25 research outputs found

    The adapted American Academy of Sleep Medicine sleep scoring criteria in one month old infants : A means to improve comparability?

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    Objective: The lack of standards induces variability in the sleep staging of infants less than two months of age. We evaluated the feasibility of the 2012 AASM sleep scoring rules for healthy one month old infants. Methods: 84 polysomnographies were scored into sleep stages with the adapted AASM criteria. The acquired sleep parameters were compared with the parameters in the literature. In addition the effect of age on sleep was studied. Results: The two independent scorers achieved substantial agreement by using the adapted AASM criteria. The infants' sleep parameters showed marked variability. The amount of active sleep was 36.7% (mean, range 21.3-54.1%), quiet sleep 41.5% (30.3-57.7%) and indeterminate sleep 21.6% (9.7-36.0%). With age sleep became more continuous, but the sleep stage percentages did not change. Our sleep parameters differed clearly from the parameters presented in the literature. Conclusions: The adapted scoring rules were reproducible. This encourages their use in clinical practice, as no uniform recommendations exist. Significance: Normal values are essential in pediatric sleep medicine and the individual variability in the sleep parameters of healthy infants advocates the standardisation of scoring methods. Here we present sleep stage normative values for one month old infants based on the AASM scoring criteria. (C) 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.Peer reviewe

    Local changes in computational non-rapid eye movement sleep depth in infants

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    Objective: Deep NREM sleep and its hallmark EEG phenomenon slow wave activity (SWA) are under homeostatic control in adults. SWA is also locally regulated as it increases in the brain areas that have been used intensively. Moreover, in children, SWA is a marker of cortical maturation. In the present study the local properties of NREM sleep depth were evaluated using the quantitative mean frequency method. We aimed to study if age is related to NREM sleep depth in young infants. In addition, we studied if young infants have local differences in their NREM sleep. Methods: Ambulatory over-night polysomnographies were recorded in 59 healthy and full-term infants at the age of one month. The infants were divided into two age groups (= 44 weeks) to allow maturational evaluations. Results: The quantitative sleep depth analysis showed differences between the age groups. In addition, there were local sleep depth differences within the age groups. Conclusions: The sleep depth change with age is most likely related to cortical maturation, whereas the local sleep depth gradients might also reflect the use-dependent properties of SWA. (C) 2017 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.Peer reviewe

    Season is related to the slow wave and sigma activity of infants and toddlers

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    Objective/Background: Slow wave activity (SWA) and sigma frequency activity (SFA) are hallmarks of NREM sleep EEG and important indicators of neural plasticity, development of the central nervous system, and cognition. However, little is known about the factors that modulate these sleep EEG activities, especially in small children. Patients/methods: We analyzed the power spectral densities of SWA (1e4 Hz) and SFA range (10e15 Hz) from six EEG derivations of 56 infants (8 months) and 60 toddlers (24 months) during their all-night sleep and during the first and the last half of night sleep. The spectral values were compared between the four seasons. Results: In the spring group of infants, compared with the darker seasons, SFA was lower in the centrooccipital EEG derivations during both halves of the night. The SWA findings of the infants were restricted to the last half of the night (SWA2) and frontally, where SWA2 was higher during winter than spring. The toddlers presented less frontal SWA2 during winter compared with autumn. Both age groups showed a reduction in both SWA and SFA towards the last half of the night. Conclusions: The sleep EEG spectral power densities are more often associated with seasons in infants’ SFA range. The results might stem from seasonally changing light exposure, but the exact mechanism warrants further study. Moreover, contrary to the adult-like increment of SFA, the SFA at both ages was lower at the last part of the night sleep. This suggests different regulation of spindle activity in infants and toddlers.Peer reviewe

    Variants in calcium voltage-gated channel subunit Alpha1 C-gene (CACNA1C) are associated with sleep latency in infants

