared to placebo and to weekly intramuscular injections of Interferon beta-1a. Among possible side effects of the drug is a transient bradycardia after the first dose of fingolimod including possible AV blockade and therefore monitoring of pulse rate and blood pressure for 6 h following the first application is needed. During treatment, attention has to be given to specific infections, elevated liver enzymes, and ophthalmologic changes. Recommendations on the use of fingolimod including safety aspects are given in this article.

1-(Oxoalkyl)-3,7,8-trialkyl-3,7-dihydro-1H-purine-2,6-diones

1-(2-Oxopropyl)-, 1-(3-oxobutyl)-, and 1-(5-oxohexyl)-3,7,8-trialkyl-3,7-dihydro-1H-purine-2,6-diones (Ia -Xa, Ib - Xb, and Ic - Xc, respectively) were prepared by alkylation of alkali metal salts of 3,7,8-trialkyl-3,7-dihydro-1H-purine-2,6-diones XI - XX to methyl vinyl ketone. The effect of the final compounds I - X on aggregation of thrombocytes and erythrocytes was investigated.