Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is one of the most common forms of hereditary vascular dementia (VaD). Characterised by early-onset strokes and cognitive impairment in the absence of vascular risk factors, CADASIL is an ideal model to understand the pathophysiology of VaD. Pathogenic mutations in the NOTCH3 gene, which encodes a single-pass transmembrane cell surface receptor expressed predominantly in vascular smooth muscle cells (VSMC), cause severe vascular alterations including VSMC degeneration, hyalinosis, deposition of CADASIL-specific granular osmiophilic material (GOM) and white matter (WM) changes. While these changes have been well-described, their causative mechanism or difference between sporadic VaD is poorly understood. The aim of the project was to quantitatively characterise various aspects of cerebral pathology of CADASIL in order to reveal the pathological basis of CADASIL phenotypes, especially of cognitive dysfunction. Firstly, we assessed vascular and perivascular changes in CADASIL brain areas and found significant vessel wall thickening and perivascular space enlargement, even compared to sporadic VaD. Secondly, by using immunogold electron microscopy, NOTCH3 extracellular domain (N3ECD) was located within GOM in the wall of cerebral arteries/arterioles/capillaries, establishing at least one component of GOM and its wide-spread existence in the vasculature. This study also suggested the possible existence of intracellular N3ECD accumulation and involvement of inflammatory response in the pathogenesis of CADASIL. Finally, we provide neuronal density data from the hippocampal formation in CADASIL brains to identify the neural substrates of VaD in CADASIL. Overall, the number of neurons in CA1, CA2 and entorhinal cortex was relatively spared in CADASIL while pyramidal neuronal subpopulation, as shown by SMI32 immunoreactivity, was slightly decreased. In addition, SMI32 staining revealed extensive chronic damage to WM tracts, especially those in the frontal-parietal area. These data suggest that vascular dysfunction and inflammation result in frontal disconnection, which could underlie cognitive impairment in CADASIL patients.

Stroke is the main cause of disability worldwide. With over 110,000 first strokes occurring in the UK every year, the individual and societal burden of stroke will continue to increase. Consequently, there is a pressing need to develop therapies to both reduce the burden of stroke and the risk of stroke recurrence. Hyperglycaemia, dyslipidaemia, hypertension, reduced cardiorespiratory fitness and obesity are metabolic irregularities closely linked to stroke risk and represent possible therapeutic targets. In healthy individuals, a physically active lifestyle and structured exercise have been found to improve metabolic control. Research reporting the impact of physical activity and exercise on metabolic control, stroke risk and wellbeing is lacking in the study of stroke. This thesis aims to define and explore physical activity, exercise and metabolic control following stroke with a view to improving clinical care. A cross-sectional longitudinal study (n=31) demonstrates physical activity levels are low immediately following stroke and do not return to levels comparable to healthy individuals after six months, despite individuals having only mild impairment. A randomised controlled trial (n=40) of a community based exercise intervention post stroke investigated the impact of exercise primarily on metabolic risk factors. Significant improvements occurred in cardiorespiratory fitness (p<0.01); high density lipoprotein cholesterol (p<0.01); and diastolic blood pressure (p<0.04). The intervention also resulted in improvements in cognition, overall stroke recovery and mood, with the most marked changes occurring in walking endurance, walking speed and balance. This thesis delivers two clear messages: physical activity is reduced following stroke and does not fully recover after time; and the reversal of low levels of physical activity with a community based exercise therapy programme provides significant benefit to individuals after stroke. This information suggests that clinicians should consider both the importance of physical activity and the therapeutic potential of structured exercise therapy post stroke.

