Melbourne School of Psychological Sciences - Theses
Permanent URI for this collection
Search Results
1 - 2 of 2
-
ItemCognitive and psychosocial functioning in genetic generalised epilepsy( 2017)Genetic generalised epilepsies (GGE) are a common, but under-studied cluster of epileptic syndromes of predominantly child and adolescent onset. The primary syndromes of GGE are childhood absence epilepsy (CAE), juvenile absence epilepsy(JAE), juvenile myoclonic epilepsy (JME), and genetic generalised epilepsy with generalised tonic-clonic seizures only (GTSCO). Important questions remain regarding: the degree of cognitive and psychopathological comorbidity, particularly in adults and in syndromes other than JME; effects of the disease on cognitive function; and psychopathology and psychosocial wellbeing in these patient groups. This thesis aimed to provide a detailed and quantitative description of cognitive function and psychopathology in GGE, assess the impact of contributing factors including subclinical epileptiform discharges on cognitive and psychopathology outcomes, and to evaluate the relationship between psychopathology and cognition. Methods employed include narrative systematic review, quantitative meta-analysis, and prospective assessment of cognitive and psychosocial functioning of a relatively large sample of people with GGE. Results indicated mild to moderately large reductions across most cognitive factors relative to that of healthy control participants and age-based normative data, with a relative weakness in long-term retrieval and memory function. Short-term memory function was not reduced relative to age-based normative data. Overall cognitive ability and memory function was negatively associated with total duration of epileptiform discharges during a 24-hour period. Approximately 50% of the sample reported elevated symptoms on a measure of psychopathology spanning six symptom types, with depression and anxiety the most common amongst these. Collectively, these findings highlight the need for increased awareness, screening and the provision of services for psychological comorbidities for people with GGE.
-
ItemNeurocognitive and psychiatric markers of network disease in epilepsy( 2015)People with epilepsy frequently experience debilitating memory and mood difficulties. Autobiographic memory impairments are a vulnerability factor for developing and maintaining unipolar depression in the psychiatric population, yet despite the wealth of research examining cognition and behaviour in epilepsy, the links between them remain unclear. This thesis aimed to profile the autobiographic memory and mood function of patients with focal epilepsy relative to healthy controls, and characterise how these functions may be interlinked. Three behavioural studies were conducted to achieve these objectives. Participants were prospectively recruited from the Comprehensive Epilepsy Programme at Austin Health, Melbourne, between 2010-2014. The cognitive and psychiatric functioning of 85 adults with chronic focal epilepsy was compared to that of 72 sociodemographically-matched controls largely recruited from the patients’ families (N=157). Gold-standard psychometric measures assessed depressive symptoms and cognitive function. Study One was an initial qualitative exploration of the relationships between cognitive impairment and depression in a form of focal epilepsy not typically linked to memory disorder, to assess the effects of seizures and pathology on those functions. A well-characterised case series of nine patients with frontal lobe epilepsy (FLE) was contrasted to 24 matched controls. Results suggested that FLE can selectively interrupt the integrity of the autobiographic memory/cognitive control networks versus the affective network. Study Two aimed to quantitatively delineate the effects of seizure chronicity on impaired autobiographic memory in a large cohort of patients (n=85) relative to healthy controls (n=72), and the potential links between poor autobiographic recall and mood. This revealed that chronic seizures beginning in childhood dysregulate cognition-related networks important for autobiographic recall, while autobiographic memory impairments in patients with a more recent disease onset are largely linked to depressive symptoms, perhaps reflecting maladaptive psychological adjustment to the onset of epilepsy as an adult. Together, the first two studies show that autobiographic memory difficulties are only related to depression in certain epilepsy syndromes. Finally, Study Three comprised a data-driven investigation into the existence of a cognitive phenotype of depression in epilepsy. Results showed that of the 21 (25%) patients currently meeting criteria for a formal depressive disorder, 15 (71%) had a ‘Cognitive’ phenotype of the disorder, while six (29%) presented with a ‘Somatic’ phenotype. These findings are congruent with phenotypes of depression found in other populations, and suggest that different presentations of depression in epilepsy may uniquely index dysregulation of selected brain networks. Moreover the lack of seizure-related correlates to the Cognitive phenotype discounts the widespread assumption that cognitive and affective network dysfunction in epilepsy is a side-effect of seizures. The results of this thesis suggest that epilepsy can selectively disrupt large-scale brain networks important to cognition and affect, and that behavioural disturbances in people with epilepsy may be primary manifestations of the network disease.