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- Bergman, Lina, 1982-
(författare)
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Cerebral biomarkers in women with preeclampsia
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Preeclampsia and eclampsia are among the most common causes of maternal and fetal mortality and morbidity worldwide. There are no reliable means to predict eclampsia or cerebral edema in women with preeclampsia and knowledge of the brain involvement in preeclampsia is still limited. S100B and neuron specific enolase (NSE) are two cerebral biomarkers of glial- and neuronal origin respectively. They are used as predictors for neurological outcome after traumatic brain injuries and cardiac arrest but have not yet been investigated in preeclampsia.This thesis is based on one longitudinal cohort study of pregnant women (n=469, Paper I and III), one cross sectional study of women with preeclampsia and women with normal pregnancies (n=53 and 58 respectively, Paper II and IV) and one experimental animal study of eclampsia (Paper V).In Paper I and III, plasma concentrations of S100B and NSE were investigated throughout pregnancy in women developing preeclampsia (n=16) and in women with normal pregnancies (n=36) in a nested case control study. Plasma concentrations were increased in women developing preeclampsia in gestational week 33 and 37 for S100B and in gestational week 37 for NSE compared to women with normal pregnancies.In Paper II and IV, increased plasma concentrations of S100B and NSE were confirmed among women with preeclampsia compared to women with normal pregnancies. Furthermore, increased plasma concentrations of S100B correlated to visual disturbances among women with preeclampsia (Paper II) and plasma concentrations of S100B and NSE remained increased among women with preeclampsia one year after delivery (Paper IV).In Paper V, an experimental rat model of preeclampsia and eclampsia demonstrated increased serum concentrations of S100B after seizures in normal pregnancy (n=5) and a tendency towards increased plasma concentrations of S100B in preeclampsia (n=5) compared to normal pregnancy (n=5) without seizures. Furthermore, after seizures, animals with magnesium sulphate treatment demonstrated increased serum concentrations of S100B and NSE compared to no treatment.In conclusion; plasma concentrations of S100B and NSE are increased in preeclampsia during late pregnancy and postpartum and S100B correlates to visual disturbances in women with preeclampsia. The findings are partly confirmed in an animal model of eclampsia.
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- Correia de Verdier, Maria, 1983-
(författare)
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Evaluation of Intracranial Arteriovenous Malformations with Magnetic Resonance Imaging
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Intracranial arteriovenous malformations (AVMs) are characterized by feeding arteries, a tangle of abnormal vessels (nidus) and draining veins. Radiological evaluation methods are used in diagnosing AVMs, treatment planning, post-treatment evaluation and monitoring stability. The general aim of our studies reviewed in this thesis was to develop and evaluate magnetic resonance imaging (MRI) techniques for the evaluation of AVMs. MethodsPaper I – In 30 patients treated with proton radiation therapy, radiation-induced MRI changes (vasogenic edema, contrast enhancement and cavitation) and their association with development of neurological symptoms and nidus obliteration were assessed. Paper II – We evaluated the effect of acquisition parameters (voxel size, number of signal averages and velocity encoding) on the accuracy and precision of phase-contrast MRI (PC-MRI)-measured flow and velocity in a small-lumen vessel phantom with constant flow. Paper III – Normal ranges and test-retest reproducibility of flow and velocity in the anterior, middle and posterior cerebral arteries were measured with PC-MRI in 30 healthy volunteers.Paper IV – We studied PC-MRI-measured flow and velocity in feeding arteries in 10 patients with AVMs and compared the values obtained with the results from paper III. We also assessed post-treatment changes in flow and velocity in three patients. Results Paper I – Radiation-induced MRI changes were found in 87% of patients after proton radiation treatment of AVMs. MRI changes were associated with neurological symptoms but not with nidus obliteration. Paper II – PC-MRI overestimated flow in a small-lumen vessel phantom. Accuracy for flow measurements improved by decreasing voxel size. Precision for both flow and velocity measurements improved by increasing voxel size. Precision for flow measurements improved by increasing the number of signal averages.Paper III – We reported normal ranges and test-retest reproducibility for PC-MRI-measured flow and velocity in the main intracranial arteries. Reproducibility was overall quite low, but higher for the middle cerebral arteries than for the anterior and posterior cerebral arteries.Paper IV – Patients with a large nidus have increased velocity measured with PC-MRI in feeding arteries compared to intracranial arteries in healthy individuals. There is a reduction in PC-MRI-measured flow and velocity after treatment. ConclusionRadiation-induced MRI changes are common after proton radiation treatment of AVMs. The accuracy and precision of PC-MRI measurements in a phantom depend on acquisition parameter settings. In patients with AVMs with a large nidus, increased velocity is observed in feeding arteries, and a decrease in flow and velocity is observed after treatment. PC-MRI can potentially be used as a clinical tool to aid treatment planning and post-treatment evaluation.
