Browsing by Subject "ISCHEMIC-STROKE"

Sort by: Order: Results:

Now showing items 21-28 of 28
  • Anttila, Jenni E.; Pöyhönen, Suvi; Airavaara, Mikko (2019)
    A stroke affecting the somatosensory pathway can trigger central post-stroke pain syndrome (CPSP). The symptoms often include hyperalgesia, which has also been described in rodents after the direct damage of the thalamus. Previous studies have shown that hemorrhagic stroke or ischemia caused by vasoconstriction in the thalamus induces increased pain sensitivity. We investigated whether inducing secondary damage in the thalamus by a cortical stroke causes similar pain hypersensitivity as has previously been reported with direct ischemic injury. We induced a focal cortical ischemia-reperfusion injury in male rats, quantified the amount of secondary neurodegeneration in the thalamus, and measured whether the thalamic neurodegeneration is associated with thermal or mechanical hypersensitivity. After one month, we observed extensive neuronal degeneration and found approximately 40% decrease in the number of NeuN+ cells in the ipsilateral thalamus. At the same time, there was a massive accumulation-a 30-fold increase-of phagocytic cells in the ipsilateral thalamus. However, despite the evident damage in the thalamus, we did not observe thermal or mechanical sensitization. Thus, thalamic neurodegeneration after cortical ischemia-reperfusion does not induce CPSP-like symptoms in rats, and these results suggest that direct ischemic damage is needed for CPSP induction. Despite not observing hyperalgesia, we investigated whether administration of cerebral dopamine neurotrophic factor (CDNF) and mesencephalic astrocyte-derived neurotrophic factor (MANF) into the ipsilateral thalamus would reduce the secondary damage. We gave a single injection (10 mu g) of recombinant CDNF or MANF protein into the thalamus at 7 days post-stroke. Both CDNF and MANF treatment promoted the functional recovery but had no effect on the neuronal loss or the amount of phagocytic cells in the thalamus.
  • Abdul-Rahim, Azmil H.; VISTA Collaborators; Kaste, M. (2019)
    BackgroundInter-observer variability in stroke aetiological classification may have an effect on trial power and estimation of treatment effect. We modelled the effect of misclassification on required sample size in a hypothetical cardioembolic (CE) stroke trial.MethodsWe performed a systematic review to quantify the reliability (inter-observer variability) of various stroke aetiological classification systems. We then modelled the effect of this misclassification in a hypothetical trial of anticoagulant in CE stroke contaminated by patients with non-cardioembolic (non-CE) stroke aetiology. Rates of misclassification were based on the summary reliability estimates from our systematic review. We randomly sampled data from previous acute trials in CE and non-CE participants, using the Virtual International Stroke Trials Archive. We used bootstrapping to model the effect of varying misclassification rates on sample size required to detect a between-group treatment effect across 5000 permutations. We described outcomes in terms of survival and stroke recurrence censored at 90days.ResultsFrom 4655 titles, we found 14 articles describing three stroke classification systems. The inter-observer reliability of the classification systems varied from fair' to very good' and suggested misclassification rates of 5% and 20% for our modelling. The hypothetical trial, with 80% power and alpha 0.05, was able to show a difference in survival between anticoagulant and antiplatelet in CE with a sample size of 198 in both trial arms. Contamination of both arms with 5% misclassified participants inflated the required sample size to 237 and with 20% misclassification inflated the required sample size to 352, for equivalent trial power. For an outcome of stroke recurrence using the same data, base-case estimated sample size for 80% power and alpha 0.05 was n=502 in each arm, increasing to 605 at 5% contamination and 973 at 20% contamination.ConclusionsStroke aetiological classification systems suffer from inter-observer variability, and the resulting misclassification may limit trial power.Trial registrationProtocol available at reviewregistry540.
