Mitochondrial Diseases (MD) are disorders of function in cellular oxidative phosphorylation caused by diverse nuclear DNA and mtDNA mutations and seen in 1/5,000 births. The purpose of this study was to examine relationships across medical indices, biochemical measures, and neurobehavioral functioning in children with MD. Findings from Western Blot, Native Gels, High Resolution Respirometry, and the Nijmegen diagnostic criteria were assessed in relation to children’s processing speed and attention, based on the prediction that impaired functioning of proteins, complexes, and cellular respiration, that are critical in ATP production, will impact neurodevelopment and related neuropsychological processes in children with MD. Twenty-five children (ages 4-13) were administered subtests from the DAS-II and NEPSY-II. Results from multiple regression analyses suggest that processing speed and attention deficits may be markers of abnormal protein expression that interferes with the production of ATP in the oxidative phosphorylation process; implications for future research are presented.

Thesis--University of Oklahoma. / Includes bibliographical references (leaves 51-58).

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009. / Title from title screen (site viewed January 5, 2010). PDF text: v, 187 p. : ill. ; 807 K. UMI publication number: AAT 3360289. Includes bibliographical references. Also available in microfilm and microfiche formats.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.

Executive functions impact everyday functioning. An individual’s ability to adapt to and navigate their physical and social environments is largely determined by the ability to organize oneself, to plan and to coordinate activities. Despite the wide variety of cognitive tests that assess various aspects of executive function, there has been little work to validate the use of these measures in predicting real world functioning (Sbordone, Seyranian, & Ruff, 2000), particularly in children where characterization of executive function is less specified. Evaluating the ecological validity of neuropsychological tests has become an increasingly important topic over the past decade (Chaytor & Schmitter- Edgecombe, 2003). Ecologically valid assessments of executive function and attentional deficits provide insight into deficits related to the child’s everyday adaptive functioning, which can assist in identifying targets for interventions. Although many performance based measures and caregiver behavior checklists exist for assessing a wide range of behaviors and adaptive functioning skills in children, comprehensive measures of executive functions are relatively new and largely unexplored. The purpose of this study was to investigate and to define better the relationship between attention and corresponding behaviors that represent executive functions and social/adaptive functioning. More specifically, this study sought to explore the correlation between ratings of varying subcomponents of attention (e.g., selective attention, sustained attention, and attentional control/switching), executive function behaviors, and ratings of social/adaptive functioning. Additionally, gender considerations were examined with aims to determine how this factor may affect the degree of relationship between the proposed variables.  Results of multiple regression and correlational analyses revealed the ability of child attentional performance to predict executive function and social/adaptive functioning behaviors. As parent/caregiver and teacher ratings of executive function behaviors increased thus noting adept skills in these areas of functioning child performance on measures of selective attention, sustained attention, and attentional control/shifting were also reported to improve. Future research should continue to explore the construct validity, positive predictive power, negative predictive power, diagnostic sensitivity and specificity of the Test of Everyday Attention for Children (TEA-Ch).

Theory of mind is the ability to have mental states about mental states. Among theories concerning the structure and role of theory of mind is the view that theory of mind is the cognitive component of empathy. It is proposed that there is partial dissociation within theory of mind between emotional state representation and non-emotional state representation. In trying to test this hypothesis, an instrument was developed and implemented in a pilot study. Current theory of mind tests are reviewed and design features discussed in relation to the new hypothesis. The instrument aims to measure emotional and non-emotional state representation on separate subscales, as well as coding representations from emotional stories and non-emotional stories separately. The instrument was administered to 33 third level or higher students from the University of KwaZulu-Natal. Groups were chosen from science major (n = 9) and humanities major (n = 24) students. The findings fail to show the group performance patterns reported in literature, for example that humanities students tend to score higher in ToM tests than science students. A number of factors might contribute to the finding, but principally, low sample size and unequal general cognitive ability between groups are proposed as vital. Problems with the pilot study are identified and improvements suggested for subsequent testing. / Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2010.

