Cognitive Functions After Traumatic Brain Injury. A 30-year Follow-up Study

Many cognitive deficits after TBI (traumatic brain injury) are well known, such as memory and concentration problems, as well as reduced information-processing speed. What happens to patients and cognitive functioning after immediate recovery is poorly known. Cognitive functioning is flexible and may be influenced by genetic, psychological and environmental factors decades after TBI. The general aim of this thesis was to describe the long-term cognitive course after TBI, to find variables that may contribute to it, and how the cognitive functions after TBI are associated with specific medical factors and reduced survival. The original study group consisted of 192 patients with TBI who were originally assessed with the Mild Deterioration Battery (MDB) on average two years after the injury, during the years 1966 – 1972. During a 30-year follow-up, we studied the risks for reduced survival, and the mortality of the patients was compared with the general population using the Standardized Mortality Ratio (SMR). Sixty-one patients were re-assessed during 1998-2000. These patients were evaluated with the MDB, computerized testing, and with various other neuropsychological methods for attention and executive functions. Apolipoprotein-E (ApoE) genotyping and magnetic resonance imaging (MRI) based on volumetric analysis of the hippocampus and lateral ventricles were performed. Depressive symptoms were evaluated with the short form of the Beck depression inventory. The cognitive performance at follow-up was compared with a control group that was similar to the study group in regard to age and education. The cognitive outcome of the patients with TBI varied after three decades. The majority of the patients showed a decline in their cognitive level, the rest either improved or stayed at the same level. Male gender and higher age at injury were significant risk factors for the decline. Whereas most cognitive domains declined during the follow-up, semantic memory behaved in the opposite way, showing recovery after TBI. In the follow-up assessment, the memory decline and impairments in the set-shifting domain of executive functions were associated with MRI-volumetric measures, whereas reduction in information-processing speed was not associated with the MRI measures. The presence of local contusions was only weakly associated with cognitive functions. Only few cognitive methods for attention were capable of discriminating TBI patients with and without depressive symptoms. On the other hand, most complex attentional tests were sensitive enough to discriminate TBI patients (non-depressive) from controls. This means that complex attention functions, mediated by the frontal lobes, are relatively independent of depressive symptoms post-TBI. The presence of ApoE4 was associated with different kinds of memory processes including verbal and visual episodic memory, semantic memory and verbal working memory, depending on the length of time since TBI. Many other cognitive processes were not affected by the presence of ApoE4. Age at injury and poor vocational outcome were independent risk factors for reduced survival in the multivariate analysis. Late mortality was higher among younger subjects (age < 40 years at death) compared with the general population which should be borne in mind when assessing the need for rehabilitation services and long-term follow-up after TBI.Siirretty Doriast

The Library as a Part of Research Development Work

One of the main conclusions of the Research Assessment Exercise (RAE) conducted at Tampere University of Technology (TUT) in 2011 was the need to develop TUT’s publication activities and patterns. It was pointed out by the assessment panels that the researchers’ choice of publication channels was not always successful. Also in the case of many departments the amount of publications was unsatisfactory. In order to address the challenges pointed out by the RAE, a Roadmap for Research was created and it includes measures to improve TUT’s publication activity. At the same time, the importance of publications in the national allocation of research funding has grown. TUT Library has been in a key role in the management of publication activities since the beginning of the 1990’s. At the moment, the library is managing the procurement of a new current research information system (CRIS). The CRIS will increase the visibility of TUT’s academic activities by linking research outputs to projects and groups. The research outputs will be better presented in the context of research areas. Also in order to enhance the visibility and impact of TUT research outputs, the library is boosting open access publishing and encouraging research data management through national storage service. In order to support the development of TUT’s publication activities, the library created an information package called “Publication activities analyses”. The aim of the package is to give tools and support to the departments and researchers to develop their publishing activities and research skills related to promoting research outputs. Additionally, new web pages which are organized according to the life cycle of the research process presenting the library’s research support services were launched

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

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

Volatile emission from strawberry plants is induced by mite and leaf beetle feeding and methyl jasmonate

We have studied the emission of volatile organic compounds (VOCs) from young strawberry plants, cultivars Polka and Honeoye, after feeding by several strawberry herbivores under laboratory conditions. VOC profile of strawberry plants is highly dominated by green leaf volatiles (GLVs), which are released also due to mechanical damage. Our results reveal that strawberry has potential for inducible VOC defence, and this encourages testing the attractiveness of these strawberry VOCs to predatory mites

