Fenomenologinen tutkimus video-EEG potilaiden kohtauskokemuksista

Tässä fenomenologisessa tutkimuksessa kuvaillaan Video-EEG –tutkimukseen (VEEG) tulevien potilaiden kokemuksia kohtauksistaan. Tutkimusasetelmana on käytetty fenomenologiseen psykologiaan kuuluvaa Giorgin menetelmää soveltaen sitä hoitotieteen tutkimukseen. Tutkimuksen tarkoituksena oli kuvailla neurologisten kohtausoireiden vuoksi VEEG-tutkimukseen tulleiden potilaiden kokemuksia kohtauksistaan ja tunnistaa sekä kuvailla kokemukseen liittyviä tekijöitä. Tutkimuksen tavoitteena oli lisäta terveydenhoitohenkilökunnan ymmärrystä neurologisia kohtausoireita saavien ihmisten ohjaustarpeista. Materiaali kerättiin kahdeksalta potilaalta avoimilla haastatteluilla ja analysoitiin Giorgin analyysimenetelmällä. Aineistoon yhdistettiin kliinisen neurofysiologin lausunto ja muodostettiin kokemuskertomukset. Aineistosta tunnistettiin fenomenologista reduktiota käyttäen keskeiset kohtauksiin ja sairauteen liittyvät kokemukset. Käsitteiden suhdetta toisiinsa ja merkitystä sopeutumiselle analysoitiin käyttäen apuna Uncertainty in illness -mallia. Keskeisten kokemusten pohjalta toteutettiin kirjallisuushaku, jonka tuloksia reflektoitiin tämän tutkimuksen tuloksiin. Aineistosta muodostui kolme erillistä kokemuskertomusta: kertomus konkreettisista tapahtumista, kokemus hallinnan menettämisestä ja kokemus sairauden kanssa elämisesta. Keskeisiksi kokemussisällöiksi tunnistettiin kokemus terveysongelman hallinnasta, kokemus hallinnan menettämisestä, kokemus ympäristön negatiivisesta suhtautumisesta ja huoli läheisistä. Aikaisempaa tutkimusta löytyi kokemuksista terveysongelman hallinnasta ja hallinnan menetyksestä sekä ympäristön suhtautumisesta.

Fenomenologinen tutkimus video-EEG potilaiden kohtauskokemuksista

Tässä fenomenologisessa tutkimuksessa kuvaillaan Video-EEG –tutkimukseen (VEEG) tulevien potilaiden kokemuksia kohtauksistaan. Tutkimusasetelmana on käytetty fenomenologiseen psykologiaan kuuluvaa Giorgin menetelmää soveltaen sitä hoitotieteen tutkimukseen. Tutkimuksen tarkoituksena oli kuvailla neurologisten kohtausoireiden vuoksi VEEGtutkimukseen tulleiden potilaiden kokemuksia kohtauksistaan ja tunnistaa sekä kuvailla kokemukseen liittyviä tekijöitä. Tutkimuksen tavoitteena oli lisätä terveydenhoitohenkilökunnan ymmärrystä neurologisia kohtausoireita saavien ihmisten ohjaustarpeista. Materiaali kerättiin kahdeksalta potilaalta avoimilla haastatteluilla ja analysoitiin Giorgin analyysimenetelmällä. Aineistoon yhdistettiin kliinisen neurofysiologin lausunto ja muodostettiin kokemuskertomukset. Aineistosta tunnistettiin fenomenologista reduktiota käyttäen keskeiset kohtauksiin ja sairauteen liittyvät kokemukset. Käsitteiden suhdetta toisiinsa ja merkitystä sopeutumiselle analysoitiin käyttäen apuna Uncertainty in illness -mallia. Keskeisten kokemusten pohjalta toteutettiin kirjallisuushaku, jonka tuloksia reflektoitiin tämän tutkimuksen tuloksiin. Aineistosta muodostui kolme erillistä kokemuskertomusta: kertomus konkreettisista tapahtumista, kokemus hallinnan menettämisestä ja kokemus sairauden kanssa elämisestä. Keskeisiksi kokemussisällöiksi tunnistettiin kokemus terveysongelman hallinnasta, kokemus hallinnan menettämisestä, kokemus ympäristön negatiivisesta suhtautumisesta ja huoli läheisistä. Aikaisempaa tutkimusta löytyi kokemuksista terveysongelman hallinnasta ja hallinnan menetyksestä sekä ympäristön suhtautumisesta.