Introduction-Physical activity can reduce the risk of contracting many of the 'diseases of the sedentary', such as coronary heart disease and cancer (Blair et al., 1996). Recognition of this protective effect has led to the development of many programmes designed to promote the benefit of participation in sport and physical exercise (Hillary Commission, 1993; Nicholl et aI., 1995). With participation in sport, especially contact sport, the risk for injuries increases, including injuries to the head and neck (Wilberger, 1993; Wekesa et al., 1996; Pettersen, 2002). Mild traumatic brain injuries (MTBI) or concussion as used interchangeably in the literature (Maroon et al., 2000; Wills & Leathem, 2001) are an important public health concern, due to the high incidence and frequently persisting symptomatology (Evans, 1992). Mild traumatic brain injury is defined as a complex patho-physiological process affecting the brain induced by traumatic biomechanical forces (Aubry et al., 2002; McCrory et al., 2004). A sub-concussive injury or very mild traumatic brain injury (vMTBI) may be defined as an apparent brain insult with insufficient force to cause hallmark symptoms of concussion (Jordan, 2000; Webbe & Bath, 2003). The high incidence of sport related head injuries in South Africa is alarming, although the prevalence thereof is unknown and difficult to assess, as the seemingly trivial injuries frequently remain unreported (Roux et al., 1987). This is especially applicable in sport where a milder form of head injury is common. This is cause for concern as cumulative head injuries traditionally regarded as trivial or 'minor' may result in players running the risk of increasingly negative consequences following repetitive 'minor' head injuries. In contact sport such as rugby, players are at great risk of sustaining repetitive mild traumatic brain injuries. The negative outcome following these repetitive minor head injuries has been demonstrated by numerous studies on boxers and other athletes exposed to repeated MTBI and vMTBI (McLatchie et aI., 1987). The incidence of vMTBI has not yet been researched in school rugby and this study is the first to report the incidence of vMTBI in a secondary school rugby team. Obiectives - The objectives of this study were to determine the incidence, the neuropsychological consequences and the effect on the academic performance of repeated mild (MTBI) and very mild traumatic brain injuries (vMTBI) in a secondary school rugby team during one playing season. Methods - A cohort of 35 secondary school male rugby players divided into a vMTBI (group 1) (n=26) and a MTBI (group 2) (n=9) from a local secondary school's first and second team, was followed for a full competitive season by a trained Biokineticist, who was present at all the games and contact sessions played. All vMTBI and MTBI and the severity of these injuries were documented. A control (group 3) that consisted of 10 secondary school non-rugby players were compared with the vMTBI and MTBI groups. The incidence of repeated MTBI and vMTBI in a secondary school rugby team were gathered by questionnaires and observation next to the field by a trained Biokineticist. Pre-season and post-season neuropsychological tests were conducted on the research groups and the control group. The neuropsychological tests that were conducted on the three groups were the Colour Trial Test 1 and 2 (CTT 1 + 2), the Symbol Digit Modalities Test (SDMT), the Wechsler Memory Scale-Revised (WMS-R) and the Standardised Assessment of Concussion (SAC). After each match played throughout the season the research group also completed a SAC test. The academic results of the final examination (year 1) of the year of the specific rugby season were obtained, as well as the academic results of the final examination of the preceding two years (year 2 and 3). The programme STATISTICA (version 7.0, Stat soft, Tulsa, OK) was used to analyse the data. Descriptive statistics, one-way ANOVA's, two-way repeated measures ANOVA's, Post-hoc Tuckey HSD analysis and Pearson's product moment correlation were used for all the statistical analyses. Results - This study of a secondary school rugby team has shown 726 vMTBI's and 18 MTBI's throughout one rugby season. This relates to 1951 vMTBI's per 1000 player hours and 48 MTBI's per 1000 player hours. Reductions in delayed memory (p=O.O1)from preseason to post-season in a group of players with repetitive vMTBI's during a single rugby season were found. This was the first evidence of possible neurocognitive deficits towards delayed memory in very mild traumatic brain injuries at secondary school level. Statistically significant (p<=0.05)results of the SAC test totals between both the vMTBI and MTBI groups were documented in the different games throughout the rugby season and compared with the baseline test. No statistically significant differences (p<=0.05) between the pre-season and post-season's scores of the SAC test totals were documented. A decrease in academic performance in the subject Afrikaans (year 1 compared with year 2) with a p-value of p=O.O17(group 1) and p=O.O16(group 2) respectively was found. Conclusion - The findings of this study indicate a high incidence of vMTBI in a cohort of secondary school rugby players in one season, a statistically significant reduction (p=O.O1 )in delayed memory of the vMTBI rugby players and a statistically significant decrease in academic performance p=O.O17 (group 1) and p=O.O16 (group 2) in the subject Afrikaans from year 1 to year 2 final examinations. / Thesis (Ph.D. (Human Movement Science))--North-West University, Potchefstroom Campus, 2006.