Stroke services provide patients with immediate assessment and treatment on a hyper acute stroke unit prior to being transferred for intense rehabilitation. Patients' experience of transfer from a hyper acute stroke unit has yet to be explored. A patient's beliefs regarding their illness are important factors that aid a patients' recovery yet these have not been fully explored in patients following a stroke. The aims of this study are to explore the patients' perspectives of transfer from a hyper acute stroke unit to a stroke unit and their itIness beliefs. Data were collected from a purposive sample of patients (n=6) on a stroke unit following transfer from a hyper acute stroke unit. Semi-structured interviews were carried out to explore patients' experience of transfer and their illness beliefs. The interview schedule was based on literature and interviews with a Clinical Nurse Specialist and a stroke patient. Data were analysed using Interpretative Phenomenological Analysis (IPA). The emergent super-ordinate themes included: disassociation from being in the world, search for understanding. strive for independence and acceptance of support, and hope and uncertainty. A chronic illness model of illness representation dimensions emerged; higher reporting of identity, consequences, and timel ine was associated with lower personal and treatment control and an emotional response. Self-regulatory coping strategies and health beliefs within patients following a stroke were identified as important constructs to include in healthcare assessments with the aim of improving psychological, physical and social outcomes.

This thesis examined the application of psychological principles to stroke care. The literature investigating psychological adjustment post stroke was reviewed and the validity of the Distress Thermometer (DT) and Problem List was investigated in an empirical study. A systematic review focussed on the recently published literature using psychological theory to understand what cognitive factors are protective, or not, in the process of adjustment. Twenty papers were reviewed and nine theoretical models of psychological adjustment used. The most commonly referred to model was the Transactional Theory of Stress and Coping (Lazarus & Folkman, 1984). Factors found to be associated with positive mood included internal locus of control, finding meaning and satisfaction with treatment. The complex and dynamic nature of adjustment was highlighted by the role of time and individual differences. The results of the review provided support for a recently developed model of adjustment post stroke (Social Cognitive Transition Model for Stroke, SCoTs, Taylor, Todman & Broomfield, 2011). The DT and stroke specific Problem List offers a valuable tool for assessing and understanding distress post stroke. Forty-eight participants completed the DT, Problem List, Hospital Anxiety and Depression Scale (HADS, Zigmond & Snaith, 1983), Brief Assessment Schedule Depression Cards (BASDEC; Ashead et al, 1992) and the Visual Analogue Mood Scale Revised (Kontou et al., 2012) at one time point. Correlation coefficients were significant and positive between all measures, supporting concurrent validity. AUC analysis suggested a cut-off of 4.5 on the DT as suitable for the detection of anxiety. Cronbach's alpha found the Problem List to be most reliable when used as one whole scale, however this was most likely because of the large number of items in the overall scale, rather than the items being clearly associated to one another. Bladder and bowel problems were the most commonly reported distressing problem, with fatigue, worry and depression being frequently identified. These findings supported the used of the DT and Problem List in the early stages post stroke.

The purpose of this thesis was to inform the development of a complex intervention for improving secondary stroke prevention in people who have experienced a Transient Ischaemic Attack (TIA). The work was guided by the Medical Research Council (MRC) framework for the development and evaluation of complex interventions. A mixed methods approach was taken, incorporating three inter-related studies. The first study was an audit investigating the quality of secondary stroke prevention in primary care following diagnosis of TIA in a specialist clinic. The second study was a systematic review of randomised controlled trials evaluating the effectiveness of stroke service interventions for secondary stroke prevention. The third study was a qualitative study, involving 20 interviews with TIA patients, using a discursive psychology approach to explore barriers and facilitators to secondary stroke prevention. Key findings: • Results of the audit demonstrated that monitoring and achievement of risk factor control in primary care was suboptimal; potential areas for quality improvement included blood pressure (BP) control, lipid control and provision of dietary and exercise advice. • Findings from the systematic review indicated that organisational interventions were associated with significant reductions in mean systolic BP, diastolic BP and body mass index (BMI). • The qualitative study, through an analysis of the ‘action-orientation’ of participants’ accounts, identified discursive features that functioned to justify adherence or non-adherence to recommendations for secondary stroke prevention. The key findings from these studies indicated that an organisational intervention should be developed based on the principles of integrated care. The qualitative study provided insights for understanding and optimising the intervention. Based on these findings, recommendations are made for further intervention development work. The findings also have relevance to the development and application of the MRC framework; efforts should be directed towards developing practical guidance for the integration of mixed methods research.

