Introduction: Medulloblastoma is an aggressive malignant neuro-ectodermal tumour of the cerebellum which accounts for 15-20% of childhood central nervous system tumours and frequently disseminates to the leptomeningeal spaces of the brain and spinal cord. Patients with disseminated disease respond poorly to post-surgical multimodal treatment which is thought to be explained by the intrinsic drug-resistant nature of these tumours. Here, we hypothesized that cells gain migratory and invasive capabilities by undergoing an Epithelial-Mesenchymal Transition (EMT)-like process whereby cells alter phenotypically and acquire stem cell-like properties during tumour dissemination. In this study, metastatic genes were identified and tested using 3D in vitro model systems which incorporated important components of the extracellular matrix. Using these markers, evidence for an EMT-like process and the role of the multi-drug transporter, ABCB1, was investigated in metastatic medulloblastomas. Small molecule inhibitors were also used to investigate whether metastatic processes could be targeted and drug resistance mechanisms could be circumvented in both in vitro and/or in vivo settings. Materials and Methods: Growth, morphology and biological processes (e.g. cell migration) were assessed in a panel of non-metastatic and metastatic medulloblastoma cell lines, as well as in non-tumourigenic neural stem cells cultured in a 3D basement membrane extract (BME) using the alamar blue assay (measure of metabolic activity) and time-lapse imaging. Putative metastatic markers were identified through literature review analysis of gene expression datasets or immunohistochemistry of tissue micro-arrays (TMA). These markers were then assessed in samples obtained from medulloblastoma cell lines cultured as 2D monolayers and grown in BME (for 3 and 6 days) by QRT-PCR analysis. Protein expression of selected markers were also assessed in mouse orthotopic xenograft samples by immunohistochemistry or in cell lines using immunofluorescence analysis. Finally, small molecule inhibitors (WIP1 and ABCB1 inhibitors) were used in 3D culture systems (3D spheroid and 3D BME assays) and in an orthotopic metastatic mouse model. Results: Medulloblastoma cell lines demonstrated different growth patterns in 3D. Metastatic cell lines formed metabolically active aggregates which sustained continual cell migration for at least 6 days; whilst non-metastatic and non-tumourigenic cells showed low metabolic activity and rapidly differentiated. Metastatic cell lines which were sustained longest in BME (D283 Med and MED1) demonstrated upregulation of the EMT transcription factor, TWIST1, along with several other EMT and TWIST1-related factors. Further analysis included overexpressing TWIST1 in a non-metastatic cell line (MED6 TWIST1) which induced a dispersed phenotype in 2D and cell aggregation in the 3D BME model which phenotypically resembled metastatic cell lines. TWIST1 and ABCB1 expression correlated with metastasis in patients and was upregulated in the invasive edge of primary tumours and in spinal metastases in an orthotopic metastatic mouse model. Small molecule inhibitors targeting WIP1 (a published metastatic marker) and ABCB1 inhibited cell migration of metastatic cell lines grown in 3D including the MED6 TWIST1 cell line. ABCB1 inhibition also increased sensitivity to etoposide treatment in 3D spheroid models and an orthotopic metastatic in vivo model. Conclusion: The 3D BME model utilised in this study can be used to distinguish metastatic capacity and transcriptional changes of medulloblastoma cell lines. Furthermore, data from this study supports a role for a TWIST1 driven EMT-like process in metastatic medulloblastoma and supports the use of ABCB1 inhibition to overcome chemoresistance.

