P030 The effects of continuous positive airway pressure (CPAP) therapy in moderate to severe obstructive sleep apnea (OSA): A high-density electroencephalography (EEG) study

Abstract Introduction A previous high-density EEG investigation in OSA showed regional sleep EEG deficits particularly slow wave activity (SWA) in the parietal region. It is unclear whether CPAP treatment can reverse local sleep EEG abnormalities, and whether any recovery is related to improved cognitive function. Methods Fifteen males with moderate-severe OSA (age 50.4±6.5yrs, AHI 51.7±23.5/h) underwent polysomnography with 256-channel high-density EEG at baseline and following 3 months of CPAP. Tasks assessing cognitive performance and sleep-dependent memory were administered. Topographical spectral power maps were calculated for standard frequency ranges for sleep stages. Differences in normalized power between baseline and treatment were determined by statistical nonparametric mapping. Results In 11 CPAP compliant patients (data loss: intolerant of CPAP[n=3]/high-density EEG [n=1]), total sleep time did not change after CPAP but N1 (baseline vs. treatment: 66.9 vs. 39.5 mins, p=0.008) and N2 (195.0 vs. 150.6 mins, p=0.002) sleep was lower and N3 (89.8 vs. 128.7 mins, p=0.003) was higher. Topographic high-density EEG analysis revealed a regional increase in SWA (1–4.5Hz) during N3 sleep in a cluster of 22 electrodes overlying the parietal cortex (paired t-test, t(10)=-3.9, p=0.0029). The change in N3 SWA in the parietal cluster after CPAP was correlated with improved overnight procedural memory on the motor sequence task (rho=0.79, p=0.03) and better executive functioning (Stroop accuracy, rho=0.73, p=0.01). Conclusion CPAP treatment reduces localised deficits in sleep EEG, and specific regional recovery relates to short-term improvements in memory and executive function. These data also highlight the potential for long-term therapeutic effects on cognitive outcomes.

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0669 The Effects Of Continuous Positive Airway Pressure Therapy In Moderate To Severe Obstructive Sleep Apnea: A High-density EEG Study

SLEEP ◽

10.1093/sleep/zsaa056.665 ◽

2020 ◽

Vol 43 (Supplement_1) ◽

pp. A255-A255

Author(s):

A L D’Rozario ◽

C Kao ◽

A E Mullins ◽

N Memarian ◽

B Yee ◽

...

Keyword(s):

Memory Consolidation ◽

Declarative Memory ◽

Nrem Sleep ◽

High Density ◽

Sleep Eeg ◽

Therapeutic Effects ◽

Topographic Analysis ◽

Pressure Therapy ◽

Power Maps ◽

Eeg Power

Abstract Introduction A previous high-density electroencephalography (EEG) investigation in asymptomatic OSA showed regional deficits in sleep EEG power particularly slow wave activity (SWA) during NREM sleep in the parietal region. It is unclear whether treatment with CPAP can reverse local sleep EEG abnormalities in OSA, and whether any recovery is related to improvement in sleep-dependent memory consolidation. Methods Fifteen male participants (age 50.4±6.5yrs, AHI 51.7±23.5/h) with moderate-severe OSA (AHI>15/h) underwent overnight polysomnography with 256-channel high-density EEG at baseline and following 3 months of CPAP therapy. A word paired associates declarative memory task was administered before and after sleep. After artefact removal, spectral analysis was performed for all channels. Topographical power maps were calculated for standard frequency ranges for NREM sleep (164 channels within a 0.57 radius from the vertex). Maps were compared using both absolute and normalized power (z-scores computed for each subject) and differences between baseline and treatment were determined by statistical nonparametric mapping. Results In 11 CPAP compliant patients (intolerant of CPAP [n=3]/high-density EEG [n=1]), analysis of polysomnographic variables showed that total sleep time did not differ but N1 (baseline vs. treatment: 66.9 vs. 39.5 mins,p=0.008) and N2 (195.0 vs. 150.6 mins,p=0.002) sleep was lower and N3 (89.8 vs. 128.7 mins,p=0.003) was higher after CPAP. Topographic analysis of high-density EEG data revealed a regional increase in SWA (1-4.5Hz) EEG power during N3 sleep in a cluster of electrodes overlying the centro-parietal cortex (cluster mean t-value=2.87,p=0.02). The change in overnight declarative memory consolidation (% recognition) after CPAP was significantly correlated with the change in slow spindle frequency activity in frontal regions (cluster mean r=0.875,p=0.003). Conclusion CPAP treatment may enhance localised deficits in sleep EEG activity in OSA, and specific regional recovery may translate to memory improvements in the short-term. These data also highlight the potential for long-term therapeutic effects on cognitive outcomes in OSA. Support

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nCPAP Treatment of Obstructive Sleep Apnea Increases Slow Wave Sleep in Prefrontal EEG

Clinical EEG and Neuroscience ◽

10.1177/155005940703800311 ◽

2007 ◽

Vol 38 (3) ◽

pp. 148-154 ◽

Cited By ~ 4

Author(s):

