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.

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.

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.

Cerebral blood flow in stroke patients with sleep apnea: any role of single-night positive airway pressure therapy?

BACKGROUND AND OBJECTIVE: Sleep-disordered breathing (SDB) is more prevalent in patients with stroke than in the population without a history of stroke. SDB is an independent risk factor for stroke. SDB impairs cerebral circulation by several mechanisms, and therefore possibly contributes to wake-up stroke. Ultrasound-tagged near-infrared spectroscopy (UT-NIRS) is a novel technology able to detect cerebral blood flow noninvasively and in real-time, displaying cerebral flow as cerebral flow index (CFI). Positive airway pressure (PAP) is the most effective approach in the treatment of SDB. We aimed to assess if single-night PAP impacts cerebral blood flow in sleep apnea patients after stroke and without a history of stroke. MATERIALS AND METHODS: 11 stroke patients and six controls with sleep apnea were enrolled. Stroke patients underwent overnight pulse oximetry within seven days after stroke. Desaturation index ≥ 15/hour was considered a positive screening. Six weeks after stroke, patients with positive screening underwent overnight polysomnography together with cerebral blood flow monitoring using UT-NIRS (diagnostic night) and also with additional PAP therapy (therapeutic night). RESULTS: The number of respiratory events decreased significantly in the group of stroke patients (apnea-hypopnea index [AHI] from 22.6±9.0 to 9.9±9.9) and controls (AHI from 58.1±14.9 to 7.0±9.7). CFI showed no significant changes between a diagnostic and therapeutic night in both groups. CONCLUSION: Despite the significant reduction of respiratory events, single-night PAP therapy does not improve overall cerebral blood flow, as defined by CFI.

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.

Pulse oximetric routine examination of sleep apnea in acute stroke (PRESS).

BACKGROUND: Sleep-disordered breathing (SDB) is present in more than 70% of stroke patients. Despite its association with increased morbidity, mortality, and reduced functional outcomes, targeted assessment of SDB in stroke patients, remain controversial. Polysomnography ("gold standard" examination) is a technically demanding and costly test with limited availability. The use of screening questionnaires is limited due to low specificity and sensitivity. Pulse oximetry seems to be a sensible alternative. Our study aimed to assess the feasibility and predictive value of routine pulse oximetric screening for assessment of SDB in patients with acute stroke. METHODS: Patients with acute stroke were enrolled in an open, prospective study. A single-night pulse oximetric assessment was used for SDB screening. Subsequently, polysomnography was performed to confirm SDB. Moderate-to-severe SDB was defined as apnea-hypopnea index ≥15. RESULTS: Out of 420 enrolled patients, refusal to undergo examination was reported in 4 and non-cooperation during the investigation in 21 subjects. The area under the curve in a receiver operating curve to predict moderate-to-severe SDB by desaturation index (DI) was 0.86 (95% CI: 0.76-0.97), and optimal DI cut-off by Youden index was 15.3. Positive pulse oximetric screening (DI ≥ 15.3) had 90.5% sensitivity and 75% specificity to predict moderate-to-severe SDB. CONCLUSIONS: Our results suggest a good adherence of acute stroke patients to the pulse oximetric screening. Pulse oximetry represents a simple, cost-effective, and sensitive examination that might be used in stroke patients as an appropriate tool for further selection for targeted diagnostic and therapeutic processes of SDB in the sleep laboratory.