Primary Intracerebral haemorrhage is a severe form of stroke with poor prognosis attributed to haematoma characteristics. High blood pressure is present during the acute phase of intracerebral haemorrhage and associated with poor outcome in part through expansion of haematoma. Data from the ‘Efficacy of Nitric Oxide in Stroke trial’ (ENOS) was used to analyse the performance characteristics of qualitative and quantitative descriptors of intracerebral haematoma. The results showed that formal measurement of haemorrhage characteristics and visual estimates are reproducible. Intracerebral haemorrhage volumes measured using the modified ABC/2 formula were significantly lower compared to standard ABC/2 and computer assisted semi-automatic segmentation. In 629 patients with intracerebral haemorrhage presenting within 48 hours, the effect of blood pressure lowering with transdermal glyceryl trinitrate was assessed. Glyceryl trinitrate lowered blood pressure, was safe but did not improve functional outcome. In a small group of patients treated within 6 hours, glyceryl trinitrate improved functional outcome. Analysis of 246 patients with acute intracerebral haemorrhage from ENOS was undertaken to assess whether there were any differences in functional outcome among those who continued prior antihypertensive drugs during the immediate stroke period compared to those assigned to stop temporarily for 7 days. The results were neutral indicating that there was no benefit in those who continued treatment. Data of 1,011 patients with intracerebral haemorrhage in hyperacute trials from the VISTA collaboration showed differences in baseline characteristics and functional outcomes among patients from various ethnic backgrounds. A systematic review was updated to assess the effect of 26 randomised controlled trials that aimed to alter blood pressure within one week of acute stroke. The results showed that blood pressure reduction did not improve functional outcome irrespective of stroke type. When examined by time, treatment within 6 hours appeared to benefit but the number of patients were small and more studies are needed. The analysis also showed that continuing prestroke antihypertensive drugs in the immediate period after stroke did not benefit and might be harmful. In summary, this thesis provides new information on parameters used to estimate intracerebral haematoma, relationship between management of blood pressure and outcomes after haemorrhagic stroke. The work supports testing of whether very early blood pressure lowering after ictus is beneficial as is being undertaken in ongoing randomised controlled trials. Adjusting for ethnic differences may further identify patients in whom treatment may confer measurable advantage.

Functional brain networks are interconnected brain regions that flexibly coordinate their activity to support cognitive demands (Fair et al., 2009). Functional brain connectivity describes a statistical dependency between the activities recorded at spatially distinct brain regions (Friston, 2009). Changes in the pattern of connections and level of activation in functional brain networks are thought to occur across development (Taylor, Donner, & Pang, 2012) but the nature of these changes and their relationship to cognitive development have yet to be delineated clearly. This thesis seeks to deepen our understanding of the development of functional brain connectivity across the age range 9-25 years. We used magnetoencephalography in conjunction with canonical correlation analysis to explore functional connectivity via amplitude-amplitude envelope correlations in 110 datasets (39 working memory, 33 relevance modulation (attention processing) and 38 resting state). At the core of this thesis, we have presented novel findings that show non-linear functional connectivity changes across development, with an increase from childhood (age 9-12) to late adolescence (age 17-20) followed by a reduction into young adulthood (age 21-25), resembling an inverted-U-shaped trajectory at least in the females included in this study. Whilst there are subtle yet statistically significant differences in how the functional connectivity profile from 1-100 Hz is modulated by different factors, the overall pattern of functional connectivity development appears to be remarkably consistent across cognitive demands and networks. Critically, this work is the first example of such findings and suggests that functional brain networks supporting higher order cognitive function are not alone in undergoing functional development; sensory networks that reach structural maturity early on in life also undergo functional development from age 9 to 25.