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- Nelander, Maria, 1974-
(författare)
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Preeclampsia and the Brain : Epidemiological and Magnetic Resonance Studies
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Preeclampsia is a pregnancy specific syndrome that causes substantial maternal and fetal morbidity and mortality. One major contributor to maternal deaths is eclampsia, i.e. when seizures arise in the context of preeclampsia. The pathophysiology of eclampsia is still incompletely chartered and the long-term cerebral consequences of preeclampsia are also largely unknown.This thesis consists of a register based cohort study (n=3232, study I), and a cross-sectional neuroimaging study of pregnant women with and without preeclampsia (n=78, studies II-IV).In paper I, we compared the incidence of dementia and cardiovascular disease (CVD) between women ≥65 years with a self-reported history of hypertensive pregnancy, and women with a normotensive pregnancy. No difference was found regarding dementia, but an increased risk of CVD persisted among these elderly women.In paper II, we used phosphorus magnetic resonance spectroscopy to measure cerebral magnesium levels (Mg2+). We found lower levels of Mg2+ in women with preeclampsia than in women with normal pregnancy and non-pregnant women. Further, which was novel, we showed that lower cerebral Mg2+levels correlated with visual disturbances. The findings are interesting, since magnesium sulfate is the most effective treatment and prophylaxis for eclampsia, but with a largely unknown mechanism of action.In paper III, we measured cerebral organic osmolytes with proton magnetic resonance spectroscopy and found lower levels of osmolytes in pregnancy. Cerebral osmolytes were positively correlated with a decreased plasma osmolality, indicating that there is a joint biological mechanism. The only osmolyte that differed between women with preeclampsia and healthy pregnant women was glutamate. Glutamate is an excitatory neurotransmitter, which also functions as an osmolyte. Thus, lower cerebral glutamate levels could have implications on the pathophysiology of seizures.In paper IV, cerebral perfusion and edema were assessed with magnetic resonance imaging using intravoxel incoherent motion technique. A reduced perfusion fraction was found in a part of the basal ganglia in women with preeclampsia. No difference in edema was detected.Our findings indicate Mg2+ metabolism, plasma hypoosmolality and possibly cerebral hypoperfusion to be involved in the pathophysiology of cerebral affection in preeclampsia.
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- Thorgeirsdottir, Lilja, et al.
(författare)
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Study protocol: establishment of a multicentre pre-eclampsia database and biobank in Sweden: GO PROVE and UP MOST, a prospective cohort study
- 2021
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Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 11:11
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Introduction Pre-eclampsia, a multisystem disorder in pregnancy, is one of the most common causes of maternal morbidity and mortality worldwide. However, we lack methods for objective assessment of organ function in pre-eclampsia and predictors of organ impairment during and after pre-eclampsia. The women’s and their partners’ experiences of pre-eclampsia have not been studied in detail. To phenotype different subtypes of the disorder is of importance for prediction, prevention, surveillance, treatment and follow-up of pre-eclampsia.The aim of this study is to set up a multicentre database and biobank for pre-eclampsia in order to contribute to a safer and more individualised treatment and care.Methods and analysis This is a multicentre cohort study. Prospectively recruited pregnant women ≥18 years, diagnosed with pre-eclampsia presenting at Sahlgrenska University Hospital, Uppsala University Hospital and at Södra Älvsborgs Hospital, Sweden, as well as normotensive controls are eligible for participation. At inclusion and at 1-year follow-up, the participants donate biosamples that are stored in a biobank and they are also asked to participate in various organ-specific evaluations. In addition, questionnaires and interviews regarding the women’s and partner’s experiences are distributed at follow-up.Ethics and dissemination By creating a database and biobank, we will provide the means to explore the disorder in a broader sense and allow clinical and laboratory discoveries that can be translated to clinical trials aiming at improved care of women with pre-eclampsia. Further, to evaluate experiences and the psychological impact of being affected by pre-eclampsia can improve the care of pregnant women and their partners. In case of incidental pathological findings during examinations performed, they will be handled in accordance with clinical routine. Data are stored in a secure online database. Biobank samples are identified through the women’s personal identification number and pseudonymised after identification in the biobank before analysis.This study was approved by the regional ethical review board in Gothenburg on 28 December 2018 (approval number 955-18) and by the Swedish Ethical Review Authority on 27 February 2019 (approval number 2019-00309).
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- Abu Hamdeh, Sami, et al.
(författare)
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Intracranial pressure elevations in diffuse axonal injury are associated with non-hemorrhagic MR lesions in central mesencephalic structures
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Objective: Increased intracranial pressure (ICP) in severe traumatic brain injury (TBI) patients with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in DAI patients.Methods: Fifty-two severe TBI patients (median 24, range 9-61 years), with ICP-monitoring and DAI on MRI, using T2*-weighted gradient echo, susceptibility-weighted and diffusion-weighted (DW) sequences, were enrolled. Proportion of good monitoring time (GMT) with ICP>20 mmHg during the first 120 hours post-injury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression. Results: All patients had episodes of ICP>20 mmHg. The mean proportion of GMT with ICP>20 mmHg was 5% and 27% of the patients (14/52) had more than 5% of GMT with ICP>20 mmHg. Glasgow Coma Scale motor score at admission (P=0.04) and lesions on DW images in the substantia nigra and mesencephalic tegmentum (SN-T, P=0.001) were associated with the proportion of GMT with ICP>20 mmHg. In multivariate linear regression, lesions on DW images in SN-T (8% of GMT with ICP>20 mmHg, 95% CI 3–13%, P=0.004) and young age (-0.2% of GMT with ICP>20 mmHg, 95% CI -0.07–-0.3%, P=0.0008) were associated with increased ICP. Conclusions: Increased ICP occurs in ~1/3 of severe TBI patients with DAI. Age and lesions on DW images in the central mesencephalon (SN-T) associate with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in DAI patients.
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