Veera Eskelinen ◽

Toomas Uibu ◽

Sari-Leena Himanen

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Treatment Period ◽

Slow Wave ◽

Slow Wave Sleep ◽

Sleep Stage ◽

Sleep Eeg ◽

Sleep Stages ◽

Obstructive Sleep ◽

Sleep Stage Scoring

According to standard sleep stage scoring, sleep EEG is studied from the central area of parietal lobes. However, slow wave sleep (SWS) has been found to be more powerful in frontal areas in healthy subjects. Obstructive sleep apnea syndrome (OSAS) patients often suffer from functional disturbances in prefrontal lobes. We studied the effects of nasal Continuous Positive Airway Pressure (nCPAP) treatment on sleep EEG, and especially on SWS, in left prefrontal and central locations in 12 mild to moderate OSAS patients. Sleep EEG was recorded by polysomnography before treatment and after a 3 month nCPAP treatment period. Recordings were classified into sleep stages. No difference was found in SWS by central sleep stage scoring after the nCPAP treatment period, but in the prefrontal lobe all night S3 sleep stage increased during treatment. Furthermore, prefrontal SWS increased in the second and decreased in the fourth NREM period. There was more SWS in prefrontal areas both before and after nCPAP treatment, and SWS increased significantly more in prefrontal than central areas during treatment. Regarding only central sleep stage scoring, nCPAP treatment did not increase SWS significantly. Frontopolar recording of sleep EEG is useful in addition to central recordings in order to better evaluate the results of nCPAP treatment.

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Improvements in Cognitive Function and Quantitative Sleep EEG in OSA after Six Months of CPAP Treatment

SLEEP ◽

10.1093/sleep/zsac013 ◽

2022 ◽

Author(s):

Angela L D’Rozario ◽

Camilla M Hoyos ◽

Keith K H Wong ◽

Gunnar Unger ◽

Jong Won Kim ◽

...

Keyword(s):

Cognitive Function ◽

Cognitive Deficits ◽

Power Spectral Analysis ◽

Sleep Eeg ◽

Cpap Treatment ◽

Power Spectral ◽

Obstructive Sleep ◽

Before And After ◽

Slow Sleep ◽

Brain Electrophysiology

Abstract Study Objectives Untreated obstructive sleep apnea (OSA) is associated with cognitive deficits and altered brain electrophysiology. We evaluated the effect of continuous positive airway pressure (CPAP) treatment on quantitative sleep electroencephalogram (EEG) measures and cognitive function. Methods We studied 162 OSA patients (age 50±13, AHI 35.0±26.8) before and after 6 months of CPAP. Cognitive tests assessed working memory, sustained attention, visuospatial scanning and executive function. All participants underwent overnight polysomnography at baseline and after CPAP. Power spectral analysis was performed on EEG data (C3-M2) in a sub-set of 90 participants. Relative delta EEG power and sigma power in NREM and EEG slowing in REM were calculated. Spindle densities (events p/min) in N2 were also derived using automated spindle event detection. All outcomes were analysed as change from baseline. Results Cognitive function across all cognitive domains improved after six months of CPAP. In our sub-set, increased relative delta power (p<0.0001) and reduced sigma power (p=0.001) during NREM were observed after the 6-month treatment period. Overall, fast and slow sleep spindle densities during N2 were increased after treatment. Conclusions Cognitive performance was improved and sleep EEG features were enhanced when assessing the effects of CPAP. These findings suggest the reversibility of cognitive deficits and altered brain electrophysiology observed in untreated OSA following six months of treatment.

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Faculty Opinions recommendation of Daytime loop gain is elevated in obstructive sleep apnea but not reduced by CPAP treatment.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.733891425.793561226 ◽

2019 ◽

Author(s):

Jerome Dempsey

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Loop Gain ◽

Cpap Treatment ◽

Obstructive Sleep

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Investigating the Effects of Seizures on Procedural Memory Performance in Patients with Epilepsy

Brain Sciences ◽

10.3390/brainsci11020261 ◽

2021 ◽

Vol 11 (2) ◽

pp. 261

Author(s):

Frank J. van Schalkwijk ◽

Walter R. Gruber ◽

Laurie A. Miller ◽

Eugen Trinka ◽

Yvonne Höller

Keyword(s):

Temporal Lobe ◽

Declarative Memory ◽

Memory Performance ◽

Total Sample ◽

Learning Task ◽

Procedural Memory ◽

Memory Retention ◽

Motor Sequence ◽

Performance Improvements ◽

Patients With Epilepsy

Memory complaints are frequently reported by patients with epilepsy and are associated with seizure occurrence. Yet, the direct effects of seizures on memory retention are difficult to assess given their unpredictability. Furthermore, previous investigations have predominantly assessed declarative memory. This study evaluated within-subject effects of seizure occurrence on retention and consolidation of a procedural motor sequence learning task in patients with epilepsy undergoing continuous monitoring for five consecutive days. Of the total sample of patients considered for analyses (N = 53, Mage = 32.92 ± 13.80 y, range = 18–66 y; 43% male), 15 patients experienced seizures and were used for within-patient analyses. Within-patient contrasts showed general improvements over seizure-free (day + night) and seizure-affected retention periods. Yet, exploratory within-subject contrasts for patients diagnosed with temporal lobe epilepsy (n = 10) showed that only seizure-free retention periods resulted in significant improvements, as no performance changes were observed following seizure-affected retention. These results indicate general performance improvements and offline consolidation of procedural memory during the day and night. Furthermore, these results suggest the relevance of healthy temporal lobe functioning for successful consolidation of procedural information, as well as the importance of seizure control for effective retention and consolidation of procedural memory.

