Разработка инвестиционного проекта «Пасека» в развитии агротуризма

Материалы V Междунар. науч. конф. студентов, аспирантов и молодых ученых, Гомель, 24 мая 2012

Neuropsychological Function in Relation to Structural and Functional Brain Changes in Alzheimer’s Disease

The aim of this doctoral thesis was to study neuropsychological function in relation to structural and functional brain changes in Alzheimer´s disease (AD). In the first study relations between hippocampal volume, neuropsychological function and limbic-hypothalamic-pituitary-adrenal (LHPA) axis disturbances in AD were investigated with magnetic resonance imaging (MRI). Reduced hippocampal CA1 volume and suppressed cortisol levels in combination, best predicted the variation in neuropsychological performance. The conclusion was that reduced hippocampal volume and LHPA axis disturbances are associated to level of cognitive function in AD. The second study focused on whether patients with early AD showed an altered regional cerebral blood flow (rCBF) pattern compared to control persons, correlation between performance on memory tests and rCBF in sub-lobar volumes of the brain were investigated. The rCBF was measured with single photon emission computed tomography (SPECT). AD-patients showed a significantly lower rCBF in temporoparietal regions including left hippocampus compared to controls. The diagnostic sensitivity and specificity for AD was high in temporoparietal regions. AD-patients had significantly lower performance on semantic and, in particular, episodic memory-tests compared to the controls, and their performance on several episodic tests correlated with rCBF in parietal and temporal regions including left hippocampus, which suggest that abnormalities in the rCBF pattern underlie impaired episodic memory functioning in AD. The conclusion was that an observer-independent analyzing method for SPECT with sub-lobar volumes VOI´s is promising in the diagnosis of AD. In a third study possible differences in memory-related functional brain activation between persons with high versus low risk for AD were examined with functional magnetic resonance imaging (fMRI). The high-risk individuals performed worse than low-risk individuals on tests of episodic memory. Patterns of brain activity during episodic encoding and retrieval showed significant group differences. During both encoding and retrieval, the low-risk persons showed increased activity relative to a baseline condition in prefrontal and hippocampal brain regions that previously have been implicated in episodic memory. By contrast, the high-risk persons did not significantly activate any prefrontal regions, but instead showed increased activity in visual occipito-temporal regions. The conclusion was that patterns of prefrontal brain activity related to episodic memory differed between persons with high versus low risk for AD, and lowered prefrontal activity may predict subsequent disease. In a final study SPECT was used to map patterns of rCBF in an activated state (an episodic encoding task) and in a rest condition in persons with mild AD and in healthy elderly control persons. A reduction of rCBF in temporoparietal regions that was more pronounced in mild AD in the activated encoding task was observed. The conclusion was that there are rCBF differences between mild AD patients and healthy controls in temporoparietal regions, and the temporoparietal reduction is more pronounced during activation than during rest which might be important in the early diagnosis of AD. Taken together, these findings show that level of neuropsychological function, notably episodic memory, can be systematically related to functional disturbances in the LHPA axis and to the function of temporoparietal and prefrontal brain regions in AD patients. These changes are detectable in patients with risk for AD and in an early phase of AD which suggests that the obtained results might be important for early diagnosis of AD

Dynamic Trajectory of Long-Term Cognitive Improvement Up to 10 Years in Young Community-Dwelling Stroke Survivors : A Cohort Study

Background and objective: The trajectories of long-term and domain-specific cognitive alterations over a decade after stroke are largely unknown. This study aims to investigate the dynamic alterations of domain-specific cognitive performance among young stroke survivors over 10 years after their first stroke. Methods: A prospective cohort study was carried out on 38 young stroke survivors (aged 18-65 at stroke onset) living in the community at 10 years after their first stroke. The cognitive outcomes were assessed repeatedly at 1 week, 7 months, and 10 years after their first stroke on the sub-domains: process speed (Symbol search and Coding from WAIS, TMT-A), visual attention (Bells test), visuospatial function (Block design from WAIS, RCFT), executive function (TMT-B, verbal fluency), verbal function [Letter fluency (FAS) from D-KEFS and CD], working memory (Digit Span from WAIS), immediate memory (RCFT and CD), and delayed memory (RCFT and CD). Global cognition was evaluated with Mini mental state examination at the two later time-points. Results: We found a delayed significant improvement of working memory with total recovery 10 years after participants' stroke. Visuospatial function recovered already at 7 months and remained stable at 10-year follow-up. Process speed demonstrated a significant decrease at 10 years compared to 7 months after stroke onset, a decrease which could be compensated by enhancements of other cognitive domains. No further deterioration was found in verbal function, immediate-, and delayed memory, and executive function during 10-year follow-up. Global cognition improved by on average two points between 7 months and 10 years. Education level and fatigue showed low to moderate positive correlations with cognitive improvements. Conclusions: The concordance of cognitive improvements between domain-specific and global cognitions strongly suggest that some young stroke survivors do improve their cognitive outcome over a 10-year period following their first stroke. This finding fills a gap of knowledge with respect to the dynamic trajectory of post-stroke cognition, with important implications in clinical practice

