Syndromes and seizures: case studies in cognition and mental disorders of adults with epilepsy

Ballini, Evangelina Evelyn (2013) Syndromes and seizures: case studies in cognition and mental disorders of adults with epilepsy. Masters (Research) thesis, James Cook University.

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Abstract

The study's general purpose was to examine cognitive functioning and mental disorders associated with syndromes or seizures of individuals with different epilepsies. More specifically, the aim was to investigate the cognitive and psychosocial profile of individuals with a history of prolonged seizures (status epilepticus). Neuropsychological assessment included cognitive tasks, test batteries and three self-rated questionnaires on psychopathology. Case studies included absence status (ASE), complex partial status (CPSE), generalized convulsive status (GCSE) temporal lobe epilepsy (TLE), and idiopathic generalized epilepsy (IGE). Most of the 24 adults, 18 to 65 years, had epilepsy of a cryptogenic or genetic aetiology. Individuals were compared to an IGE comparison group utilizing computational techniques designed for single case analyses. Overall, the findings from the series of case studies in IGE concurred with the traditional view that IGE does not generally impact on cognitive function. Against this background, two photosensitive cases with perioral myoclonia and eyelid myoclonia with absences had severe impairments of attentional control and memory systems. Those IGE individuals with single or no reflex components had very mild dysfunction (if any at all).

At best, the assumption that TLE impacts on localized memory deficits which lateralize according to material-specificity principles was only partially upheld. An organization into three classes of deficits and strengths emerged from the assessment results, based loosely on seizure types and the presence of structural abnormalities. Adaptability of cognitive skills to alleviate possible memory problems seems to have been possible through an individual's reserve strengths; less possible when attention responses and fluency errors reflected a quality of rigidity (those cases with secondarily generalized seizures); or when generalized impairment (executive functions, language and verbal memory) was associated with compromised brain reserve such as hippocampal sclerosis. It was concluded that these three classes might be interpreted as cognitive phenotypes of TLE.

The SE results showed that not all prolonged seizures are associated with long-standing cognitive deficits and a poor prognosis. Overall, the GCSE participants did not demonstrate the most severe cognitive impairments as predicted, most having transient cognitive impairment which resolved over time. More widespread and longer-lasting deficits were reported in the two CPSE cases with secondarily generalized seizures and histories of polysubstance abuse.

Attentional impairments were ubiquitous throughout the SE performance scores (particularly divided attention and vigilance) in the SE participants, followed by verbal executive abilities, then language and memory. Four SE cases showed a decline from pre-morbid levels of intelligence which might have been associated with the duration of their prolonged seizures (> 45 minutes). The number of GCSE seizures was negatively associated with current estimated I.Q. and delayed verbal memory. The presence of severe deficits and higher seizure numbers seemed associated with SE participants' healthy or unhealthy life-styles pre- and post-onset of prolonged seizures, rather than attributable directly to SE seizure-type impact. The study results concur with the view that SE seizures are more likely to occur in an abnormal brain with little neuroprotection.

The GCSE and TLE participants differed in the co-morbid relations underlying their psychopathology and epilepsy condition. The TLE participants' epilepsy and mood disorders may have been linked by their common origins in the temporal lobes, a product of disrupted activity in the limbic system. In contrast, the GCSE participants' lack of awareness of depression and emotional-social dysfunction was probably a component of their epilepsy syndrome and also a complication of prolonged seizures. All three questionnaires used in this study (ESDQ, EFQ and DASS) involved self-rated responses. Self-rating scores for everyday memory and concentration difficulties were compared to formal tests of attention and memory, perceived abnormality was compared to the participants' descriptions of their actual life circumstances and these were then corroborated (or not) by their partners. Results were interpreted as indicating how participants arrived at their perceptions of abnormality rather than giving an accurate estimate of emotional status. The most interesting finding for the psychopathology investigation was the contrast (found across several analyses) between a lack of understanding or insight (TLE cases) and a lack of self-awareness (GCSE cases).

This study was carried out in the theoretical context of the ILAE's previous classification and diagnostic systems, which have recently been up-dated to encompass the influx of new knowledge from neuroimaging and genetics research. Their adequacy for atypical, sometimes rare, single cases was considered, and whether each profile contradicted or conformed to traditional assumptions about functioning in epilepsy. Some cases did not uphold predictions about cognition in IGE, TLE and SE, highlighting exceptions to the old black-or-white classification dichotomies. Participants' disorders might be better conceptualized as "system epilepsies" rather than the syndromes of signs and symptoms which constituted the 1989 ILAE classification systems.

Item ID: 5497
Item Type: Thesis (Masters (Research))
Keywords: cognition; cognitive deficits; cognitive function; epilepsy; fits; mental impairment; neuropsychology; seizures; syndromes
Date Deposited: 05 Aug 2015 05:54
FoR Codes: 17 PSYCHOLOGY AND COGNITIVE SCIENCES > 1701 Psychology > 170106 Health, Clinical and Counselling Psychology @ 100%
SEO Codes: 92 HEALTH > 9201 Clinical Health (Organs, Diseases and Abnormal Conditions) > 920111 Nervous System and Disorders @ 100%
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