EEG spike source localization before and after surgery for temporal lobe epilepsy: a BOLD EEG-fMRI and independent component analysis study

Simultaneous measurements of EEG-functional magnetic resonance imaging (fMRI) combine the high temporal resolution of EEG with the distinctive spatial resolution of fMRI. The purpose of this EEG-fMRI study was to search for hemodynamic responses (blood oxygen level-dependent - BOLD responses) associated with interictal activity in a case of right mesial temporal lobe epilepsy before and after a successful selective amygdalohippocampectomy. Therefore, the study found the epileptogenic source by this noninvasive imaging technique and compared the results after removing the atrophied hippocampus. Additionally, the present study investigated the effectiveness of two different ways of localizing epileptiform spike sources, i.e., BOLD contrast and independent component analysis dipole model, by comparing their respective outcomes to the resected epileptogenic region. Our findings suggested a right hippocampus induction of the large interictal activity in the left hemisphere. Although almost a quarter of the dipoles were found near the right hippocampus region, dipole modeling resulted in a widespread distribution, making EEG analysis too weak to precisely determine by itself the source localization even by a sophisticated method of analysis such as independent component analysis. On the other hand, the combined EEG-fMRI technique made it possible to highlight the epileptogenic foci quite efficiently.

Effect of aerobic training on EEG alpha asymmetry and depressive symptoms in the elderly: a 1-year follow-up study

The effect of physical exercise on the treatment of depressive elderly adults has not been investigated thus far in terms of changes in cortical hemispheric activity. The objective of the present study was to identify changes in depressive symptoms, quality of life, and cortical asymmetry produced by aerobic activity. Elderly subjects with a diagnosis of major depressive disorder (DSM-IV) were included. Twenty patients (70% females, 71 ± 3 years) were divided into an exercise group (pharmacological treatment plus aerobic training) and a control group (undergoing pharmacological treatment) in a quasi-experimental design. Pharmacological treatment was maintained stable throughout the study (antidepressants and anxiolytics). Subjects were evaluated by depression scales (Beck Depression Inventory, Hamilton Depression Rating Scale, Montgomery-Asberg Depression Rating Scale) and the Short Form Health Survey-36, and electroencephalographic measurements (frontal and parietal alpha asymmetry) before and after 1 year of treatment. After 1 year, the control group showed a decrease in cortical activity on the right hemisphere (increase of alpha power), which was not observed in the exercise group. The exercise group showed a significant decrease of depressive symptoms, which was not observed in the control group. This result was also accompanied by improved treatment response and remission rate after 1 year of aerobic exercise associated with treatment. This study provides support for the effect of aerobic training on alpha activity and on depressive symptoms in elderly patients. Exercise facilitates the treatment of depressive elderly adults, leading to clinical and physical improvement and protecting against a decrease in cortical activity.

Detection of Epilepsy with a Commercial EEG Headband

Epilepsy is a chronic brain disorder, characterized by reoccurring seizures. Automatic sei-zure detector, incorporated into a mobile closed-loop system, can improve the quality of life for the people with epilepsy. Commercial EEG headbands, such as Emotiv Epoc, have a potential to be used as the data acquisition devices for such a system. In order to estimate that potential, epileptic EEG signals from the commercial devices were emulated in this work based on the EEG data from a clinical dataset. The emulated characteristics include the referencing scheme, the set of electrodes used, the sampling rate, the sample resolution and the noise level. Performance of the existing algorithm for detection of epileptic seizures, developed in the context of clinical data, has been evaluated on the emulated commercial data. The results show, that after the transformation of the data towards the characteristics of Emotiv Epoc, the detection capabilities of the algorithm are mostly preserved. The ranges of acceptable changes in the signal parameters are also estimated.

