Tommy Davis - Academia.edu (original) (raw)
Papers by Tommy Davis
Early detection of Alzheimer's disease (AD) and related dementias in the elderly is critical ... more Early detection of Alzheimer's disease (AD) and related dementias in the elderly is critical for improving treatment methods and is a necessary component for improving public health interventions. One of the earliest and most common behavioral syndromes of AD is apathy and is associated with executive dysfunction. Apathy in AD is often misdiagnosed as depression due to an overlap in symptoms. Studies that have found depression to be associated with executive dysfunction have not always controlled for the presence of apathy. The Geriatric Depression Scale (GDS) is a widely used instrument designed to assess depression in the elderly. This study utilized the GDS and a set of standard neuropsychological instruments to investigate the relationship between apathy, depression, and executive functions in individuals with AD and related dementias. The first objective of this study was to determine if apathy has a greater impact on executive functions compared to depression in AD and rel...
Factor Structure of the Geriatric Depression Scale in Cognitively Impaired Older Adults
Clinical Gerontologist, 2009
This study explores the factor structure of the 30-item Geriatric Depression Scale (GDS) obtained... more This study explores the factor structure of the 30-item Geriatric Depression Scale (GDS) obtained from a sample of elderly adults who were diagnosed with some level of cognitive impairment. Principle components analysis obtained a four-factor solution utilizing all 30 GDS items. The derived factors were labeled Dysphoria, Meaninglessness, Apathy, and Cognitive Impairment. Although differences in factor structure were noted, some
UMI, ProQuest ® Dissertations & Theses. The world's most comprehensive collection of dissert... more UMI, ProQuest ® Dissertations & Theses. The world's most comprehensive collection of dissertations and theses. Learn more... ProQuest, The effectiveness of the Geriatric Depression Scale to distinguish apathy from depression in Alzheimer's disease and related dementias. ...
Archives of Neurology, 2010
To determine the spatial distribution of cortical and subcortical volume loss in patients with di... more To determine the spatial distribution of cortical and subcortical volume loss in patients with diffuse traumatic axonal injury and to assess the relationship between regional atrophy and functional outcome. Design: Prospective imaging study. Longitudinal changes in global and regional brain volumes were assessed using high-resolution magnetic resonance imaging-based morphometric analysis. Setting: Inpatient traumatic brain injury unit. Patients or Other Participants: Twenty-five patients with diffuse traumatic axonal injury and 22 ageand sex-matched controls. Main Outcome Measure: Changes in global and regional brain volumes between initial and follow-up magnetic resonance imaging were used to assess the spatial distribution of posttraumatic volume loss. The Glasgow Outcome Scale-Extended score was the primary measure of functional outcome. Results: Patients underwent substantial global atrophy with mean whole-brain parenchymal volume loss of 4.5% (95% confidence interval, 2.7%-6.3%). Decreases in volume (at a false discovery rate of 0.05) were seen in several brain regions including the amygdala, hippocampus, thalamus, corpus callosum, putamen, precuneus, postcentral gyrus, paracentral lobule, and parietal and frontal cortices, while other regions such as the caudate and inferior temporal cortex were relatively resistant to atrophy. Loss of whole-brain parenchymal volume was predictive of long-term disability, as was atrophy of particular brain regions including the inferior parietal cortex, pars orbitalis, pericalcarine cortex, and supramarginal gyrus. Conclusion: Traumatic axonal injury leads to substantial posttraumatic atrophy that is regionally selective rather than diffuse, and volume loss in certain regions may have prognostic value for functional recovery.
Alzheimer's & Dementia, 2008
associated with the subject of their language production. Besides, they showed vocabulary-finding... more associated with the subject of their language production. Besides, they showed vocabulary-finding difficulties. Although they have progressive lexical damage, their communication ability is not severely damaged and they show a lot of cultural and ideological lexical aspects in their discourses. Conclusions: Our results obtained from Alzheimer's disease patients seem to support the role of lexical deficits and they are mostly produced with paraphrased expressions related to information in their discourse. Many times they use a lot of words that have strong cultural and ideological meanings. Showing the uses of lexical aspects of the discourses in AD will not only contribute to our understanding of the language deficits of AD but will also offer ways of improving communication between AD patients and caregivers.
