Relation in-between autonomic cardiovascular control and central nervous system activity during sleep using spectrum-weighten frequencies

The present study is concerned with relevance of the spectrum-weighted frequencies of both heart rate variability (HRV) and electroencephalogram (EEG). The frequencies represent the balance point of power within a certain spectral range. The predictive value of the frequencies and their mutual interrelations are demonstrated with respect to different sleep stages based on data from a single case. In particular, the revealed stage-dependent relationships between frequencies from HRV and EEG suggest a close interrelation between autonomic cardiovascular control and activity of central nervous system. The results demonstrate that the easy-to-assess frequencies may provide a simple indicator of the sleep quality within the scope of comfortable patient monitorin

Contribution of Obstructive Sleep Apnoea to Cognitive Functioning of Males With Coronary Artery Disease: A Relationship With Endocrine and Inflammatory Biomarkers

IntroductionOur exploratory study aimed to determine whether obstructive sleep apnoea (OSA) could affect cognitive functioning in males with coronary artery disease (CAD), and whether such impact could be associated with changes in thyroid hormones and inflammatory marker regulation on cognitive functioning.MethodWe evaluated different endocrine and inflammatory biomarkers, including free triiodothyronine [fT3], free tetraiodothyronine [fT4], N-terminal pro-B-type natriuretic peptide [NT-pro-BNP], and high-sensitivity C-reactive protein [hs-CRP] serum levels in 328 males (x¯ = 57 ± 10 years), undergoing cardiac rehabilitation after an acute coronary event. Participants underwent full-night polysomnography and were classified in mild/non-OSA (n = 253) and OSA (n = 75) according to an apnoea-hypopnoea index ≥ 15 event/h. Cognitive functioning testing included the Digit Span Test, Digit Symbol Test (DSST), and Trail Making Test. Analyses of variance assessed the impact of OSA on cognitive functioning and possible relationships of fT3/fT4, NT-pro-BNP and with hs-CRP on cognitive measures.ResultsSignificant group (OSA, mild/non-OSA) × NT-pro-BNP (<157.0 vs. ≥157.0, ng/L) interactions were found for the DSST raw score (F(2,324) = 3.58, p = 0.014). Decomposition of interactions showed that the DSST scores of the OSA group with NT-pro-BNP ≥ 157.0 ng/L (M = 33.2; SD = 8.1) were significantly lower, p = 0.031, than those of the mild/non-OSA with NT-pro-BNP < 157.0 ng/L (M = 37.7; SD = 8.9).ConclusionThese findings indicate that males with OSA and clinically elevated NT-pro-BNP levels experienced inferior psychomotor performance compared to those without OSA and reduced NT-pro-BNP levels

A Web Based System for Sleep Disorders Management

This presentation was given at the Med-e-tel 2005 Conference in Luxembourg on April 7th, 2005.Internet as eHealth Tool: A Web-based system enabling population and physicians to learn about sleep disorders, to self-assess their sleep using an expert system including a Multidimensional Scaling algorithm to visualise the results, and to consult a physician via Internet enhancing the efficiency of diagnosis and treatment will be presented.Institute Psychophysiology and Rehabilitation, Vyduno Str. 4, Palanga, Lithuania and Vytautas Magnus University, Lithuani