Charting developmental EEG gamma changes in the auditory modality /

The oscillation of neuronal circuits reflected in the EEG gamma frequency may be fundamental to the perceptual process referred to as binding (the integration of various thoughts and perceptions into a coherent picture). The aim of our study was to expand our knowledge of the developmental course ofEEG gamma in the auditory modality. 2 We investigated EEG 40 Hz gamma band responses (35.2 to 43.0 Hz) using an auditory novelty oddball paradigm alone and with a visual-number-series distracter task in 208 participants as a function of age (7 years to adult) at 9 sites across the sagital and lateral axes (F3, Fz, F4, C3, Cz, C4, P3, Pz, P4). Gamma responses were operationally defined as change in power or a change in phase synchrony level from baseline within two time windows. The evoked gamma response was defined as a significant change from baseline occurring between 0 to 150 ms after stimulus onset; the induced gamma response was measured from 250 to 750 ms after stimulus onset. A significant evoked gamma band response was found when measuring changes in both power and phase synchrony. The increase in both measures was maximal at frontal regions. Decreases in both measures were found when participants were distracted by a secondary task. For neither measure were developmental effects noted. However, evoked gamma power was significantly enhanced with the presentation of a novel stimulus, especially at the right frontal site (F4); frontal evoked gamma phase synchrony also showed enhancement for novel stimuli but only for our two oldest age groups (16-18 year olds and adults). Induced gamma band responses also varied with task-dependent cognitive stimulus properties. In the induced gamma power response in all age groups, target stimuli generated the highest power values at the parietal region, while the novel stimuli were always below baseline. Target stimuli increased induced synchrony in all regions for all participants, but the novel stimulus selectively affected participants dependent on their age and gender. Adult participants, for example, exhibited a reduction in gamma power, but an increase in synchrony to the novel stimulus within the same region. Induced gamma synchrony was more sensitive to the gender of the participant than was induced gamma power. While induced gamma power produced little effects of age, gamma synchrony did have age effects. These results confirm that the perceptual process which regulates gamma power is distinct from that which governs the synchronization for neuronal firing, and both gamma power and synchrony are important factors to be considered for the "binding" hypothesis. However, there is surprisingly little effect of age on the absolute levels of or distribution of EEG gamma in the age range investigated.

A microanalysis of EMG and EEG changes during the sleep onset period (SOP) : a theoretical investigation with practical applications /

The present study has both theoretical and practical aspects. The theoretical intent of the study was to closely examine the relationship between muscle activity (EMG) and EEG state during the process of falling asleep. Sleep stages during sleep onset (SO) have been generally defined with regards to brain wave activity (Recht schaff en & Kales (1968); and more precisely by Hori, Hayashi, & Morikawa (1994)). However, no previous study has attempted to quantify the changes in muscle activity during this same process. The practical aspect of the study examined the reliability ofa commercially developed wrist-worn alerting device (NovAlert™) that utilizes changes in muscle activity/tension in order to alert its user in the event that he/she experiences reduced wakefulness that may result in dangerous consequences. Twelve female participants (aged 18-42) sp-ent three consecutive nights in the sleep lab ("Adaptation", "EMG", and "NOVA" nights). Each night participants were given 5, twenty-minute nap opportunities. On the EMG night, participants were allowed to fall asleep freely. On the NOV A night, participants wore the Nov Alert™ wrist device that administered a Psychomotor Vigilance Test (PVT) when it detected that muscle activity levels had dropped below baseline. Nap sessions were scored using Hori's 9-stage scoring system (Hori et aI, 1994). Power spectral analyses (FFT) were also performed. Effects ofthe PVT administration on EMG and EEG frequencies were also examined. Both chin and wrist EMG activity showed reliable and significant decline during the early stages ofHori staging (stages HO to H3 characterized by decreases in alpha activity). All frequency bands studied went through significant changes as the participants progressed through each ofHori's 9 SO stages. Delta, theta, and sigma activity increased later in the SO continuum while a clear alpha dominance shift was noted as alpha activity shifted from the posterior regions of the brain (during Hori stages HO to H3) to the anterior portions (during Hori stages H7 to H9). Administration of the PVT produced significant increases in EMG activity and was effective in reversing subjective drowsiness experienced during the later stages of sleep onset. Limitations of the alerting effects of the PVTs were evident following 60 to 75 minutes of use in that PVTs delivered afterwards were no longer able to significantly increase EMG levels. The present study provides a clearer picture of the changes in EMG and EEG during the sleep onset period while testing the efficacy of a commercially developed alerting device. EMG decreases were found to begin during Hori stage 0 when EEG was - dominated by alpha wave activity and were maximal as Hori stages 2 to 5 were traversed (coincident with alpha and beta activity). This signifies that EMG decrements and the loss of resting alpha activity are closely related. Since decreased alpha has long been associated with drowsiness and impending sleep, this investigation links drops in muscle tone with sleepiness more directly than in previous investigations. The EMG changes were reliably demonstrated across participants and the NovAlert™ detected the EMG decrements when Hori stage 3 was entered. The alerting vibrations produced by the NovAlert™ occurred early enough in the SO process to be of practical importance as a sleepiness monitoring and alerting device.

