The objectives of this study were to (1) compare atrophy rates associated with normal aging and A... more The objectives of this study were to (1) compare atrophy rates associated with normal aging and Alzheimer disease (AD) using the semi-automated Boundary Shift Integral (BSI) method and manual tracing of the entorhinal cortex (ERC) and hippocampus and (2) calculate power of BSI vs. ERC and hippocampal volume changes for clinical trials in AD. We quantified whole brain and ventricular BSI atrophy rates and ERC and hippocampal atrophy rates from longitudinal MRI data in 20 AD patients and 22 age-matched healthy controls. All methods revealed significant brain atrophy in controls and AD patients. AD patients had approximately 2.5 times greater whole brain BSI atrophy rates and more than 5 times greater ERC and hippocampal atrophy rates than controls. ERC and hippocampal atrophy rates were higher in both groups than whole brain BSI atrophy rates, but lower than ventricular BSI atrophy rates. Effect size and power calculations suggest that ERC and hippocampal measurements may be more sens...
PURPOSE The diagnosis of Alzheimer’s disease currently requires neuropsychological assessment and... more PURPOSE The diagnosis of Alzheimer’s disease currently requires neuropsychological assessment and radiologic exclusion of structural abnormalities. There is increasing interest to identify individuals at risk for developing Alzheimer’s disease before irreversible neurodegeneration has occurred. Recent literature has suggested that temporal and parietal lobe volumes, particularly the hippocampus, are useful in discriminating those with Alzheimer’s disease from normal controls. The aim of this study is to determine whether automated volumetry of the temporal and parietal lobes from a baseline MRI predict those at risk for future memory decline among a multicenter cohort of elderly normals. METHOD AND MATERIALS The 191 participants (mean age = 76 +/- 5 years) were recruited through the Alzheimer’s Disease Neuroimaging Initiative (ADNI) as elderly controls and underwent a standardized baseline 1.5 T MRI scan, as well as neuropsychological assessment at baseline and after 2 years. No sig...
Alcohol-dependent individuals (ALC) have smaller hippocampi and poorer neurocognition than health... more Alcohol-dependent individuals (ALC) have smaller hippocampi and poorer neurocognition than healthy controls. Results from studies on the association between alcohol consumption and hippocampal volume have been mixed, suggesting that comorbid or premorbid factors (i.e., those present prior to the initiation of alcohol dependence) determine hippocampal volume in ALC.
This study was conducted to determine the relationship of frontal lobe cortical thickness and bas... more This study was conducted to determine the relationship of frontal lobe cortical thickness and basal ganglia volumes to measures of cognition in adults with sickle cell anemia (SCA). Participants included 120 adults with SCA with no history of neurologic dysfunction and 33 healthy controls (HCs). Participants were enrolled at 12 medical center sites, and raters were blinded to diagnostic group. We hypothesized that individuals with SCA would exhibit reductions in frontal lobe cortex thickness and reduced basal ganglia and thalamus volumes compared with HCs and that these structural brain abnormalities would be associated with measures of cognitive functioning (Wechsler Adult Intelligence Scale, 3rd edition). After adjusting for age, sex, education level, and intracranial volume, participants with SCA exhibited thinner frontal lobe cortex (t = -2.99, p = 0.003) and reduced basal ganglia and thalamus volumes compared with HCs (t = -3.95, p < 0.001). Reduced volume of the basal gangl...
The objectives of this study were to (1) compare atrophy rates associated with normal aging and A... more The objectives of this study were to (1) compare atrophy rates associated with normal aging and Alzheimer disease (AD) using the semi-automated Boundary Shift Integral (BSI) method and manual tracing of the entorhinal cortex (ERC) and hippocampus and (2) calculate power of BSI vs. ERC and hippocampal volume changes for clinical trials in AD. We quantified whole brain and ventricular BSI atrophy rates and ERC and hippocampal atrophy rates from longitudinal MRI data in 20 AD patients and 22 age-matched healthy controls. All methods revealed significant brain atrophy in controls and AD patients. AD patients had approximately 2.5 times greater whole brain BSI atrophy rates and more than 5 times greater ERC and hippocampal atrophy rates than controls. ERC and hippocampal atrophy rates were higher in both groups than whole brain BSI atrophy rates, but lower than ventricular BSI atrophy rates. Effect size and power calculations suggest that ERC and hippocampal measurements may be more sens...