Alexandria Luria's approach to neuropsychological assessment and his theory of brain functioning have been exploited in order to develop a neuropsychological evaluation procedure for children which incorporates a conceptualization of brain-behaviour development. Luria's Neuropsychological Investigation for adults was administered to intact children aged eight to 14 years in order to ascertain which tasks were beyond their capabilities. These were then adapted or deleted. The adapted version of the protocol was then administered to a second group of intact children to determine that the proposed adaptations were appropriate. This process was guided by the results of a statistical analysis which revealed significant findings with respect to age, socioeconomic status, and task performance. A model of brain-behaviour development and interpretive protocol were devised. Together these provide a conceptual and interpretive framework for the battery. Developmental trends which emerged whilst developing Luria's Neuropsychological Investigation for Children (LNI-C) were consistent with the progressive development of successively more complex forms of information processing as depicted in this model. They were also in keeping with prominent developmental theories such as those of Piaget and Vygotsky. These trends revealed that children made most mistakes on adult LNI tasks involving abstract reasoning, the simultaneous synthesis of data, and complex goal-directed behaviour - all of which apparently reflect tertiary cortical zone functioning. Fewer mistakes were related to a lack of training and inability to process the same quantity of information as adults - difficulties which seemed related to secondary zone functioning. None of the mistakes made appeared to reflect subcortical or primary zone functioning. The LNI-C was applied to brain-damaged children who had had a CT scan in order to demonstrate its application and the hypothetico-deductive process of interpreting findings using the concepts of syndrome analysis and double dissociation. The LNI-C findings were consistent with the general pattern of symptoms Luria described for different brain disorders and lesion localities in children, although additional insight into the nature of the sequelae present was gained in each case. In early brain damage, the most frequent disturbances were a disruption in the role played by executive functions and the ability to process data simultaneously - both of which are associated with the tertiary zones of the brain. Furthermore, these disturbances appeared to be important factors underlying disturbances to language and educationally acquired skills. The qualitative, process-orientated nature of the LNI-C proved effective for identifying the factors underlying disturbances described in paramedical reports. These seemed to be the linchpins on which retraining should focus. It was argued that the CT scan was limited in its ability to identify the type of diffuse and/or multifocal brain pathology frequently found in children. The usefulness of the model of brain-behaviour ontogeny and interpretive protocol for diagnosis, understanding and predicting the developmental consequences of childhood brain pathology was demonstrated on the basis of nine brain disorders. Finally, areas of future research were highlighted by the study. / Thesis (Ph.D.)-University of Natal, Durban, 1989.