Age-Related Changes in Visual Spatial Working Memory Cognits: Frontal-Parietal EEG Coherence During Delay

This study explored changes in scalp electrophysiology across two Working Memory (WM) tasks and two age groups. Continuous electroencephalography (EEG) was recorded from 18 healthy adults (18-34 years) and 12 healthy adolescents (14-17) during the performance of two Oculomotor Delayed Response (ODR) WM tasks; (i.e. eye movements were the metric of motor response). Delay-period, EEG data in the alpha frequency was sampled from anterior and parietal scalp sites to achieve a general measure of frontal and parietal activity, respectively. Frontal-parietal, alpha coherence was calculated for each participant for each ODR-WM task. Coherence significantly decreased in adults moving across the two ODR tasks, whereas, coherence significantly increased in adolescents moving across the two ODR tasks. The effects of task in the adolescent and adult groups were large and medium, respectively. Within the limits of this study, the results provide empirical support that WM development during adolescence include complex, qualitative, change.

El vídeo en el entrenamiento de la técnica del fútbol en jugadores de 12 años por Mario Wilfredo Ayllón Salas

Tesis (Maestría en Ciencias del Ejercicio con Especialidad en Deporte de Alto Rendimiento) U.A.N.L.

Control of a tibio-femoral virtual joint by means of a hybrid EEG-EMG scheme.

Tesis (Master of Science in Electrical Engineering) UANL, 2014.

Étude de l'EEG quantifié en éveil et en sommeil chez des adolescents présentant un trouble anxieux

Les troubles anxieux sont parmi les troubles psychiatriques les plus souvent diagnostiqués chez les adolescents. Ces troubles sont souvent accompagnés de nombreuses comorbidités, dont des difficultés de sommeil. L’objectif principal de cette thèse est de caractériser l’activité corticale à l’éveil et pendant le sommeil à l’aide de l’EEG quantifié chez une population d’adolescents présentant un trouble anxieux, et de la comparer à un groupe témoin d’adolescents. Dans un second temps, on cherche à savoir si l’activité EEG des patients anxieux corrèle avec différentes mesures cliniques. Deux études permettent de répondre à ces objectifs, une première portant sur l’activité EEG au cours de l’éveil, et une seconde portant sur l’activité EEG au cours du sommeil (SL et SP). La première étude démontre que l’activité EEG des deux groupes ne présente pas de différence à l’EEG le soir. Par contre, le matin, les patients anxieux présentent une activité significativement supérieure à celle des contrôles aux électrodes centrales (0,75-10 Hz et 13-20 Hz) ainsi qu’aux électrodes occipitales (2,5-7,75 Hz). Dans la seconde étude, nous avons analysé l’activité EEG absolue et relative en SL et en SP. Nous avons trouvé une activité absolue significativement supérieure à l’EEG de la région centrale chez les participants du groupe anxieux : en SLP (stades 3 et 4) sur l’ensemble des bandes de fréquence, en stade 2 sur les bandes de fréquence thêta, alpha et beta seulement. Finalement, en SP, les différences sont trouvées en alpha et beta, et non en thêta et delta. Les résultats obtenus à ces deux études suggèrent la présence de mécanismes de synchronisation et de filtrage inadéquats au niveau de la boucle thalamo-corticale, entraînant une hypervigilance du SNC. Quant aux corrélations entre l’activité EEG et les mesures cliniques, les résultats obtenus dans les deux études révèlent que les fréquences lentes (thêta et delta) de l’activité d’éveil le matin corrèlent à la fois avec l’anxiété de trait et d’état et les fréquences rapides (Alpha et Beta) de l’EEG du sommeil corrèlent sélectivement avec l’anxiété d’état. Il semble donc exister un lien entre les mesures cliniques et l’activité EEG. Une hausse d’activité EEG pourrait être un indicateur de la sévérité accrue des symptômes anxieux.