Archives of Neurology, 2010
To determine the spatial distribution of cortical and subcortical volume loss in patients with di... more To determine the spatial distribution of cortical and subcortical volume loss in patients with diffuse traumatic axonal injury and to assess the relationship between regional atrophy and functional outcome. Design: Prospective imaging study. Longitudinal changes in global and regional brain volumes were assessed using high-resolution magnetic resonance imaging-based morphometric analysis. Setting: Inpatient traumatic brain injury unit. Patients or Other Participants: Twenty-five patients with diffuse traumatic axonal injury and 22 ageand sex-matched controls. Main Outcome Measure: Changes in global and regional brain volumes between initial and follow-up magnetic resonance imaging were used to assess the spatial distribution of posttraumatic volume loss. The Glasgow Outcome Scale-Extended score was the primary measure of functional outcome. Results: Patients underwent substantial global atrophy with mean whole-brain parenchymal volume loss of 4.5% (95% confidence interval, 2.7%-6.3%). Decreases in volume (at a false discovery rate of 0.05) were seen in several brain regions including the amygdala, hippocampus, thalamus, corpus callosum, putamen, precuneus, postcentral gyrus, paracentral lobule, and parietal and frontal cortices, while other regions such as the caudate and inferior temporal cortex were relatively resistant to atrophy. Loss of whole-brain parenchymal volume was predictive of long-term disability, as was atrophy of particular brain regions including the inferior parietal cortex, pars orbitalis, pericalcarine cortex, and supramarginal gyrus. Conclusion: Traumatic axonal injury leads to substantial posttraumatic atrophy that is regionally selective rather than diffuse, and volume loss in certain regions may have prognostic value for functional recovery.
Factor Structure of the Geriatric Depression Scale in Cognitively Impaired Older Adults
Clinical Gerontologist, 2009
This study explores the factor structure of the 30-item Geriatric Depression Scale (GDS) obtained... more This study explores the factor structure of the 30-item Geriatric Depression Scale (GDS) obtained from a sample of elderly adults who were diagnosed with some level of cognitive impairment. Principle components analysis obtained a four-factor solution utilizing all 30 GDS items. The derived factors were labeled Dysphoria, Meaninglessness, Apathy, and Cognitive Impairment. Although differences in factor structure were noted, some
Early detection of Alzheimer's disease (AD) and related dementias in the elderly is critical ... more Early detection of Alzheimer's disease (AD) and related dementias in the elderly is critical for improving treatment methods and is a necessary component for improving public health interventions. One of the earliest and most common behavioral syndromes of AD is apathy and is associated with executive dysfunction. Apathy in AD is often misdiagnosed as depression due to an overlap in symptoms. Studies that have found depression to be associated with executive dysfunction have not always controlled for the presence of apathy. The Geriatric Depression Scale (GDS) is a widely used instrument designed to assess depression in the elderly. This study utilized the GDS and a set of standard neuropsychological instruments to investigate the relationship between apathy, depression, and executive functions in individuals with AD and related dementias. The first objective of this study was to determine if apathy has a greater impact on executive functions compared to depression in AD and rel...
Factor Structure of the Geriatric Depression Scale in Cognitively Impaired Older Adults
Clinical Gerontologist, 2009
This study explores the factor structure of the 30-item Geriatric Depression Scale (GDS) obtained... more This study explores the factor structure of the 30-item Geriatric Depression Scale (GDS) obtained from a sample of elderly adults who were diagnosed with some level of cognitive impairment. Principle components analysis obtained a four-factor solution utilizing all 30 GDS items. The derived factors were labeled Dysphoria, Meaninglessness, Apathy, and Cognitive Impairment. Although differences in factor structure were noted, some
UMI, ProQuest ® Dissertations & Theses. The world's most comprehensive collection of dissert... more UMI, ProQuest ® Dissertations & Theses. The world's most comprehensive collection of dissertations and theses. Learn more... ProQuest, The effectiveness of the Geriatric Depression Scale to distinguish apathy from depression in Alzheimer's disease and related dementias. ...