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    Genetic variants in CACNA1C (calcium voltage-gated channel subunit alpha1 C) are associated with bipolar disorder and schizophrenia where sleep disturbances are common. In an experimental model, Cacna1c has been found to modulate the electrophysiological architecture of sleep. There are strong genetic influences for consolidation of sleep in infancy, but only a few studies have thus far researched the genetic factors underlying the process. We hypothesized that genetic variants in CACNA1C affect the regulation of sleep in early development. Seven variants that were earlier associated (genome-wide significantly) with psychiatric disorders at CACNA1C were selected for analyses. The study sample consists of 1086 infants (520 girls and 566 boys) from the Finnish CHILD-SLEEP birth cohort (geno-typed by Illumina Infinium PsychArray BeadChip). Sleep length, latency, and nightly awakenings were reported by the parents of the infants with a home-delivered questionnaire at 8 months of age. The genetic influence of CACNA1C variants on sleep in infants was examined by using PLINK software. Three of the examined CACNA1C variants, rs4765913, rs4765914, and rs2239063, were associated with sleep latency (permuted PPeer reviewe

    Vesiruton energia ja ravinteet talteen ‚Äď Elodea II -hankkeen loppuraportti

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    Kanadanvesirutto (Elodea canadensis) on haitalliseksi vieraslajiksi luokiteltu uposkasvi, joka on levinnyt satoihin j√§rviin Suomessa. Vesirutto voi kasvattaa laajoja, jopa koko j√§rven laajuisia massakasvustoja, syrj√§ytt√§√§ muita alkuper√§isi√§ lajeja, aiheuttaa hajotessaan happikatoa sek√§ heikent√§√§ j√§rvien virkistysk√§ytt√∂mahdollisuuksia. Vuosina 2019‚Äď2021 toteutetun Elodea II -hankkeen tavoitteena oli kehitt√§√§ kustannustehokkaita keinoja vesiruton poistamiseksi sek√§ biomassan ja sen sis√§lt√§mien ravinteiden hy√∂dynt√§miseksi. Vesiruton biomassan poistoon kehitettiin t√§t√§ kohdetta varten optimoitu raivausnuotta, jolla biomassan poisto onnistui hankkeen tarpeita varten. Raivausnuottaus on kuitenkin ty√∂l√§st√§ ja hidasta monine ty√∂vaiheineen, joten menetelm√§ vaatii viel√§ jatkokehityst√§. Vesiruton poiston haitalliset vaikutukset veden laatuun j√§iv√§t v√§h√§isiksi, mutta raivausnuottauksen mukana poistetut harvinaiset vesikasvit n√§yttiv√§t palautuvan nopeasti. Biomassan sis√§lt√§mien ravinteiden hy√∂dynt√§mismahdollisuutta selvitettiin k√§ytt√§m√§ll√§ sit√§ viherlannoitteena peruna- ja kokoviljas√§il√∂rehukasvustoille. Biomassan k√§sittely ja peltolevitys onnistuivat maatalouskoneilla hyvin. Biomassan lis√§yksest√§ viherlannoitteena ei kuitenkaan saatu odotettuja lannoitevaikutuksia peltokokeissa. Toisaalta siit√§ ei ollut haittaa testikohteina k√§ytetyille viljelykasveille, mink√§ perusteella peltolevitys voisi tarjota toimivan ja kustannustehokkaan ratkaisun vesiruton loppusijoitukseen. Laboratoriokokeissa vesiruton pinnalta eristettiin yli 200 erilaista mikrobia. Alustavien tulosten perusteella muutamat bakteeri-isolaatit estiv√§t tehokkaasti perunarupea aiheuttavien Streptomyces-bakteerien ja kohtalaisesti perunaseitti√§ aiheuttavan Rhizoctonia solani -sienen kasvua. Perunaseitin osalta sama vaikutus oli havaittavissa my√∂s peltokokeissa. Vesiruton soveltuvuutta biokaasuntuotannon lis√§sy√∂tteeksi sek√§ biomassan s√§il√∂nt√§mahdollisuuksia selvitettiin laboratorio- ja maatilamittakaavan kokeissa. Tavanomaiset nurmirehun korjuu- ja varastointimenetelm√§t soveltuvat biomassan k√§sittelyyn, mutta ty√∂ on hitaampaa pieneksi silppuuntuvan ja m√§r√§n materiaalin vuoksi. Biomassan paalaus biokaasulaitokselle kuljetettavaksi oli mahdollista, kun biomassa seostettiin nurmen kanssa. Pelk√§n biomassan s√§il√∂nt√§ minisiiloissa k√§ymiseen perustuvalla menetelm√§ll√§ onnistui varsin heikosti aistittavan laadun, happamuuden ja mikrobien m√§√§r√§n perusteella. K√§ymist√§ rajoittivat biomassan varsin v√§h√§inen kuiva-ainepitoisuus ja todenn√§k√∂isesti my√∂s niukka liukoisten hiilihydraattien pitoisuus. Nurmirehun lis√§ys kuitenkin edisti s√§il√∂nn√§n onnistumista. Vesiruton biomassa parantaa biokaasutuksen metaanisaantoa ja sen k√§ytt√∂ on tietyin reunaehdoin jopa kannattavaa. Toimenpiteiden kannattavuutta arvioitiin ja kehiteltiin toimintamalleja, joiden avulla voidaan luoda vesiruton poistamiseen liittyvi√§ liiketoimintamahdollisuuksia paikallisille yritt√§jille