Normal ageing is associated with decline in visual, cognitive, and physical functioning, with concurrent increases in the incidence of chronic medical conditions, including cognitive disorders. Determining when age-related changes have adversely affected a person’s ability to drive safely is a complex task, particularly when cognitive disorders such as mild cognitive impairment and dementia are present. The aim of this research was to assess the utility of a number of off-road measures in predicting Pass and Fail outcomes for older drivers on a blinded on-road driving assessment with a driving specialist occupational therapist and a driving instructor, which is considered the ‘gold standard’ measure of driving ability. The off-road measures included standardized cognitive tests, computerized sensory-motor & cognitive tests, medical conditions, and personality measures. The research project comprised three studies. In Study 1 (Healthy Older Drivers study), 60 drivers with no diagnosed cognitive disorder (‘cognitively-unimpaired’), aged 70-84 years (mean age 76.7, 50% male), completed standard cognitive tests, computerized sensory-motor and cognitive tests (SMCTests™), and measures of personality. Results were used to form classification models for on-road assessment Pass and Fail outcome. Sixteen participants failed the on-road assessment. A backwards stepwise binary logistic regression model selected a measure of executive function and a computerized measure of visuomotor planning and coordination as the best predictors. Following leave-one-out cross-validation, this model was estimated to correctly predict 60% of an independent group of cognitively-unimpaired older drivers into on-road Pass and Fail groups. In Study 2 (Healthy Driver Follow-up study), 56 participants from the Healthy Older Drivers study were followed for 24 months using annual telephone interviews to assess driving behaviour, driving attitudes, medical conditions, and the occurrence of crashes and receipt of traffic offences. Official data regarding crashes and traffic offences were also obtained. The aim was to determine whether either the on-road Pass/Fail classification or the off-road measures could predict subsequent crashes and offences. Failing the on-road assessment was not associated with higher crash or offence rates and there were only two baseline measures that predicted crashes or offences (i.e., distance driven at baseline testing and, paradoxically, a lower error score on a measure of visuomotor planning and coordination). However, drivers who reported more distress associated with their medical condition(s) were more likely to have had a crash or offence at 24 months. The outcomes of the Healthy Older Drivers and Healthy Driver Follow-up studies suggest that there is little value in off-road or on-road assessment of cognitively-unimpaired older drivers due to the weak relationship with future negative driving outcomes. However, distress associated with medical conditions may be a useful measure. Study 3 (Dementia and Driving study) recruited a sample of 60 driving assessment centre referrals with mild cognitive impairment or Alzheimer’s dementia. These participants, aged 58-92 years (mean age 77.9, 60% male), performed a computerized battery of sensory-motor and cognitive tests and a formal blinded on-road driving assessment. A backwards stepwise binary logistic regression model selected measures of reaction time and movement speed of the upper limbs, visuomotor planning and coordination, and sustained attention. Following leave-one-out cross-validation, this model was estimated to correctly predict 68% of an independent group of drivers with mild cognitive impairment and Alzheimer’s dementia into on-road Pass and Fail groups. A subsample of 32 participants completed additional standard cognitive tests and provided information on medical conditions. A binary logistic regression model in this subsample was formed which selected measures of verbal fluency, the presence of heart disease, and a comprehensive cognitive screen. Following leave-one-out crossvalidation, this model would be expected to correctly classify 75% of an independent group of drivers with mild cognitive impairment and Alzheimer’s dementia into on-road Pass and Fail groups. The three measures in this model could be performed in around 35-50 min in a primary health setting. It is concluded that off-road and on-road assessment of older drivers with no diagnosis of cognitive or neurological disorder is an inaccurate and inefficient use of driving assessment resources, both for the prediction of on-road driving performance and for predicting future crashes and traffic offences. The Dementia and Driving study found a model comprising three measures that could be performed in a primary health setting with reasonable accuracy for correctly classifying people with mild cognitive impairment and Alzheimer’s dementia who go on to Pass and Fail an on-road driving assessment.

Veterans of the Iraqi and Afghanistan conflicts have frequently returned with injuries such as mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD). More recently, concern has been raised about the large number of returning soldiers who are diagnosed with both. Literature exists on the neuropsychological factors associated with either alone, however far less research has explored the effects when combined (PTSD+mTBI). With a sample of 206 OEF/OIF veterans, the current study employed neuropsychological and psychological measures to determine whether participants with PTSD+mTBI have poorer cognitive and psychological outcomes than participants with PTSD-o, mTBI-o, or veteran controls (VC), when groups are matched on IQ, education, and age. The PTSD+mTBI and mTBI-o groups exhibited very similar neuropsychology profiles, and both PTSD+mTBI and mTBI-o performed significantly (α=.01) worse than VC on executive functioning and processing speed measures. There were no significant differences between VC and PTSD-o on any notable neuropsychology measures. In contrast, on the psychological measures, the PTSD+mTBI and PTSD-o groups were identical to each other and more distressed than either mTBI-o or VC. These findings suggest there are lasting cognitive impairments following mTBI that are unique to the condition and cannot be attributed to known impairments associated with distress.