Subjective and Objective Assessments of Executive Functioning among Persons 10 years after Stroke Onset

Aim: This study aimed to investigate executive functioning (EF) among patients 10 years after stroke onset through comparing subjective patients’ and informants’ perceptions as well as objective neuropsychological assessments (NPAs). Materials and Method: One month prior to the neuropsychological assessment, 36 patients and their informants completed the Behaviour Rating Inventory of Executive Function - Adult Version (Brief-A) around 10 years after stroke onset. The patients’ EF was assessed with verbal fluency (FAS), backward Digit span backward and Trail making test (TMT)-B.  Results: We found no significant differences between patient and informant ratings on EF on a group level, but more patients reported clinically significant executive dysfunctions (T > 65) than their informants. Only poor to slight agreements were observed between the patient and informant ratings of the BRIEF-A.  Digit span backward was the only executive test that demonstrated significant improvement of EF 10 years post-stroke in the cohort. Neither patient nor informant ratings on EF showed any significant association with objective EF test performance. Conclusions: Mismatch patient-informant agreement on perceived executive dysfunction showed no clear association with EF test performance in this study. This may indicate the complexity of EF among persons with stroke at chronic phase.

Visuospatial Function at Sub-Acute Phase Predicts Fatigue 10 Years After Stroke

Background and Objective: Fatigue is common among stroke survivors; and has significant negative consequences. However, long-term follow-up on post-stroke fatigue and it's association with cognitive and physiological parameters remains vague. Methods: A prospective cohort study was carried out on 38 young stroke survivors (aged 18–65 at stroke onset) living in the community 10 years after first-ever stroke. Fatigue was assessed by Fatigue assessment scale (FAS). Global cognition and cognitive sub-domains were assessed repeatedly at 1 week, 7 months, and 10 years after their first-ever stroke. Univariate correlation analysis was used to investigate associations and multivariate regression was used to investigate predictors and association with fatigue. Results: At 10-years follow-up after stroke onset, more than half of the 38 participants suffered from fatigue [with median score 25 on FAS with 25–75% percentile (21–28)]. Most of them were independent in their everyday life [mRS median score 1 (0–2)]. In univariate correlation analyses, higher fatigue score was significantly correlated to higher independence in the daily activity, higher BMI, anxiety, higher scores on global cognition and better working memory at 10-years follow-up as well as better visuospatial functions after 7 months and 10-years. In a multiple regression analysis, only visuospatial function at 7-months follow-up was a significant predictor of fatigue 10 years after stroke onset [F = 23.07, p < 0.009], with adjusted (R2 = 0.815) i.e., higher scores on Block design were associated with more fatigue. Conclusion: Our results extended the time course of post-stroke fatigue up to 10 years after stroke onset. The participants with more fatigue performed better in cognitive assessments and daily activity, which indicated dissociation between fatigue and fatigability among stroke patients. Visuospatial function at the sub-acute phase predicted independently late post-stroke fatigue. This may offer a broad time window for rehabilitation and information about fatigue. The clinical implications of the current findings are worth to be studied further

Premorbid employment and education predicts improvement in general cognition ten years after stroke onset : a longitudinal cohort study