    Neurophysiological Features of Sleep in Infants : Visual and Computational Approach

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    Vauvan uni muuttuu i√§n my√∂t√§ heijastaen keskushermoston kehityst√§. Toisaalta varhaisvaiheiden unen laadun ja m√§√§r√§n tiedet√§√§n vaikuttavan lapsen my√∂hemp√§√§n hyvinvointiin. Unen neurofysiologisen tutkimuksen keskeisen√§ tavoitteena on kartuttaa tietoa vauvan unen normaalista, i√§nmukaisesta kehityksest√§. Viimek√§dess√§ t√§ydentyv√§n tiedon avulla toivotaan saatavan entist√§ parempia keinoja neurologisen kehityksen poikkeavuuksien tunnistamiseen, jolloin niiden syihinkin voitaisiin puuttua varhain ja perustellusti. Unitutkimusten kultaisena standardina pidet√§√§n unipolygrafiaa (polysomnografia, PSG), johon valtaosa kirjallisuudessa esitetyist√§ vauvaik√§isten uniparametrien normaaliarvoista perustuu. PSG on monikanavainen, jatkuva, unenaikainen rekister√∂inti, johon sis√§ltyy EEG apukanavineen univaiheluokitusta varten ja lis√§ksi kliinisen kysymyksenasettelun mukaan valittuja muita fysiologisia signaaleja esimerkiksi hengityksen mittaamiseksi. PSG:ssa univaiheluokitus perustuu tavallisesti visuaalisiin, EEG:t√§ painottaviin luokittelukriteereihin, joita on vuosikymmenten kuluessa luotu useita hieman erilaisia vauvaik√§isille. On luultavaa, ett√§ erilaiset luokittelukriteerit korostavat julkaistujen unisuureiden vaihtelua tutkimusten v√§lill√§. Tutkimusten v√§liset erot vauvojen uniparametrien normaaliarvoissa ovatkin tunnetusti merkitt√§vi√§, mutta jo yksitt√§isten tutkimusten sis√§ll√§ uniparametreissa on paljon yksil√∂llist√§ vaihtelua. Vauvojen unen tiedet√§√§n vaihtelevan yksil√∂llisesti jopa enemm√§n kuin vanhemmilla lapsilla tai aikuisilla, mik√§ on todenn√§k√∂isesti seurausta keskushermoston ep√§kypsyydest√§, sen nopeasta kehityksest√§ ja kehitykseen liittyv√§st√§ unen jatkuvasta muuttumisesta. Johtuen terveidenkin vauvojen suurista yksil√∂llisist√§ eroista ja toisaalta eri tutkimusten v√§lisest√§ vaihtelusta vauvan normaalia ja poikkeavaa neurologista kehityst√§ ei voi erottaa toisistaan pelkkien unen perussuureiden perusteella kuin aivan √§√§rimm√§isiss√§ tapauksissa. Koska lis√§ksi perinteiseen univaiheluokitukseen perustuvalla unen rakenteen analyysilla ei voida tarkastella unen topografisia eroja tai sen kvantitatiivisia, esimerkiksi taajuuteen liittyvi√§ ominaisuuksia, unitutkimus hy√∂dynt√§√§ enenev√§sti kvantitatiivisia analyysimenetelmi√§. Lapsilla unen paikalliset, kvantitatiiviset ominaisuudet riippuvat aivokuoren kypsymisest√§, jonka tiedet√§√§n etenev√§n taka-alueilta kohti etuosia i√§n my√∂t√§. Lis√§ksi unen paikallisiin ominaisuuksiin vaikuttavat edelt√§v√§n valveen kesto, kullekin aivokuoren alueelle valveen aikana kohdistunut kuormitus sek√§ sirkadiaanisen rytmin vaihe. Lis√§ksi tiedet√§√§n, ett√§ unen kvantitatiiviset ominaisuudet assosioituvat aikuisilla √§lykkyyteen ja lapsilla psykomotorisen kehityksen osa-alueisiin. Ymm√§rrys vauvojen unen kvantitatiivisista piirteist√§ on kuitenkin toistaiseksi melko hajanaista, sill√§ tutkimuksia vauvaik√§isill√§ on v√§h√§n, menetelm√§t ja ik√§ryhm√§t ovat olleet vaihtelevia ja tutkimuksista on tyypillisesti puuttunut joko topografinen tai ajallinen, koko unijakson kattava ulottuvuus. T√§ss√§ v√§it√∂skirjassa tarkastellaan vauvaik√§isten PSG-tutkimusten