Stroke is a highly prevalent condition. It is a principal cause of adult disability and a leading cause of death in the United Kingdom (UK). The lifetime risk of stroke recurrence is also high, particularly for those with specific risk factors (e.g., hypertension). The long-term management of stroke is multi-faceted and complex. Stroke survivors are often responsible for self-managing their secondary preventive treatment (e.g., oral medication(s)) alongside rehabilitation, which is most beneficial in the first six-months. However, patients undergo a period of psychological adjustment after stroke. This is particularly evident in the early days where mood problems, such as depression, are highly common and affect how well people engage with, and adhere to, their rehabilitation and treatment. The present PhD research was interested in further understanding adjustment after stroke, and in particular, by utilising key evidence from the field of Health Psychology (more specifically, the Common Sense Model (CSM)), examining whether survivors’ perceptions (or beliefs) about their stroke are influential in determining how well people recover. The overall aims of this work were to: • Examine and synthesise the current evidence, through a systematic review and meta-analysis on the CSM in relation to physical illnesses to determine whether individual illness belief domains were important predictors of adherence to self-management in adults with acute or chronic conditions; • Elicit views regarding an assessment method (the Stroke Illness Perception Questionnaire-Revised (Stroke IPQ-R)) that would be suitable and acceptable to a stroke population for accurately measuring peoples’ beliefs in the acute phase (≤three-months post-stroke); • Apply the CSM (utilising the Stroke IPQ-R) to a population within the acute phase of stroke, to determine whether the model provides a useful framework for understanding survivors’ recovery after stroke (e.g., Health-Related Quality of Life (HRQL), disability, and mood). This research incorporated three standalone though inter-related studies, the first of which was a systematic review and meta-analysis. The key findings from this meta-analysis indicated that the majority of illness belief domains outlined by the CSM significantly predicted (albeit weakly) adherence to a range of self-management behaviours (e.g., attendance; medication adherence; diet; physical activity; and other disease-specific behaviours (e.g., blood glucose self-monitoring)). Pooled effect sizes ranged from 0.04 and 0.13. None of the relationships varied according to acute and chronic illnesses; the type of self-management behaviour; or the duration of follow-up. A qualitative study was subsequently undertaken. A variety of approaches were employed (including, expert consultation and Think-Aloud interviews) to develop a stroke-specific version of the IPQ-R. Interview findings showed very few problems with completion of the instrument. Where there were problems, these related to the wording of items, specifically abstract, complex and negative wording; the response format for the identity sub-scale; and questions on the timeline-cyclical and treatment control sub-scales. The revised scale was used in the third and final study. The final study examined the relationship of illness beliefs, assessed by the Stroke IPQ-R developed in study 2, and measures of post-stroke recovery, including HRQL, disability and mood. This was a longitudinal observational study involving 50 survivors (average age=66.9 years, standard deviation =14.5 years) within three-months of their stroke. The primary outcome for this study, HRQL, was measured using the EQ-5D-5L instrument. The secondary outcomes were: disability, which was assessed using the Barthel Index, Modified Rankin Scale, and Nottingham Extended Activities of Daily Living Scale; and mood, measured using the Patient Health Questionnaire-9. Various statistical approaches were employed in the analyses of these data, the results of which are as follows. Spearman’s correlations indicated that participants who perceived their stroke to have fluctuating effects and considerable distress at baseline ( < eight-weeks post-stroke) also reported worse mood one-month later. Multiple mediation analyses were conducted to examine whether baseline mood and coping (follow-up medication adherence, measured using the Medication Adherence Report Scale) mediated any of these relationships. The results indicated that baseline mood rather than coping was a significant mediator in the prediction of worse mood three-months post-stroke. Multiple linear regression analyses were carried out to determine whether baseline illness belief domains explained the additional variance in three-month HRQL, disability and mood, over and above that explained by socio-demographic (e.g., age, gender, and deprivation) and clinical variables (e.g., baseline co-morbidities, stroke severity, and indices of recovery). The findings indicated that baseline illness belief domains significantly added between 7.4 and 29.9% to the overall variance in models for the majority of the abovementioned outcomes. Last, the results from the study demonstrated that baseline illness belief domains were highly significantly inter-correlated at baseline, and with follow-up illness belief domains. In light of this, cluster analysis was carried out to explore whether stroke survivors in the acute phase could be grouped according to their illness belief schema. Three clusters were identified: ‘Low Adjusters;’ ‘Moderate Adjusters;’ and ‘High Adjusters.’ In contrast to ‘High Adjusters,’ Low Adjusters’ were participants who perceived their stroke to be chronic, with fluctuating effects, associated with a lot of symptoms, serious consequences and considerable distress. While baseline cluster membership was not significantly related to follow-up markers of post-stroke recovery, there were trends to suggest that ‘Low Adjusters’ had worse HRQL and mood, and greater disability one-month later compared to ‘High Adjusters.’ The present research had several important implications. The principal theoretical implication concerns treatment beliefs. The findings from all three studies highlighted that people’s beliefs about the effectiveness of their treatment in managing their condition are examined in the CSM in a limited way. There is currently a substantial focus on medication-taking behaviours despite treatments often being more complex (e.g., lifestyle behaviour or surgery). Therefore, the findings indicated that there is scope to further elaborate this domain, above and beyond what has already been undertaken in the Necessity and Concerns Framework. This examines the cost versus benefits decision-making that patients undergo when taking their medication(s) (Horne and Weinman 1999). In addition, suitable instruments need to be further adapted and validated to accurately measure these treatment beliefs. There were also several clinical implications of this work. First, it was emphasised that mood assessments should be carried out in patients immediately after stroke. It was shown in this research that even mild depressive symptomatology affected peoples’ beliefs about their stroke, and thus how well they psychologically adjust in the acute phase. Second, there is a potential to develop brief belief-based interventions for modifying maladaptive beliefs about stroke. For instance, addressing perceptions around the fluctuating effects of stroke and the considerable distress caused by stroke could form the basis for such interventions. In addition, interventions can be targeted to a particular type of stroke survivor (i.e., ‘Low Adjusters’), who are likely to be the people to benefit most from receiving them. However, these findings need to be borne out in a larger sample beforehand. The primary methodological consideration in relation to this work was the logistics of recruiting stroke survivors in the acute phase, which led to issues including: a small sample size; sample non-representativeness; and statistical constraints (e.g., factor analysis).

Sensory gating is a mechanism by which irrelevant sensory information is filtered in the brain, enabling efficient information processing. The auditory conditioning-test paradigm, an index of sensory gating, measures the reduction in the auditory-evoked response (AER) produced by a test stimulus following an initial conditioning stimulus. Schizophrenic patients demonstrate a lack of attenuation of the test response measured in the P50 component of the cortical auditory-evoked potential. The N2/N40 auditory-evoked potential recorded from rat hippocampus is considered homologous to the human P50 wave. Altered glutamatergic neurotransmission and the endocannabinoid system have been implicated in the pathogenesis of schizophrenia with structural and functional abnormalities in the hippocampus and the medial prefrontal cortex (mPFC). The current study examined sensory gating using auditory conditioning-test paradigm in the dentate gyrus (DG) and the CA3 region of the hippocampus and in the medial prefrontal cortex (mPFC) before and after administration of N-Methyl- D-Aspartate (NMDA) receptor antagonist phencyclidine (PCP; 1 mg/kg, i.p) or the cannabinoid agonist WIN55,212-2 (1.2mg/kg, i.p). Electrophysiological recordings were conducted in Lister hooded rats, under isoflurane anaesthesia, during the presentation of paired auditory stimuli. Extracellular action potential spikes and local field potentials (LFPs) were recorded simultaneously using multi-electrode arrays and the effects of acute administration of PCP (1 mg/kg, i.p) or WIN55,212-2 (1.2mg/kg, i.p) was determined. Gating of the N2 wave was assessed by measuring the ratio of the Test to Conditioning response amplitude (T/C ratio); T/C ratio ≤ 50% was indicative of gating. Robust auditory-evoked potentials were recorded from the hippocampal CA3 and DG regions and the mPFC; some rats demonstrated auditory gating while others failed to. In rats that demonstrated gating of N2, mPFC showed higher T/C ratios and shorter conditioning response latencies compared to DG and CA3. PCP disrupted auditory gating in all three areas with a significant increase in test response amplitudes in the gating rats. PCP had no effect on T/C ratios in the non-gating rats. The atypical antipsychotic clozapine (5mg/kg, i.p) prevented PCP induced disruption of gating in the CA3, DG and mPFC. WIN55,212-2 disrupted auditory gating with a significant increase in test response amplitudes in the gating rats. WIN55,212-2 had no effect on T/C ratios in the non-gating rats. The cannabinoid receptor (CB1) antagonist SR141716A (1mg/kg, i.p) prevented WIN55,212-2 induced disruption of gating. Neither clozapine nor SR141716A had any effects on the non-gating rats. Both PCP and WIN55,212- 2 disrupted gating of the single-unit responses in the CA3, DG and mPFC, effects which were prevented by the pre- administration of clozapine or SR141716A. The non-gating rats may model some inhibitory deficits observed in schizophrenic patients. Administration of PCP disrupted auditory gating which was prevented by clozapine; similar deficits are observed in schizophrenic patients. Furthermore, cannabinoid receptor activation disrupted auditory gating which was prevented by CB1 receptor antagonism, suggesting the endocannabinoid system as a potential target for future clinical research in the treatment in schizophrenia.

