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A Collie

Publications and source records attributed to A Collie.

24 records · Page 2Linked to original sources
PubMed2001

Computerised cognitive assessment of concussed Australian Rules footballers.

BACKGROUND: "Paper and pencil" neuropsychological tests play an important role in the management of sports related concussions. They provide objective information on the athlete's cognitive function and thus facilitate decisions on safe return to sport. It has been proposed that computerised cognitive tests have many advantages over such conventional tests, but their role in this domain is yet to be established. OBJECTIVES: To measure cognitive impairment after concussion in a case series of concussed Australian Rules footballers, using both computerised and paper and pencil neuropsychological tests. To investigate the role of computerised cognitive tests in the assessment and follow up of sports related concussions. METHODS: Baseline measures on the Digit Symbol Substitution Test (DSST), Trail Making Test-Part B (TMT), and a simple reaction time (SRT) test from a computerised cognitive test battery (CogState) were obtained in 240 players. Tests were repeated in players who had sustained a concussive injury. A group of non-injured players were used as matched controls. RESULTS: Six concussions were observed over a period of nine weeks. At the follow up, DSST and TMT scores did not significantly differ from baseline scores in both control and concussed groups. However, analysis of the SRT data showed an increase in response variability and latency after concussion in the injured athletes. This was in contrast with a decrease in response variability and no change in latency on follow up of the control players (p<0.02). CONCLUSION: Increased variability in response time may be an important cognitive deficit after concussion. This has implications for consistency of an athlete's performance after injury, as well as for tests used in clinical assessment and follow up of head injuries.

Adolescent↗
PubMed2000

The neuropsychology of preclinical Alzheimer's disease and mild cognitive impairment.

Subjects in the preclinical stages of Alzheimer's disease (AD) typically record neuropsychological performance between that of healthy older individuals and demented patients. More specifically, deficits on measures of verbal episodic memory are commonly reported in these patients, while other cognitive functions (e.g. language, praxis and executive function) seem to be spared. A similar neuropsychological profile is observed in elderly subjects with mild cognitive impairment (MCI), a disorder that is attracting increasing research interest. Evidence from lesion and functional imaging studies, as well as volumetric imaging in probable AD and MCI patients, suggests that the cognitive deficits observed in these disorders may be related to medial temporal lobe dysfunction. An issue currently under investigation is whether MCI represents the preclinical stages of AD or a distinct and static cognitive aetiology. In an attempt to address this issue, present investigations are adopting a convergent approach to the detection of preclinical AD, where multiple risk factors are considered when making a diagnosis.

Alzheimer Disease↗
PubMed2000

Spatiotemporal distribution of facilitation and inhibition of return arising from the reflexive orienting of covert attention.

Currently, there is debate regarding both the spatial and temporal relationship between facilitation and inhibition of return (IOR) components of attention, as observed on the covert orienting of visual attention task (COVAT). These issues were addressed in a series of experiments where the spatial and temporal relationships between cue and target were manipulated. Facilitation occurred only when the stimulus onset asynchrony (SOA) was short and there was temporal overlap between cue and target. IOR occurred only when SOA was long and there was no temporal overlap between cue and target. Facilitation encompassed the cued location and all locations between the cue and fixation, whereas IOR arose for the entire cued hemifield. These findings suggest that the facilitation and IOR found on COVATs that use noninformative peripheral cues are separable and stimulus-driven processes.

Adult↗
PubMed1999

Norms and the effects of demographic variables on a neuropsychological battery for use in healthy ageing Australian populations.

OBJECTIVE: The current study examined the performance of a healthy ageing population on the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological test battery in order to determine norms for use in an Australian setting. The effects of age, education, gender and mood on cognitive performance in healthy older individuals were also explored. METHOD: The CERAD neuropsychological battery was administered to a sample of healthy elderly subjects (n = 243). Subjects also completed an anxiety inventory and a depression scale. Means and standard deviations of different age, gender and education groups are reported as normative data. A Principal Components Analysis (PCA) was also calculated. Linear regression was applied to the five factors extracted from the PCA using age, education, gender and mood as independent variables. RESULTS: All recorded means were within 1 SD of those reported in the original CERAD normative study. Five factors that loaded on measures of memory and learning, language, praxis and executive function were extracted. The independent variables age, education and gender all had significant effects on cognitive performance. However, mood had no such effect. CONCLUSIONS: Risk factors for cognitive decline indicated by the CERAD battery include age, education and gender. Anxiety and depression are not associated with CERAD cognitive performance. The CERAD battery is a valid and reliable neuropsychological tool that may assist in the detection and diagnosis of Alzheimer's disease in Australian populations.

Adult↗
PubMed1989

The Tuberculosis Control Programme, 1985-1986. Results of the data-capturing programme instituted by the Department of National Health and Population Development and the Standing Committee on Epidemiology of the Regional Health Organisation for southern Africa.

The Tuberculosis Control Programme during 1985 and 1986 in the seven health regions of the RSA is described. This information has not previously been available. In 1986 the total tuberculosis case load exceeded 90,000. Of about 56,000 patients in whom the outcome was known, nearly 44,000 were discharged from the programme cured, about 9,500 absconded from therapy and 3,000 died. About 222,000 suspects or contacts of cases were investigated. Analysis of the data by health region revealed regional differences of prevalence rates, predominance of inpatient or outpatient treatment, cure rates, the ratio of new tuberculosis suspects or contacts found for every new confirmed case, and the cost of the programme per case and per capita of the population. Although these data must be interpreted cautiously, it is hoped that they will be valuable to all health workers fighting this major infectious disease in South Africa.

Data Collection↗