vertailtavuuden ongelmia. T√§m√§ tutkimus korostaa, ett√§ kirjallisuudessa esitettyjen unisuureiden taustalla olevat menetelm√§t on otettava huomioon, kun niit√§ k√§ytet√§√§n kliinisess√§ ty√∂ss√§. Vertailtavuuden tulevaisuus n√§ytt√§√§ kuitenkin valoisammalta, sill√§ vastasyntyneillekin on hiljattain saatu standardoidut uniluokittelus√§√§nn√∂t ja lis√§ksi teknologian kehitys on k√§yt√§nn√∂ss√§ poistanut esimerkiksi rekister√∂intien kestoon ja kanavavalikoimaan liittyv√§t tekniset rajoitteet viime vuosikymmenin√§. On todenn√§k√∂ist√§, ett√§ yhten√§iset s√§√§nn√∂t ja vakioidut menetelm√§t parantavat eri tutkimusten vertailtavuutta. T√§m√§ tutkimus lis√§√§ tietoa unen topografisista ja ik√§riippuvaisista kvantitatiivisista ominaisuuksista vauvoilla. Monet todetuista unen paikallisista eroista liittyv√§t todenn√§k√∂isesti aivojen ik√§riippuvaiseen, alueelliseen kypsymiseen ja p√§√§piirteilt√§√§n ne ovat aiempien tutkimusten tuloksiin verrattavia. Kuitenkin lis√§ksi t√§ss√§ tutkimuksessa sek√§ yhden ett√§ kahdeksan kuukauden ik√§isill√§ havaittiin unen kvantitatiivisissa ominaisuuksissa my√∂s hemisf√§√§rienv√§lisi√§ eroja, jollaisia on vain harvoin raportoitu aiemmissa tutkimuksissa. T√§m√§n tutkimuksen perusteella hemisf√§√§rierojen fysiologista merkityst√§ voi vain spekuloida aivojen funktionaalisen anatomian perusteella. Havaitut paikalliset erot lis√§√§v√§t kuitenkin tietoa unen kehityksest√§ ja erityisen merkityksellisi√§ ne ovat tulevien tutkimusasetelmien suunnittelun kannalta. Lis√§ksi tutkittiin unen kvantitatiivisten parametrien ja psykomotorisen kehityksen assosiaatioita kahdeksan kuukauden ik√§isill√§. Assosiaatioita ei ollut aiemmin tutkittu n√§in nuorilla vauvoilla. Vaikka t√§ss√§ tutkimuksessa todettujen assosiaatioiden fysiologinen merkitys vaatiikin lis√§tutkimusta toisenlaisin tutkimusasetelmin, t√§m√§ ty√∂ korostaa analysoitavien taajuuskaistojen ja menetelmien valinnan t√§rkeytt√§ ‚Äď erityisesti tutkittavien ik√§ on ehdottomasti otettava huomioon.In infancy, sleep reflects the development of the central nervous system (CNS). Accordingly, the quality and quantity of sleep are known to be consequential for the future development and well-being of infants. In addition to uncovering the basic physiology of sleep, the objective of infant sleep research is to advance knowledge of the typical development of sleep and to facilitate the early recognition of abnormality. Ultimately, the increasing knowledge can be used to refine timely and proportionate interventions. The infant sleep literature is infamous for the variability of the sleep parameters published. In the recent decades, the vast majority of sleep research has been based on polysomnography (PSG), which is considered the gold standard of sleep studies. PSG is a multi-channeled continuous recording during sleep that comprises EEG and auxiliary channels for the sleep stage differentiation, and a set of further physiologic signals that measure, for example, the respiratory function. Traditionally, the differentiation or scoring of the sleep stages is performed visually according to specific visual scoring rules, and it is likely that the considerable diversity of the sleep scoring rules and methods promote variability in the reported values. Regarding the inter-individual differences, the rapid