This thesis describes the study of the neurochemistry of Huntington's disease using a large series of post mortem brain tissue taken from patients with Huntington's disease and from matching controls with no previous history of neuropsychiatric disorder. There were two main aims: firstly, to identify and characterise any altered parameters of neurotransmitter systems, especially in relation to the symptomatology of the disease; secondly, to understand the role of neurotoxins in the aetiology of the disease, particularly endogenous compounds that may have derived from aberrant metabolism. Concentrations of the amino acid transmitters, GABA and glutamate, were generally significantly decreased throughout the brain in Huntington's disease, including cortical and limbic regions. Cortical deficits were not associated with the dementia of the disease, whereas caudate levels of GABA and glutamate showed a relationship with the dementia. In patients with severe chorea, the medial pallidum was found to have a relatively smaller GABA deficit than mildly choreic patients. Another novel finding was that 5HT and 5HIAA concentrations were significantly increased in most regions of the brain in Huntington's disease, perhaps reflecting abnormal tryptophan metabolism. Such changes in the cortex provide evidence for a cortical involvement in the disease. Dopamine metabolism appeared to be reduced in Huntington's disease, reflected by the significantly decreased concentrations of its major metabolite, homovanillic acid, in most regions except for the cortex (where it was increased). Neuroactive compounds of the kynurenine pathway of tryptophan metabolism were measured in Huntington's disease. Quinolinic acid concentrations were not significantly altered, however 3- hydroxykynurenine concentrations were significantly increased in the striatum and cortex. This provides the first evidence for increased concentrations of an endogenous neurotoxic compound in the brain in Huntington's disease.

Background: Recent studies have shown that the two major forms of multiple sclerosis are different in the degree of demyelination and atrophy, degree of inflammation, and extent of axonal loss. However, the majority of the previous studies that compared primary progressive and secondary progressive multiple sclerosis were carried out at the brain level. Material and methods: Human post-mortem spinal cords were used to compare the two progressive subtypes. In this project, the 5 major pathological changes associated with MS were studied in the spinal cords of primary progressive and secondary progressive multiple sclerosis. These changes include degree of demyelination, atrophy of the tissue, oligodendrocytes pathology, axonal loss, and neuronal pathology. Results: There was significant atrophy in the spinal cords of MS compared to healthy controls, which affects mainly the upper cord levels. There is a greater degree of demyelination and atrophy affecting secondary progressive compared to primary progressive especially in the upper cord levels. Oligodendrocytes numbers are dramatically reduced in the chronic lesions of WM and GM lesions. But there was high numbers of oligodendrocytes in the normally appearing GM of secondary progressive multiple sclerosis. There was greater reduction in axonal density in the secondary progressive sample especially in the normally appearing WM. Neurons were reduced in the demyelinated grey matter regions with no difference between the two disease forms in this respect. Conclusions: SPMS seem to have greater degree of tissue destruction in the form of demyelination, atrophy, and axonal loss in the normally appearing WM. However, SPMS showed greater numbers of oligodendrocytes in the demyelinated areas of the WM and the GM. Although the disability scale in the two examined groups was found to be similar, the tissue damage appeared to be variable.