Étude de L'EEG quantifié au cours du sommeil paradoxal dans le trouble du spectre autistique

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Topographie de l’activité EEG en fuseaux au cours du sommeil chez des enfants et adultes autistes

Les fuseaux de sommeil sont des ondes électroencéphalographiques reflétant les mécanismes électrophysiologiques de protection du sommeil. Les adultes autistes ont un sommeil léger et moins de fuseaux de sommeil que des adultes neurotypiques. L’étude vérifie si les enfants autistes montrent également moins de fuseaux de sommeil que les enfants neurotypiques et documente leur évolution avec l’âge. Nous avons enregistré le sommeil de 34 adultes (16 autistes) et 26 enfants (13 autistes) et comparé la quantité de fuseaux de sommeil enregistrés aux électrodes préfrontales (Fp1, Fp2) et centrales (C3, C4). Les deux groupes montrent une diminution similaire des fuseaux en vieillissant. Le groupe d’enfants autistes montre moins de fuseaux que le groupe témoin aux électrodes Fp2 et C4; les adultes autistes montrent significativement moins de fuseaux que les adultes contrôles aux deux électrodes centrales. Le mauvais sommeil des autistes pourrait être causé par une faible protection du sommeil déjà présente en bas âge.

Hemodynamic changes during posterior epilepsies: an eeg-fnirs study

Posterior epilepsies are relatively rare, mainly suspected clinically by the presence of visual auras. Functional near-infrared spectroscopy (fNIRS) is an emerging non-invasive imaging technique that has the potential to monitor hemodynamic changes during epileptic activity. Combined with electroencephalography (EEG), 9 patients with posterior epilepsies were recorded using EEG-fNIRS with large sampling (19 EEG electrodes and over 100 fNIRS channels). Spikes and seizures were carefully marked on EEG traces, and convolved with a standard hemodynamic response function for general linear model (GLM) analysis. GLM results for seizures (in 3 patients) and spikes (7 patients) were broadly sensitive to the epileptic focus in 7/9 patients, and specific in 5/9 patients with fNIRS deoxyhemoglobin responses lateralized to the correct lobe, and to plausible locations within the occipital or parietal lobes. This work provides evidence that EEG-fNIRS is a sensitive technique for monitoring posterior epileptic activity.

fNIRS-EEG study of focal interictal epileptiform discharges

Functional near-infrared spectroscopy (fNIRS) acquired with electroencephalography (EEG) is a relatively new non-invasive neuroimaging technique with potential for long term monitoring of the epileptic brain. Simultaneous EEG-fNIRS recording allows the spatio-temporal reconstruction of the hemodynamic response in terms of the concentration changes in oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) associated with recorded epileptic events such as interictal epileptic discharges (IEDs) or seizures. While most previous studies investigating fNIRS in epilepsy had limitations due to restricted spatial coverage and small sample sizes, this work includes a sufficiently large number of channels to provide an extensive bilateral coverage of the surface of the brain for a sample size of 40 patients with focal epilepsies. Topographic maps of significant activations due to each IED type were generated in four different views (dorsal, frontal, left and right) and were compared with the epileptic focus previously identified by an epileptologist. After excluding 5 patients due to the absence of IEDs and 6 more with mesial temporal foci too deep for fNIRS, we report that significant HbR (respectively HbO) concentration changes corresponding to IEDs were observed in 62% (resp. 38%) of patients with neocortical epilepsies. This HbR/HbO response was most significant in the epileptic focus region among all the activations in 28%/21% of patients.