Background: We have recently demonstrated significant general cognitive recovery with delayed improvement of working memory 10 years after stroke in a unique longitudinal cohort.Aim: This study investigated demographic and clinical characteristics relevant to improved cognitive functions 10-year after a first-ever stroke.    Materials and Methods: A prospective longitudinal cohort study was carried out in 38 middle-aged (mean age =54 at stroke onset) stroke survivors. Cognition was assessed thrice at one week, seven months, and ten years after the stroke. Working memory and visuospatial function were assessed with the Digit Span and Block Design subtests, respectively. General cognition was evaluated with the Mini-Mental State Examination at the two later time points. Multivariate linear regression was used to identify the variables that may significantly predict improved cognitive functions at 10-year follow-up. Results: We found that having a full-time job prior to the stroke, suffering an ischemic (as opposed to a hemorrhagic) stroke, and having a university education predicted significantly superior general cognitive function 10 years after stroke (R2 of 0.77, p <0.001), while working memory and visuospatial function at 1 week after stroke significantly predicted their respective functions at 10-year follow-up (R2 of 0.41, p = 0.003).  Conclusions: Our results indicate that premorbid employment status and higher education as well as having suffered from an ischemic rather than a hemorrhagic stroke might predict superior cognitive recovery among middle-aged individuals 10 years after stroke.

Improvement of cognition across a decade after stroke correlates with the integrity of functional brain networks

Background and objective: We recently reported improvements of working memory across 10 years post stroke among middle-aged individuals. However, the mechanisms underlying working-memory recovery are largely unknown. This study investigated the associations between long-term improvement of working memory and resting-state functional connectivity in two frontoparietal networks: the frontoparietal network and the dorsal attention network. Methods: Working memory was repeatedly assessed by the Digit Span Backwards task in 21 persons, within 1 year after stroke onset and again 10 years post stroke onset. Brain functional connectivity was examined by resting state functional magnetic resonance imaging at the 10-year follow-up. Results: A significant improvement of working memory was found among 21 persons after stroke (median age = 64) at the 10-year follow-up compared to the within-one-year assessment. The magnitude of performance improvement on the Digit Span Backwards task was significantly positively correlated with stronger brain connectivity in the frontoparietal network (r = 0.51, p = 0.018) measured at the 10-year follow-up only. A similar association was observed in the dorsal attention network (r = 0.43, p = 0.052) but not in a visual network (r = -0.17, p = 0.46) that served as a control network. The association between functional connectivity within the above-mentioned networks and Digit Span Backwards scores at 10-year after stroke was in the same direction but did not reach significance. Conclusions: The present work relate stronger long-term performance improvement on the Digit Span Backwards task with higher integrity of frontoparietal network connectivity

Chlamydia trachomatis and Anti-MUC1 Serology and Subsequent Risk of High-Grade Serous Ovarian Cancer : A Population-Based Case-Control Study in Northern Sweden

BACKGROUND: Chlamydia trachomatis salpingitis causes inflammatory damage to the fallopian tube and could potentially cause initiation and progression of high-grade serous ovarian cancer (HGSC). Furthermore, C. trachomatis infection may stimulate mucin 1 (MUC1) protein production, possibly affecting anti-MUC1 antibody levels. The aim of this study was to examine if serology indicating past infection with C. trachomatis as well as anti-MUC1 production was associated with subsequent risk of HGSC. MATERIALS AND METHODS: In a prospective nested case-control study within the Northern Sweden Health and Disease Study and the Northern Sweden Maternity Cohort, the prevalence of chlamydial and anti-MUC1 antibodies was analyzed in blood samples drawn more than one year before diagnosis from 92 women with HGSC and 359 matched controls. Matching factors were age, date at blood draw, and sampling cohort. Plasma C. trachomatis IgG was analyzed using commercial micro-immunofluorescence test; chlamydial Heat Shock Protein 60 IgG (cHSP60) and anti-MUC1 IgG were analyzed with ELISA technique. RESULTS: The prevalence of C. trachomatis IgG and cHSP60 IgG antibodies, as well as the level of anti-MUC1 IgG was similar in women with HGSC and controls (16.3% vs. 17.0%, P = 0.87; 27.2% vs. 28.5%, P = 0.80; median 0.24 vs. 0.25, P = 0.70). Anti-MUC1 IgG and cHSP60 IgG levels were correlated (r = 0.169; P < 0.001). CONCLUSIONS: The findings of this prospective nested case-control study did not support an association between C. trachomatis infection, as measured by chlamydial serology, or anti-MUC1 IgG antibodies, and subsequent risk of HGSC