T1 image,allowing assessment of volume, mean diffusivity (MD) and fractional anisotropy (FA) in t... more T1 image,allowing assessment of volume, mean diffusivity (MD) and fractional anisotropy (FA) in these regions. Longitudinal DT images were coregistered using tensor-based registration to examine FA, MD, axial and radial diffusivity (AD and RD) in the cingulum and fornix (ICBM-DTI-81 atlas). Whole brain and ventricular volumes were segmented using semi-automated techniques and atrophy/expansion rates calculated using the boundary shift integral. Linear regression, adjusting for age and gender, was used to assess differences in the imaging measures and their mean rates of change between MC and non-carrier groups. Results: The cohort comprised 12 mutation-negative participants and 17 MCs, six of whom reported symptoms at follow-up. MCs were on average 6.7 years younger than their parental age at symptom onset. MCs had smaller thalamic volumes bilaterally at baseline and follow-up, but there was little evidence for a difference in the rate of change over this interval. There was weak evidence for higher FA in bilateral thalamus and decreased AD in right cingulum at baseline and follow-up and lower right thalamic MD at baseline in MCs. When examined separately, MCs who became symptomatic had higher thalamic FA at follow-up than MCs who remained asymptomatic but both MC groups had smaller thalamic volumes than non-carriers. No significant group differences were evident for other imaging measures. Conclusions: Lower thalamic volumes and altered diffusivity were evident in FAD MCs compared to non-carriers at a stage when whole brain volumes and atrophy rates were similar. Thalamic FA in particular merits further investigation as a marker of early disease progression in larger FAD cohorts.
The goal of this study was to identify factors contributing to hippocampal atrophy rate (HAR) in ... more The goal of this study was to identify factors contributing to hippocampal atrophy rate (HAR) in clinically normal older adults (NC) and participants with mild cognitive impairment (MCI). Longitudinal HAR was measured on T1-weighted magnetic resonance imaging, and the contribution of age, gender, apolipoprotein E (ApoE) ε4 status, intracranial volume, white matter lesions, and β-amyloid (Aβ) levels to HAR was determined using linear regression. Age-related effects of HAR were compared in Aβ positive (Aβ+) and Aβ negative (Aβ-) participants. Age and Aβ levels had independent effects on HAR in NC, whereas gender, ApoE ε4 status, and Aβ levels were associated with HAR in MCI. In multivariable models, Aβ levels were associated with HAR in NC; ApoE ε4 and Aβ levels were associated with HAR in MCI. In MCI, age was a stronger predictor of HAR in Aβ- versus Aβ+ participants. HAR was higher in Aβ+ participants, but most of the HAR was because of factors other than Aβ status. Age-related effe...
The goal of this study was to assess the relationship between Ab deposition and white matter path... more The goal of this study was to assess the relationship between Ab deposition and white matter pathology (i.e., white matter hyperintensities, WMH) on microstructural integrity of the white matter. Fifty-seven participants (mean age: 7867 years) from an ongoing multi-site research program who spanned the spectrum of normal to mild cognitive impairment (Clinical dementia rating 0-0.5) and low to high risk factors for arteriosclerosis and WMH pathology (defined as WMH volume .0.5% total intracranial volume) were assessed with positron emission tomography (PET) with Pittsburg compound B (PiB) and magnetic resonance and diffusion tensor imaging (DTI). Multivariate analysis of covariance were used to investigate the relationship between Ab deposition and WMH pathology on fractional anisotropy (FA) from 9 tracts of interest (i.e., corona radiata, internal capsule, cingulum, parahippocampal white matter, corpus callosum, superior longitudinal, superior and inferior front-occipital fasciculi, and fornix). WMH pathology was associated with reduced FA in projection (i.e., internal capsule and corona radiate) and association (i.e., superior longitudinal, superior and inferior fronto-occipital fasciculi) fiber tracts. Ab deposition (i.e., PiB positivity) was associated with reduced FA in the fornix and splenium of the corpus callosum. There were interactions between PiB and WMH pathology in the internal capsule and parahippocampal white matter, where Ab deposition reduced FA more among subjects with WMH pathology than those without. However, accounting for apoE e4 genotype rendered these interactions insignificant. Although this finding suggests that apoE4 may increase amyloid deposition, both in the parenchyma (resulting in PiB positivity) and in blood vessels (resulting in amyloid angiopathy and WMH pathology), and that these two factors together may be associated with compromised white matter microstructural integrity in multiple brain regions, additional studies with a longitudinal design will be necessary to resolve this issue.