Archives of Neurology, 2010
To determine the spatial distribution of cortical and subcortical volume loss in patients with di... more To determine the spatial distribution of cortical and subcortical volume loss in patients with diffuse traumatic axonal injury and to assess the relationship between regional atrophy and functional outcome. Design: Prospective imaging study. Longitudinal changes in global and regional brain volumes were assessed using high-resolution magnetic resonance imaging-based morphometric analysis. Setting: Inpatient traumatic brain injury unit. Patients or Other Participants: Twenty-five patients with diffuse traumatic axonal injury and 22 ageand sex-matched controls. Main Outcome Measure: Changes in global and regional brain volumes between initial and follow-up magnetic resonance imaging were used to assess the spatial distribution of posttraumatic volume loss. The Glasgow Outcome Scale-Extended score was the primary measure of functional outcome. Results: Patients underwent substantial global atrophy with mean whole-brain parenchymal volume loss of 4.5% (95% confidence interval, 2.7%-6.3%). Decreases in volume (at a false discovery rate of 0.05) were seen in several brain regions including the amygdala, hippocampus, thalamus, corpus callosum, putamen, precuneus, postcentral gyrus, paracentral lobule, and parietal and frontal cortices, while other regions such as the caudate and inferior temporal cortex were relatively resistant to atrophy. Loss of whole-brain parenchymal volume was predictive of long-term disability, as was atrophy of particular brain regions including the inferior parietal cortex, pars orbitalis, pericalcarine cortex, and supramarginal gyrus. Conclusion: Traumatic axonal injury leads to substantial posttraumatic atrophy that is regionally selective rather than diffuse, and volume loss in certain regions may have prognostic value for functional recovery.
Alzheimer's & Dementia, 2008
associated with the subject of their language production. Besides, they showed vocabulary-finding... more associated with the subject of their language production. Besides, they showed vocabulary-finding difficulties. Although they have progressive lexical damage, their communication ability is not severely damaged and they show a lot of cultural and ideological lexical aspects in their discourses. Conclusions: Our results obtained from Alzheimer's disease patients seem to support the role of lexical deficits and they are mostly produced with paraphrased expressions related to information in their discourse. Many times they use a lot of words that have strong cultural and ideological meanings. Showing the uses of lexical aspects of the discourses in AD will not only contribute to our understanding of the language deficits of AD but will also offer ways of improving communication between AD patients and caregivers.
Archives of Neurology, 2010
To determine the spatial distribution of cortical and subcortical volume loss in patients with di... more To determine the spatial distribution of cortical and subcortical volume loss in patients with diffuse traumatic axonal injury and to assess the relationship between regional atrophy and functional outcome. Design: Prospective imaging study. Longitudinal changes in global and regional brain volumes were assessed using high-resolution magnetic resonance imaging-based morphometric analysis. Setting: Inpatient traumatic brain injury unit. Patients or Other Participants: Twenty-five patients with diffuse traumatic axonal injury and 22 ageand sex-matched controls. Main Outcome Measure: Changes in global and regional brain volumes between initial and follow-up magnetic resonance imaging were used to assess the spatial distribution of posttraumatic volume loss. The Glasgow Outcome Scale-Extended score was the primary measure of functional outcome. Results: Patients underwent substantial global atrophy with mean whole-brain parenchymal volume loss of 4.5% (95% confidence interval, 2.7%-6.3%). Decreases in volume (at a false discovery rate of 0.05) were seen in several brain regions including the amygdala, hippocampus, thalamus, corpus callosum, putamen, precuneus, postcentral gyrus, paracentral lobule, and parietal and frontal cortices, while other regions such as the caudate and inferior temporal cortex were relatively resistant to atrophy. Loss of whole-brain parenchymal volume was predictive of long-term disability, as was atrophy of particular brain regions including the inferior parietal cortex, pars orbitalis, pericalcarine cortex, and supramarginal gyrus. Conclusion: Traumatic axonal injury leads to substantial posttraumatic atrophy that is regionally selective rather than diffuse, and volume loss in certain regions may have prognostic value for functional recovery.
Factor Structure of the Geriatric Depression Scale in Cognitively Impaired Older Adults
Clinical Gerontologist, 2009
This study explores the factor structure of the 30-item Geriatric Depression Scale (GDS) obtained... more This study explores the factor structure of the 30-item Geriatric Depression Scale (GDS) obtained from a sample of elderly adults who were diagnosed with some level of cognitive impairment. Principle components analysis obtained a four-factor solution utilizing all 30 GDS items. The derived factors were labeled Dysphoria, Meaninglessness, Apathy, and Cognitive Impairment. Although differences in factor structure were noted, some