Stress-related cognitive changes are still a matter of debate. In some particular neuropathological conditions such as focal ischemia, cognitive functions have been shown to be significantly impaired. These conditions, however, may be improved by some factors such as steroid hormones. The purpose of the current thesis was to assess the structural and functional effects of corticosterone-related experiences on the hippocampus before and after endothelin-1 (ET-1)-induced stroke. We found corticosterone-related experiences enhance the hippocampal recovery, and improve its function in both wet and dryland tasks after ET-1-induced focal stroke. Structural and functional effects of such experiences prior to the focal ischemia in the hippocampus, however, showed that stress, not corticosterone is a strong inhibitor for hippocampal recovery. / xii, 252 leaves : ill. ; 29 cm. --

The present thesis examines the effects of transcranial direct current stimulation and forelimb rehabilitation on motor recovery after stroke in rats. Post-stroke motor outcomes were quantified using an innovative battery of behavioural tests and high resolution, in vivo electrophysiology was employed to examine coherence of neural activity between hemispheres. It was shown that rats that received brain stimulation concurrently with forelimb rehabilitation displayed functional recovery, whereas rats that received rehabilitation alone partially regained motor function, but the improvements were not due to restitution of original movement patterns. Results from electrophysiological recordings showed that rats that received brain stimulation and rehabilitation regained pre-stroke levels of interhemispheric coherence, but rats that received rehabilitation alone did not. The present thesis suggests that transcranial direct current stimulation may be a viable adjunct therapy to increase the efficacy of physical rehabilitation with regard to post-stroke motor outcomes. Interhemishperic coherence between homotopic neuronal populations may represent a biomarker of genuine motor recovery after stroke. / ix, 75 leaves : col. ill. ; 29 cm

M.A. / "Stroke is one of the leading causes of death and disability in all races in South Africa" (Fritz & Penn, 1992, p 1). It has devastating effects, and may impact on every aspect of the person's functioning. Research shows that depression is common after stroke, becoming more of a problem with time, and having a greater effect on quality of life than the actual disability (Lezak, 1995). Despite such evidence psychologists have played a very limited role in the rehabilitation of this group. Those with communication problems especially have been excluded from research and therapy, which usually require competence with language to be successful. This study attempts to find an alternative method of research and therapy in order to include this group. Following the model of learned helplessness (Seligman, in, Bleiberg, 1986), it was proposed that the unavoidable, inescapable effects of stroke lead to feelings of helplessness, which are also impossible to escape, and the person soon looses the motivation to attempt to control the situation. This then leads to depression. A method of therapy which breaks this cycle, and allows for the person to experience how their actions do have an effect on their lives is needed. In addition to this, an alternative means of self expression for those with communication difficulties needs to be provided. Art therapy was found to address the problems presented by this group (Dailey, 1984). It has proved useful with other populations that have not been able to benefit from traditional psychotherapy. It becomes an alternative means of self expression for those whose communication ability is compromised. It is accessible to most people, as it only requires the ability to make marks on paper. A theme centred, art therapy approach was therefore chosen for the study. The aims of the study were; to create a therapeutic milieu which allowed for self expression, specifically the expression of emotions, which included all the participants; to investigate the effects of introducing an opportunity for self expression on self concept and group process; and to look at the themes which emerge from the art. The participants were members of a pre-existing support group for stroke survivors. A quasiexperimental design was used. The Draw a Person Test, was administered pre and post intervention. Additional information was gathered using the Beck's Depression Inventory and a demographic questionnaire. This study uses a qualitative method, which includes information regarding the researcher's experience, and is interpreted from the researcher's perspective. It was found that art therapy had a positive effect on self concept. It influenced group process, as participants who were previously marginalised became more central. Numerous themes emerged, some which were specific to individuals, but others that were of relevance to the group as a whole. It proved rewarding for the researcher, both as a therapist and in terms of her relationship with her father who is a stroke survivor with aphasia. Art therapy therefore seems to be a useful tool to be used with this group that has traditionally been excluded from therapy and research. It is suggested that further research would be useful, and suggestions regarding future research are discussed.