development of the CNS and the age- dependent transformation of sleep it entails surely augment the diversity still further. Because of the large variability, the conventional sleep architecture cannot be used to detect abnormality apart from in extreme cases. Furthermore, the basic analysis of sleep architecture lacks the topographical and frequency domain resolutions. In order to uncover the topographical nuances in the sleep features, contemporary sleep research employs quantitative methods of sleep analysis. Indeed, sleep is not homogenous across the convexity. Instead, the quantitative features of sleep EEG are modulated by the local and global regulations of sleep. The regulatory processes depend on the duration of wakefulness, the time of the day, and the amount of stress a cortical area has endured during wakefulness. Importantly, in children, the topographical properties of the sleep EEG activity depend on the topical stage of cortical maturation, which is known to progress from the posterior areas towards the anterior with age. Furthermore, the quantitative EEG features are known to associate with intelligence in adults, and with the various domains of psychomotor development in children. However, the younger the children, the less the local features of sleep have been studied. In infants, the knowledge of the computational characteristics of sleep and their associations with the psychomotor development is particularly scarce. This dissertation focuses on the issues of comparability in the young infants¬ī conventional PSG studies. The present work highlights the importance of scrutinizing the methodology underlying the values presented in the infant sleep literature. Intuitively, the use of uniform sleep scoring rules and standardized methodology will help to improve comparability among sleep studies. Recently, the standardized scoring criteria for young infants became available, and in the past few decades, the technical obstacles delimiting the choice of the recorded PSG channels have been overcome. Consequently, the future of comparability looks brighter. Furthermore, the findings of this dissertation add to the body of knowledge of computational, local, and age dependent sleep quality in infancy. Many of the findings were attributable to age-dependent brain maturation in agreement with the findings of previous studies. However, the infants tended to present inter- hemispheric differences in their sleep parameters, an observation which has been rarely reported in the past. For the moment, the physiological significance of these findings can only be speculated, based on general knowledge of functional brain anatomy, but they contribute to a more solid view of developing sleep, and will surely help in the design of future studies. In addition, in the present work, the associations of the computational sleep parameters with the eight-month-old infants¬ī psychomotor development were studied. The associations have not been studied in infants this young before, and while the fundamental origins of the associations found warrant further research, the present work stresses the careful consideration of the studied frequency ranges, the topography of the analyses, and the timing and duration of the sleep recordings
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