Browsing by Author "Barber, Philip A."

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    Development of a Model of Recurrent Stroke Consisting of a Mild Transient Stroke followed by a Second Moderate Stroke in Rats
    (Elsevier, 2009) Qiao, M.; Zhao, Zonghang; Barber, Philip A.; Foniok, T.; Sun, S.; Tuor, Ursula I.
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    Diffusion Tensor Imaging and Cognition of Transient Ischemic Attack Patients and Healthy Controls
    (2018-05-11) Tariq, Sana; Barber, Philip A.; Longman, Richard Stewart; Smith, Eric Edward
    Currently, there is no cure for dementia and prevention trials need to be redesigned with a focus on high-risk population and standardized biomarkers, which include clinical, demographic, imaging and neuropsychological considerations. Transient Ischemic Attack (TIA) patients are at an increased risk of dementia due to the presence of vascular risk factors and underlying vascular/neurodegenerative pathology. We hypothesized that at baseline TIA patients will exhibit abnormal microstructural white matter (WM) changes as measured by diffusion tensor imaging (DTI) parameters, and that these parameters will predict worse cognitive outcomes. Our results suggest that TIA patients showed higher axial diffusivity (AxD), mean diffusivity (MD) and radial diffusivity (RD) parameters in the fornix, a tract crucial for memory, and lower fractional anisotropy (FA) overall when compared to healthy controls. TIA patients also performed poorer on tests of executive function, episodic and working memory, and processing speed. DTI parameters of FA and MD predicted performance in tests of executive function and memory but not processing speed. Considering these results, TIA patients are a high-risk population for cognitive change.
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    Infrared optical imaging of matrix metalloproteinases (MMPs) up regulation following ischemia reperfusion is ameliorated by hypothermia
    (BioMed Central, 2012) Barber, Philip A.; Rushforth, David; Agrawal, Smriti; Tuor, Ursula I
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    Reduced blood brain barrier breakdown in P-selectin deficient mice following transient ischemic stroke: a future therapeutic target for treatment of stroke
    (BioMed Central, 2010-02-02) Jin, Albert Y.; Tuor, Ursula I.; Rushforth, David; Kaur, Jaspreet; Muller, Robert N.; Petterson, Jodie Lee; Boutry, Sébastien; Barber, Philip A.
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    Whole-Brain Atrophy Rates, Regional Cerebral Blood Flow, and Cognitive Profiles of Transient Ischemic Attack Patients and Controls
    (2019-06-18) Reid, Meaghan; Barber, Philip A.; Sajobi, Tolulope T.; Coutts, Shelagh B.; Longman, Richard Stewart
    Dementia is one of the most common causes of disability amongst the old and the prevalence is expected to double within the next twenty years. Recent prevention trials have failed to find a cure, likely due to inappropriate trial selection and a lack of reliable outcome measurements. Standardized clinical, demographic, imaging and neuropsychological biomarkers will improve selection criteria and therapeutic interventions. Transient ischemic attack (TIA) patients are at an increased risk of late-life cognitive decline due to their common vascular risk factors with dementia and underlying cerebrovascular pathology. We hypothesized that TIA patients would have increased longitudinal rates of cerebral atrophy as measured by T1 magnetic resonance (MR) imaging compared to non-TIA controls over 1 year and that increased cerebral atrophy rates would be associated with poorer cognitive outcomes. Secondly, we hypothesized that at baseline TIA patients would have lower regional cerebral blood flow (CBF) as measured by arterial spin labelled (ASL) MR imaging compared to non-TIA controls, and that CBF would be associated with cognition. Our results suggest that TIA patients show almost double the cerebral atrophy rates of non-TIA controls over 1-year, and in the absence of demonstrated change in cognition, supports that these subjects with TIA are in a preclinical stage of cognitive decline. Our results also show that TIA patients have reduced CBF in the left entorhinal cortex, the posterior cingulate bilaterally and the right precuneus which was associated with poorer memory outcomes. These predictors of early neurodegeneration and vascular changes show that TIA patients are a high-risk population for dementia and could improve inclusion criteria for clinical trials to prevent dementia in the future.