EEG and ECG Microstructure Markers During Apnea Transition Phases in Central and Obstructive Sleep Apnea

Öz

This study aimed to characterize EEG- and ECG-derived microstructural markers during apnea transitions in central sleep apnea (CSA) and obstructive sleep apnea (OSA), and to examine how these transient dynamics vary across sleep stages and apnea severity. Polysomnography data from 32 male patients (16 CSA, 16 OSA) were retrospectively analyzed. EEG sub-band energies (delta, theta, alpha, beta), pulse transit time (PTT), Hjorth parameters, and frequency-domain HRV (LF/HF) were computed for pre-apnea, intra-apnea, and post-apnea epochs. Patients were additionally stratified by AHI. Group comparisons were performed using parametric and non-parametric tests with Bonferroni adjustment. OSA and CSA demonstrated distinct electrophysiological patterns. CSA showed increasing EEG sub-band power and decreasing PTT from pre- to intra-apnea, indicating rapid autonomic adjustment with minimal sleep architecture disruption. OSA exhibited reduced EEG power, lengthened PTT, and greater beta activation during apnea, consistent with arousal-like intrusions. Stage-specific analysis revealed that REM sleep displayed the most pronounced transitions, marked by delta–theta enhancement and alpha–beta suppression. In N2 and N3, delta activity showed characteristic divergence across apnea intervals, highlighting unique microstructural adaptations within each stage. High-resolution EEG and ECG features provide complementary insights into the physiological mechanisms distinguishing OSA from CSA. Event-level EEG microstructures captured transient cortical dynamics not visible in conventional scoring, suggesting their potential value as early biomarkers of respiratory instability. These findings may support improved diagnostic accuracy and individualized management strategies in sleep apnea.

Anahtar Kelimeler

• Sleep apnea
• EEG
• ECG
• microstructure
• HRV
• pulse transit time
• apnea transitions
• spectral analysis

Merkezi ve Obstrüktif Uyku Apnesinde Apne Geçiş Evrelerinde EEG ve EKG Mikroyapı Belirteçleri

Öz

Bu çalışma, santral uyku apnesi (CSA) ve obstrüktif uyku apnesi (OSA) sırasında meydana gelen apne geçişlerinde EEG ve EKG’den türetilen mikroyapı belirteçleri tanımlamayı ve bu geçici dinamiklerin uyku evreleri ile apne şiddetine göre nasıl değiştiğini incelemeyi amaçlamıştır. Toplam 32 erkek hastaya ait tam gece polisomnografi kayıtları (16 CSA, 16 OSA) geriye dönük olarak analiz edilmiştir. Pre-apne, intra-apne ve post-apne epokları için EEG alt bant enerjileri (delta, teta, alfa, beta), nabız geçiş zamanı (PTT), Hjorth parametreleri ve frekans alanı HRV (LF/HF) değerleri hesaplanmıştır. Hastalar ayrıca AHI gruplarına göre sınıflandırılmıştır. Grup karşılaştırmaları parametrik ve parametrik olmayan testlerle, Bonferroni düzeltmesi kullanılarak yapılmıştır. OSA ve CSA arasında belirgin elektrofizyolojik farklılıklar gözlenmiştir. CSA’da pre-apneden intra-apneye geçişte EEG alt bant güçleri artarken, PTT azalmış; bu durum minimal uyku mimarisi bozulmasıyla birlikte hızlı otonom yanıtları göstermiştir. OSA’da ise EEG gücü azalmış, PTT uzamış ve apne sırasında beta aktivitesi artmış olup, bu durum uyanıklık benzeri geçişlerle uyumludur. Evreye özgü analizler, özellikle REM uykusunda delta–teta artışı ve alfa–beta baskılanmasıyla belirgin geçişler olduğunu ortaya koymuştur. N2 ve N3 evrelerinde delta aktivitesinin apne dönemlerine göre karakteristik değişimleri, evreye özgü mikroyapı adaptasyonları göstermiştir. Yüksek çözünürlüklü EEG ve EKG özellikleri, CSA ve OSA’yı ayırt eden fizyolojik mekanizmalar hakkında tamamlayıcı bilgiler sunmaktadır. Olay düzeyindeki EEG mikroyapıları geleneksel skorlamada görünmeyen geçici kortikal dinamikleri yakalayarak solunumsal instabilitenin erken belirteçleri olabilir. Bu bulgular, uyku apnesinin tanısal doğruluğunu artırmaya ve bireyselleştirilmiş tedavi stratejilerini desteklemeye katkı sağlayabilir.

Anahtar Kelimeler

• Uyku apnesi
• EEG
• EKG
• mikroyapı KHD (kalp hızı değişkenliği)
• nabız geçiş zamanı
• apne geçişleri
• spektral analiz

Kaynakça

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