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EEG microstate in obstructive sleep apnea patients

Scientific Reports ◽

10.1038/s41598-021-95749-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xin Xiong ◽

Yuyan Ren ◽

Shenghan Gao ◽

Jianhua Luo ◽

Jiangli Liao ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Correlation Analysis ◽

Transition Probability ◽

Transient State ◽

Sample Entropy ◽

Sleep Stages ◽

Fluctuation Analysis ◽

Alpha Power ◽

Obstructive Sleep

AbstractObstructive sleep apnea (OSA) is a common sleep respiratory disease. Previous studies have found that the wakefulness electroencephalogram (EEG) of OSA patients has changed, such as increased EEG power. However, whether the microstates reflecting the transient state of the brain is abnormal is unclear during obstructive hypopnea (OH). We investigated the microstates of sleep EEG in 100 OSA patients. Then correlation analysis was carried out between microstate parameters and EEG markers of sleep disturbance, such as power spectrum, sample entropy and detrended fluctuation analysis (DFA). OSA_OH patients showed that the microstate C increased presence and the microstate D decreased presence compared to OSA_withoutOH patients and controls. The fifth microstate E appeared during N1-OH, but the probability of other microstates transferring to microstate E was small. According to the correlation analysis, OSA_OH patients in N1-OH showed that the microstate D was positively correlated with delta power, and negatively correlated with beta and alpha power; the transition probability of the microstate B → C and E → C was positively correlated with alpha power. In other sleep stages, the microstate parameters were not correlated with power, sample entropy and FDA. We might interpret that the abnormal transition of brain active areas of OSA patients in N1-OH stage leads to abnormal microstates, which might be related to the change of alpha activity in the cortex.

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436 Obstructive Sleep Apnea Treatment (e.g., CPAP) Differential Effects on Cognitive Performance

SLEEP ◽

10.1093/sleep/zsab072.435 ◽

2021 ◽

Vol 44 (Supplement_2) ◽

pp. A172-A173

Author(s):

Ei Hlaing ◽

Stephanie Clancy Dollinger ◽

Terry Brown

Keyword(s):

Sleep Quality ◽

Cognitive Deficits ◽

Daytime Sleepiness ◽

Short Term Memory ◽

Cognitive Tests ◽

Subjective Sleep Quality ◽

Cognitive Improvement ◽

Cpap Treatment ◽

Integrative Research ◽

Obstructive Sleep

Abstract Introduction The efficacy of CPAP treatment for cognitive improvement among patients with OSA is inconsistent. Naegele et al. (1995) found that short term memory impairment persisted even after 4 to 6 months of CPAP; O’Donoghue et al. (2012) have reported they did not find improvement in vigilance or memory; Felver-Grant (2007) found that working memory improved but not other cognitive tests. Kanbay et al. (2015) found patients improved on the MMSE scores after 3 months of CPAP treatment. Kim et al. (2018) claimed just 3 weeks of CPAP treatment improved attention, sleep quality, and excessive daytime sleepiness (EDS). CPAP therapy has little effect on the improvement of cognitive deficits associated with OSA if the patients did not complain of daytime sleepiness (Zhou et al,, 2016). Methods Both untreated OSA patients (N=19) and ApneaLinkTM- screened controls (N=16) were administered a battery of cognitive tests before the patients started using CPAP and these two conditions were tested again after 3 months of CPAP treatment. A Fisher’s Exact Chi-Square test was used to determine if there was an association between conditions (OSA patients vs. Controls) and level of performance on cognitive tests (low vs. high scores) at the baseline and after 3 months of treatment. Results Depression scores, subjective sleep quality scores (global PSQI), EDS scores (Epworth Sleepiness Scale), and mood disturbance (Profile of Mood States) decreased after 3 months of CPAP treatment just for patients. Controls (individuals without moderate or severe OSA) performed better at the second time on phonemic fluency, immediate recall memory test, and 30 minute delayed memory recall test. Conclusion The fact that patients did not do better at time 2 on any of the cognitive tests may indicate a long term effect of hypoxia on the brain. The cognitive deficits may not reverse within the first 3 months of CPAP although self-reported depressive symptoms and perception of sleep quality and positive mood have improved when patients reported they are compliant with the treatment. Support (if any) A grant from the Center for Integrative Research on Cognitive Neural Science, Southern Illinois University Carbondale was received.

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