The aim of the study was to investigate the assessment and treatment of stance symmetry and sway after stroke and was divided into 3 parts. Stage 1. Sway and stance symmetry were surveyed with the Nottingham Balance Platform (NBP), a computerised limb load monitor. Over 400 volunteers of both sexes and a wide age range were recruited. There were significant differences between the sexes for both sway (p<0.05) and stance symmetry (p<O.Ol) and significant correlations between age and sway (p<O.OOl) and stance symmetry (p<O.OOl). Thus, normative data was provided. Stage 2. Patients were surveyed to examine these variables after stroke and their relationships with age, falls and motor and ADL function. A consecutive sample of 92 patients underwent 2 assessments, 4 months apart, between 2 and 9 months post-stroke. Abnormal stance symmetry was seen, which improved with time (p<O.01) and correlated with functional measures (p<.001), length of stay and age. Abnormal sway values also present, improved with time (p<O.Ol). A significant relationship existed between sway values and falls frequency (p<O.01), but there was no significant association with functional abilities, age or sex. Stage 3. A single-blind randomised-controlled trial was conducted with 26 stroke patients to assess the value of visual feedback training. Patients demonstrating asymmetry were randomly allocated to two groups. Group A received visual feedback and Group B a placebo program, incorporated into 12 physiotherapy sessions. Independent assessments of motor and ADL function were completed at the start (0 weeks) and end of treatment (4 weeks) and at 8 weeks. Initially, there were no significant differences between the groups. At 4 weeks, stance symmetry and measures of function were significantly better for the treatment group than controls (p<0.05), but not at the final assessment. The improvement, although maintained, did not continue after treatment. The results support the further use of feedback techniques to improve standing posture after stroke.

Poor pain assessment contributes to inadequate postoperative pain relief. Studies in the US suggest that nurse education might make students less sensitive to patients' experience of pain. This research set out to examine this process in the United Kingdom and to explore the experience of the students during their common foundation programme (CFP). 217 students completed the Standard Measure of Inferences of Suffering Questionnaire (SMIS) before and after their CFP. Their inferences of psychological distress increased as studies in the US had found but unlike these studies no change was found in their inferences of pain. Inferences of pain and psychological distress were affected by the age of the cases, while gender affected only the latter. None of the characteristics of the students were related to their inferences Of 51 qualified nurses who completed the SMIS, 5 with high inferences and 5 with low inferences, rated patients for whom they were caring. Over half of their ratings were different from those of the patients' and there was no relationship between their SMIS scores and the tendency to over or under estimate patients' pain casting doubt on the validity of the SMIS. Interviews with 15 students following their CFP showed that they experienced a wide range of strong emotions when caring for patients in pain. Their relatively junior status in the wards seemed to place them in difficult positions and provided them with little support. Theories of desensitisation, cognitive dissonance and acculturation have been proposed to explain decreasing sensitivity to pain. The lack of a significant change in students' inferences of pain and the analysis of their interviews suggest that their experiences are more varied than these theories suggest. These findings have important implications for both nurse education and the mechanisms to support student nurses in clinical practice.

Perceptual problems are common following stroke and affect the patients' functional ability, suggesting that these problems should be treated. Eighty patients admitted to the Nottingham Stroke Unit, were assessed for perceptual and functional abilities, using standardised assessments (Rivermead Perceptual Assessment Battery, Barthel ADL Index and Edmans ADL index). Each patient identified as having perceptual problems, was randomly allocated to one of two groups for perceptual treatment. One group followed the transfer of training approach and one group followed the functional approach. The study compared the effectiveness of the two approaches in improving perceptual and functional abilities. Treatment was given for 2.5 hours per week for six weeks. On completion of the six weeks treatment, each patient was reassessed for perceptual and functional abilities. There was no significant difference between the treatment groups on patient characteristics or impairments. The results also showed no significant difference between the treatment groups before and after treatment on perceptual ability total scores, individual perceptual subtest scores, or functional ability total scores (Mann Whitney U 642.5-798.0, p > 0.05). Wilcoxon Matched Pairs Signed Ranks Tests showed a significant improvement after treatment, on perceptual and functional abilities, (perceptual z = 6.02, p<0.001, functional z = 6.72, p<0.001). These results indicated the improvement in perceptual abilities was equivalent using either of the two approaches. Therefore, a no treatment group of 20 patients was studied. The results showed similar results between the treatment and no treatment groups, suggesting that neither treatment approach improved outcome. However, these results may have been influenced by spontaneous recovery or the effects of the Stroke Unit.