Ischaemic stroke instigates a series of pathological mechanisms which contribute to injury. Despite significant research in this field successful clinical treatment is limited. This highlights the need to identify novel therapeutic targets in order to assess whether clinical investigation is warranted. The enzyme cyclooxygenase-2 (COX-2) is a key contributor to inflammatory injury following stroke. Upregulation of this enzyme results in increased prostanoid synthesis, which mediate many physiological and pathological functions. Prostaglandin E₂ (PGE₂) is a key mediator in inflammation and activation of its receptor subtypes is both neuroprotective and neurotoxic. COX-2 inhibition in animal models of stroke has demonstrated neuroprotection. However, long term arthritis trials have revealed detrimental effects of COX-2 inhibitors. This highlights the need to identify mediators of the detrimental effects of COX-2 and capitalise those that mediate the beneficial effects. The aim of this study was to investigate the role of the PGE₂ receptor EP₄ following in vitro and in vivo ischaemia. Organotypic hippocampal sliced cultures (OHSCs) were exposed to oxygen and glucose deprivation (OGD). Treatment with a selective EP₄ agonist following OGD significantly reduced cell death, whereas application of the EP₄ receptor antagonist exacerbated injury. C57/BL6 mice were subjected to focal cerebral ischaemia via middle cerebral artery occlusion (MCAO). Administration of the selective EP₄ agonist significantly reduced infarct volume and prevented the decline in neurological function. COX-2 inhibition and EP₄ receptor stimulation resulted in similar levels of protection both in vitro and in vivo ischaemia. EP₄ receptor expression was assessed using immunohistochemistry and real time-PCR. This study provides evidence that selective activation of the EP₄ receptor following ischaemic injury is as neuroprotective as COX-2 inhibition but possibly without the deleterious side effects of COX-2 inhibitors. This supports the concept of targeting protective prostaglandin receptor signalling as a potential therapeutic target for stroke.

Objective: To determine the accuracy and appropriateness of screening measures for detecting low mood and cognitive impairment in acute stroke patients, by determination of their sensitivity, specificity and reliability. Methods: 114 English-speaking acute stroke patients completed a depression screening measure from the Mood Assessment Care Pathway (MACP), a battery of mood assessment measures and the Structured Clinical Interview for DSM-IV Axis 1 Disorders (SCID). Participants without significant physical or language impairment additionally completed the Middlesex Elderly Assessment of Mental State (MEAMS), an oral paradigm of the Trail Making Test (OTMT) and detailed neuropsychological assessment with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Rule Shift Card Test (BADS) and the Verbal Fluency Test (phonemic task). Results: 106 participants completed all of the mood assessment procedures. Sensitivity of the individual MACP measures was generally high for the detection of major and minor depression. Specificity varied widely between the measures ranging from 18% to 85% but was generally within acceptable levels (greater than 60%). A revised version of the MACP was proposed using optimal cut-off scores. The MACP-revised gave 100% sensitivity and 77% specificity for the detection of major depression and 81% sensitivity and 65% specificity for minor depression. Reliability as assessed by the Kappa coefficient was found to be generally low for either version of the MACP and the individual measures. 91 participants were assessed using the MEAMS. Convergent validity of the MEAMS with full assessment measures was not supported (r < .40). Overall, sensitivity of the MEAMS subtests and the overall MEAMS for the detection of impairment in any of the cognitive domains was generally low, except for the overall MEAMS with Immediate and Delayed Memory Impairment. Specificity was generally higher, but there were only two instances where subtests achieved acceptable levels of both sensitivity and specificity. The overall MEAMS failed to achieve acceptable levels of agreement for any of the cognitive domains assessed. 89 participants were assessed using the OTMT. Sensitivity of the OTMT-B for the detection of impairment in any of the cognitive domains was generally low (less than 60%). Specificity was generally higher (greater than 76%), but there were no instances where acceptable levels of sensitivity and specificity were both achieved. Agreement with full assessment measures was generally poor for any of the cognitive domains assessed. Conclusions: The overall MACP-revised was an acceptably valid screening battery for the assessment of major and minor depression in acute stroke patients and demonstrated a useful way of compiling mood screening batteries which allow the assessment of mood impairment for all stroke patients. Neither the MEAMS nor the OTMT were recommended as a measure for screening for cognitive problems after a stroke due to their low sensitivity. However, further investigation of the psychometric properties of the RBANS was indicated, as the current findings suggest that it can be successfully used to assess acute stroke patients for cognitive impairment.

