Analysis of EEG Sleep Spindle Parameters from Apnea Patients Using Massive Computing and Decision Tree

In this study, Matching Pursuit (MP) procedure is applied to the detection and analysis of EEG sleep spindles in patients evaluated for suspected OSAS. Elements having the frequency of EEG sleep spindles are selected from different dictionary sizes, with and without a frequency modulation function (chirp) for signal description. This procedure was done with high computational cost in order to find best parameters for real EEG data description. At the end we used the atom parameters as input for a decision tree-based classifier, making possible to obtain a classification according to apnea-hypopnea index group and allowing to see how atom parameters such as frequency and amplitude are affected by the presence of sleep apnea. http://dx.doi.org/10.18226/23185279.v2iss1p15In this study, Matching Pursuit (MP) procedure is applied to the detection and analysis of EEG sleep spindles in patients evaluated for suspected OSAS. Elements having the frequency of EEG sleep spindles are selected from different dictionary sizes, with and without a frequency modulation function (chirp) for signal description. This procedure was done with high computational cost in order to find best parameters for real EEG data description. At the end we used the atom parameters as input for a decision tree-based classifier, making possible to obtain a classification according to apnea-hypopnea index group and allowing to see how atom parameters such as frequency and amplitude are affected by the presence of sleep apnea. http://dx.doi.org/10.18226/23185279.v2iss1p1

WHOQOL-OLD assessment of quality of life in elderly patients with Parkinson's disease: influence of sleep and depressive symptoms Qualidade de vida (WHOQOL-OLD) em idosos com doença de Parkinson: influência de sintomas do sono e depressivos

OBJECTIVE: Parkinson's disease is a neurodegenerative disease with a number of motor and non-motor features that can affect quality of life. In this study, we aimed to assess quality of life, as well as to evaluate the potential determinants of quality of life, such as sleep quality, motor and depressive symptoms, in elderly patients with Parkinson's disease. METHOD: This was a cross-sectional study in which we applied the World Health Organization Quality of Life Assessment for Older Adults in 57 Parkinson's disease patients over 60 years of age. RESULTS: Total World Health Organization Quality of Life Assessment for Older Adults score was found to be associated with Parkinson's disease severity (rs = -0.43; p < 0.001). World Health Organization Quality of Life Assessment for Older Adults scores for sensory abilities (facet 1) and social participation (facet 4) were higher among the patients with mild Parkinson's disease than among those in the more advanced stages (rs = -0.43; p < 0.001). Facet 1 scores were found to be associated with Pittsburg Sleep Quality Index and Parkinson's Disease Sleep Scale score (rp = -0.46 and rp = 0.41; p < 0.001, respectively). The Geriatric Depression Scale score showed an association with the total score on the World Health Organization Quality of Life Assessment for Older Adults (rp = -0.70; p < 0.001) CONCLUSION: Quality of life in Parkinson's disease patients can be assessed by the World Health Organization Quality of Life Assessment for Older Adults. Greater Parkinson's disease severity can worsen patient quality of life, as can the presence of depressive symptoms.<br>OBJETIVO: A doença de Parkinson é uma enfermidade neurodegenerativa com diversas manifestações motoras e não-motoras que podem provocar impacto na qualidade de vida. Este estudo teve como objetivo avaliar a qualidade de vida em pacientes com doença de Parkinson com idade superior a 60 anos por meio do questionário World Health Organization Quality of Life Assessment for Older Adults e possíveis fatores determinantes, tais como qualidade de sono, sintomas motores e depressivos. MÉTODO: Foi realizado estudo transversal avaliando a qualidade de vida pelo questionário World Health Organization Quality of Life Assessment for Older Adults em 57 pacientes com doença de Parkinson. RESULTADOS: World Health Organization Quality of Life Assessment for Older Adults total apresentou associação com a severidade da doença de Parkinson (r s= -0,43; p < 0,001). As facetas de habilidade sensorial e de participação social apresentaram maior pontuação nos indivíduos com estágio leve em comparação ao grupo com doença de Parkinson avançada. World Health Organization Quality of Life Assessment for Older Adults (faceta-I) apresentou associação com Índice de Qualidade de Sono de Pittsburg e Escala de Sono na Doença de Parkinson (r p= -0,46 e r p = 0,41; p < 0,001, respectivamente). A Escala Geriátrica de Depressão apresentou associação com World Health Organization Quality of Life Assessment for Older Adults (r p = -0,70; p < 0,001). CONCLUSÃO: A qualidade de vida em pacientes com doença de Parkinson pode ser avaliada pelo questionário World Health Organization Quality of Life Assessment for Older Adults e foi demonstrado que a severidade da doença de Parkinson e os sintomas depressivos podem comprometer negativamente a qualidade de vida