Nighttime melatonin secretion and sleep architecture: different associations in perimenopausal and postmenopausal women

Background: Sleep quality typically decreases after menopause, but the underlying mechanisms are poorly understood. Concentrations of melatonin are lower and its secretion profiles different before and after menopause. However, whether and how melatonin and sleep architecture are associated in women of different reproductive states have not been examined to date. Methods: Overnight serum melatonin samples were taken from 17 perimenopausal and 18 postmenopausal healthy women. Sleep quality was measured with all-night polysomnography recordings. Results: Melatonin concentrations tended to be the lowest during NREM sleep, and were associated with higher odds of transitions from wake to NREM sleep. The curves of predicted overnight melatonin values from linear mixed models varied according to sleep phases (NREM, REM, Wake) in perimenopausal, but not in postmenopausal women. In perimenopause higher melatonin area under curve (AUC) correlated with higher slow-wave activity (p = 0.043), and higher minimum concentrations with shorter slow-wave sleep (SWS) latency (p = 0.029). In postmenopause higher mean and maximum melatonin concentrations and AUC correlated with lower SWS percentage (p = 0.044, p = 0.029, p = 0.032), and higher mean (p = 0.032), maximum (p = 0.032) and minimum (p = 0.037) concentrations with more awakenings from REM sleep. In the age- and BMI-adjusted regression models, the association between higher maximum (p = 0.046) melatonin concentration and lower SWS percentage remained. Conclusions: The relationship between melatonin and sleep architecture differed in perimenopausal and postmenopausal women. After menopause, high melatonin concentrations were associated with worse sleep. Whether these different patterns are related to aging of the reproductive system, and to decrease in menopausal sleep quality, remains to be elucidated. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

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

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

CPAP Treatment Partly Normalizes Sleep Spindle Features in Obstructive Sleep Apnea

Objective. Obstructive sleep apnea (OSA) decreases sleep spindle density and frequency. We evaluated the effects of continuous positive airway pressure (CPAP) treatment on different features of sleep spindles. Methods. Twenty OSA patients underwent two night polysomnographies in a diagnostic phase and one night polysomnography after 6 months of CPAP treatment. The control group comprised 20 healthy controls. Sleep spindles were analyzed by a previously developed automated method. Unilateral and bilateral spindles were identified in central and frontopolar brain locations. Spindle density and frequency were determined for the first and last half of the NREM time. Results. The density of bilateral central spindles, which did not change in the untreated OSA patients, increased towards the morning hours during CPAP treatment and in the controls. Central spindles did not become faster with sleep in OSA patients and the central spindles remained slow in the left hemisphere even with CPAP. Conclusion. CPAP treatment normalized spindle features only partially. The changes may be associated with deficits in thalamocortical spindle generating loops. Significance. This study shows that some sleep spindle changes persist after CPAP treatment in OSA patients. The association of these changes to daytime symptoms in OSA patients needs to be further evaluated

Cognitive functions and symptoms predicting later use of psychiatric services following mild traumatic brain injury in school-age

Objective To investigate whether neuropsychological test performance or presence of some specific injury symptoms at 1-3 months following pediatric mild traumatic brain injury (mTBI) can help to identify the children at risk for developing post-traumatic psychiatric symptoms. Methods Data from 120 children and adolescents aged 7-15 years, treated at Turku University Hospital between 2010 and 2016 due to mTBI, and who had undergone neuropsychological evaluation at 1-3 months following injury, were enrolled from the hospital records. Neuropsychological test performancesand injury symptom reports were retrospectively retrieved from the patient files. Results Slow information processing speed (p = 0.044), emotion regulation deficit (p = 0.014), impulsivity (p = 0.013), verbal processing difficulties (p = 0.042) and headache (p = 0.026) were independent predictors for having later contact in psychiatric care. Conclusions Neuropsychological examination containing measure of information processing speed, injury symptom interview, and parental questionnaires on behavioural issues of the child at 1-3 months following mTBI seems to be useful in detecting children with risk for post traumatic psychiatric symptoms. Targeted support and guidance for this group of children and adolescents and their families are recommended to prevent the development of an unfavorable psychosocial outcome.Peer reviewe

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

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