Our approach in identifying candidate genes for ischaemic stroke involved the selection and genotyping of common polymorphisms of genes which may influence one of the major risk factors for stroke. Materials and Methods. DNA from Caucasian populations of control subjects and stroke patients was made available for PCR and subsequent genotyping, which included RFLP analysis, DASH and microsatellite analysis. Our chosen genes included the GNbeta3 gene (the C825T polymorphism), the p22PHOX gene the C242T and A640G polymorphisms) and the ERalpha gene (the PvuII, XbaI SNPs and TA dinucleotide tandem repeat polymorphism). Statistical tests were then used to determine whether genotype/allele frequencies were significantly different in case-control analyses. Where appropriate (multiple markers investigated), haplotype analysis was also performed to test for linkage disequilibrium. In addition, we collaborated with deCode Genetics (Iceland) on the genotyping of 5 novel SNPs and 2 microsatellite polymorphisms on an Icelandic stroke population as well as our own Scottish stroke patients. Results. From our results, there were no positive associations revealed with any of the three candidate genes. However, through our collaboration with deCode Genetics, two polymorphisms (1 SNP and 1 microsatellite) were found to be significantly associated with ischaemic stroke in both Icelandic and Scottish patient populations. Haplotype analysis of these two markers also revealed a significant difference between cases and controls. Discussion. The future success of population association studies of complex disorders will require replication of both negative and positive findings in geographically/ethnically different populations. Identification of the potential "stroke" gene on 5q12 may lead to identification of novel therapeutic targets.

No description available.

The main aim of this project was to identify likely candidate genes in ischaemic stroke from a population in North-East Scotland. SNP allele frequencies were investigated for significant differences between case and control pools to identify chromosomal regions likely to contain relevant genes. In this way, 43 candidate genes for ischaemic stroke were identified.  Two had previously been found by other studies (ALOX5AP and PDE4D), and several interact with each other in a particular biochemical pathway. Moreover, the majority of genes identified could be grouped into four main disease processes – lipid metabolism, atherosclerosis, inflammation and apoptosis.  These are all either known risk factors for, or characteristic of, Stroke and therefore strengthen our confidence in these results. In a separate study, polymorphisms in two candidate genes (PPP1R3, implicated in type II diabetes, and PLAT, involved in the development of stroke) were selected for individual grouping genotyping in available samples on the basis of previous studies and literature searches. Results were conflicting: no association with stroke sub-type was found for any polymorphism in the PLAT gene, while only one PPP1R3 SNP was significantly reduced in small and large vessel disease (but not cardio-embolic) stroke cases compared to controls.  On the other hand, a common ATTTA deletion was associated with cardio-embolic strokes. Haplotype analysis in PPP1R3 showed one combination to be more frequent in cases overall than controls. These experiments highlighted the complex nature of stroke genetics, and also emphasised the usefulness of studying intermediate phenotypes to identify the genetic basis of common, complex disorders. In addition, DNA pools combined with microarrays are a powerful, efficient means by which to identify novel candidate genes relatively quickly.