Synchronization and Propagation of Global Sleep Spindles.

Sleep spindles occur thousands of times during normal sleep and can be easily detected by visual inspection of EEG signals. These characteristics make spindles one of the most studied EEG structures in mammalian sleep. In this work we considered global spindles, which are spindles that are observed simultaneously in all EEG channels. We propose a methodology that investigates both the signal envelope and phase/frequency of each global spindle. By analysing the global spindle phase we showed that 90% of spindles synchronize with an average latency time of 0.1 s. We also measured the frequency modulation (chirp) of global spindles and found that global spindle chirp and synchronization are not correlated. By investigating the signal envelopes and implementing a homogeneous and isotropic propagation model, we could estimate both the signal origin and velocity in global spindles. Our results indicate that this simple and non-invasive approach could determine with reasonable precision the spindle origin, and allowed us to estimate a signal speed of 0.12 m/s. Finally, we consider whether synchronization might be useful as a non-invasive diagnostic tool

Loss of sleep spindle frequency deceleration in Obstructive Sleep Apnea

Objective: Sleep spindles have been suggested as surrogates of thalamo-cortical activity. Internal frequency modulation within a spindle's time frame has been demonstrated in healthy subjects, showing that spindles tend to decelerate their frequency before termination. We investigated internal frequency modulation of slow and fast spindles according to Obstructive Sleep Apnea (OSA) severity and brain topography. Methods: Seven non-OSA subjects and 21 patients with OSA contributed with 30 min of Non-REM sleep stage 2, subjected to a Matching pursuit procedure with Gabor chirplet functions for automatic detection of sleep spindles and quantification of sleep spindle internal frequency modulation (chirp rate). Results: Moderate OSA patients showed an inferior percentage of slow spindles with deceleration when compared to Mild and Non-OSA groups in frontal and parietal regions. In parietal regions, the percentage of slow spindles with deceleration was negatively correlated with global apnea-hypopnea index (r s = -0.519, p = 0.005). Discussion: Loss of physiological sleep spindle deceleration may either represent a disruption of thalamo-cortical loops generating spindle oscillations or some compensatory mechanism, an interesting venue for future research in the context of cognitive dysfunction in OSA. Significance: Quantification of internal frequency modulation (chirp rate) is proposed as a promising approach to advance description of sleep spindle dynamics in brain pathology. © 2013 International Federation of Clinical Neurophysiology

Analysis of EEG sleep spindle parameters from apnea patients using massive computing and decision tree

In this study, Matching Pursuit (MP) procedure is applied to the detection and analysis of EEG sleep spindles in patients evaluated for suspected OSAS. Elements having the frequency of EEG sleep spindles are selected from different dictionary sizes, with and without a frequency modulation function (chirp) for signal description. This procedure was done with high computational cost in order to find best parameters for real EEG data description. At the end we used the atom parameters as input for a decision tree-based classifier, making possible to obtain a classification according to apnea-hypopnea index group and allowing to see how atom parameters such as frequency and amplitude are affected by the presence of sleep apnea

Scatter-plot for spindle chirp in different channels.

<p>We can observe that correlation decreases as we consider more distant channels. Relative intensity is represented by the color scale bar displayed below.</p

Scatter-plot for spindle durations in different channels.

<p>We can observe that correlation decreases as we consider more distant channels. Relative intensity is represented by the color scale bar displayed below.</p