  • Putaala, Jukka; Nieminen, Tuomo (2018)
  • Leo, Vera; Sihvonen, Aleksi J.; Linnavalli, Tanja; Tervaniemi, Mari; Laine, Matti; Soinila, Seppo; Särkämö, Teppo (2018)
    Coupling novel verbal material with a musical melody can potentially aid in its learning and recall in healthy subjects, but this has never been systematically studied in stroke patients with cognitive deficits. In a counterbalanced design, we presented novel verbal material (short narrative stories) in both spoken and sung formats to stroke patients at the acute poststroke stage and 6 months poststroke. The task comprised three learning trials and a delayed recall trial. Memory performance on the spoken and sung tasks did not differ at the acute stage, whereas sung stories were learned and recalled significantly better compared with spoken stories at the 6 months poststroke stage. Interestingly, this pattern of results was evident especially in patients with mild aphasia, in whom the learning of sung versus spoken stories improved more from the acute to the 6-month stages compared with nonaphasic patients. Overall, these findings suggest that singing could be used as a mnemonic aid in the learning of novel verbal material in later stages of recovery after stroke.
  • Fromm, Annette; Thomassen, Lars; Naess, Halvor; Meijer, Rudy; Eide, Geir Egil; Krakenes, Jostein; Vedeler, Christian A.; Gerdts, Eva; Larsen, Terje H.; Kuiper, Karel K-J; Laxdal, Elin; Russell, David; Tatlisumak, Turgut; Waje-Andreassen, Ulrike (2013)
  • Saeed, Sahrai; Tadic, Marijana; Putaala, Jukka (2021)
  • Cotlarciuc, Ioana; Marjot, Thomas; Khan, Muhammad S.; Hiltunen, Sini; Haapaniemi, Elena; Metso, Tiina; Putaala, Jukka; Zuurbier, Susanna M.; Brouwer, Matthijs C.; Passamonti, Serena M.; Bucciarelli, Paolo; Pappalardo, Emanuela; Patel, Tasmin; Costa, Paolo; Colombi, Marina; Canhao, Patricia; Tkach, Aleksander; Santacroce, Rosa; Margaglione, Maurizio; Favuzzi, Giovanni; Grandone, Elvira; Colaizzo, Donatella; Spengos, Kostas; Arauz, Antonio; Hodge, Amanda; Ditta, Reina; Debette, Stephanie; Zedde, Marialuisa; Pare, Guillaume; Ferro, Jose M.; Thijs, Vincent; Pezzini, Alessandro; Majersik, Jennifer J.; Martinelli, Ida; Coutinho, Jonathan M.; Tatlisumak, Turgut; Sharma, Pankaj; ISGC Int Stroke Genetics Consortiu; BEAST Investigators (2016)
    Introduction: Cerebral venous thrombosis (CVT) is a rare cerebrovascular condition accounting for <1% of all stroke cases and mainly affects young adults. Its genetic aetiology is not clearly elucidated. Methods and analysis: To better understand the genetic basis of CVT, we have established an international biobank of CVT cases, Biorepository to Establish the Aetiology of Sinovenous Thrombosis (BEAST) which aims to recruit highly phenotyped cases initially of European descent and later from other populations. To date we have recruited 745 CVT cases from 12 research centres. As an initial step, the consortium plans to undertake a genome-wide association analysis of CVT using the Illumina Infinium HumanCoreExome BeadChip to assess the association and impact of common and low-frequency genetic variants on CVT risk by using a case-control study design. Replication will be performed to confirm putative findings. Furthermore, we aim to identify interactions of genetic variants with several environmental and comorbidity factors which will likely contribute to improve the understanding of the biological mechanisms underlying this complex disease. Ethics and dissemination: BEAST meets all ethical standards set by local institutional review boards for each of the participating sites. The research outcomes will be published in international peer-reviewed open-access journals with high impact and visibility. The results will be presented at national and international meetings to highlight the contributions into improving the understanding of the mechanisms underlying this uncommon but important disease. This international DNA repository will become an important resource for investigators in the field of haematological and vascular disorders.
  • Brkic, Biljana Georgievski; Jaramaz, Tatjana Ducic; Vukicevic, Marjana; Stanisavljevic, Natasa; Kostic, Dejan; Lucic, Milos; Marinkovic, Ivan; Apostolovic, Tija; Vlaskovic, Tatjana; Cirkovic, Ana; Marinkovic, Slobodan (2021)