Our MR/MRS imaging studies of HIV, alcohol, ALS, dementia, and aging require experienced anatomis... more Our MR/MRS imaging studies of HIV, alcohol, ALS, dementia, and aging require experienced anatomists to delineate subcortical structures and lobar boundaries by hand. This requires rigorous training to ensure good intra-and inter-rater reliability, and an enormous investment of time. We are interested in developing an automated method for Identifying the boundaries of subcortical strnctnres and lobes. In brief, our approach is to identify the stmctnres of interest on a template or atlas brain, warp the template brain to a new subject's brain (i.e.. target brain) using the gray scale images, then to apply the resultant warp to the strncture identified on the template brain. This abstract describes our initial efforts at implementing and evaluating this approach.
The goal was to elucidate the time course of regional brain atrophy rates relative to age in cogn... more The goal was to elucidate the time course of regional brain atrophy rates relative to age in cognitively normal (CN) aging, mild cognitively impairment (MCI) and Alzheimer's disease (AD), without a-priori models for atrophy progression. Regional brain volumes from 147 CN subjects, 164 stable MCI, 93 MCI-to-AD converters and 111 AD patients, between 51 to 91 years old and who had repeated 1.5T magnetic resonance imaging (MRI) scans over 30 months, were analyzed. Relations between regional brain volume change and age were determined using generalized additive models, an established non-parametric concept for approximating nonlinear relations. Brain atrophy rates varied nonlinearly with age, predominantly in regions of the temporal lobe. Moreover, the atrophy rates of some regions leveled off with increasing age in control and stable MCI subjects whereas those rates progressed further in MCI-to-AD converters and AD patients. The approach has potential uses for early detection of AD and differentiation between stable and progressing MCI.
A previous study (1) suggested that individuals with Gulf War Illness (GWI) had reduced quantitie... more A previous study (1) suggested that individuals with Gulf War Illness (GWI) had reduced quantities of the neuronal marker N-acetyl aspartate (NAA) in the basal ganglia and pons. This study aimed to determine whether NAA is reduced in these regions and to investigate correlations with other possible causes of GWI, such as psychological response to stress in a large cohort of Gulf war veterans. Individuals underwent tests to determine their physical and psychological health and to identify veterans with (n=81) and without (n=97) GWI. When concentrations of NAA and ratios of NAA to creatine-and choline-containing metabolites were measured in the basal ganglia and pons, no significant differences were found between veterans with or without GWI, suggesting that GWI is not associated with reduced NAA in these regions. Veterans with GWI had significantly higher rates of Post Traumatic Stress Disorder (PTSD), supporting the idea that GWI symptoms are stress-related.
Context-Sickle cell anemia (SCA) is a chronic illness causing progressive deterioration in qualit... more Context-Sickle cell anemia (SCA) is a chronic illness causing progressive deterioration in quality of life. Brain dysfunction may be the most important and least studied problem affecting individuals with this disease.
Treatment with antiretroviral therapy (ART) has greatly reduced the incidence of dementia. The go... more Treatment with antiretroviral therapy (ART) has greatly reduced the incidence of dementia. The goal of this longitudinal study was to determine if there are ongoing macrostructural brain changes in human immunodeficiency virus-positive (HIV + ) individuals treated with ART. To quantify brain structure, three-dimensional T1-weighted magnetic resonance imaging (MRI) scans were performed at baseline and again after 24 months in 39 HIV+ patients on ART and 30 HIV- controls. Longitudinal changes in brain volume were measured using tissue segmentation within regions of interest and deformation morphometry. Measured by tissue segmentation, HIV+ patients on ART had significantly (all P<.05) greater rates of white matter volume loss than HIV- control individuals. Compared with controls, the subgroup of HIV+ individuals on ART with viral suppression also had significantly greater rates of white matter volume loss. Deformation morphometry confirmed these results with more specific spatial l...
Background-Prolonged disruption of sleep in animal studies is associated with decreased neurogene... more Background-Prolonged disruption of sleep in animal studies is associated with decreased neurogenesis in the dentate gyrus. Our objective was to determine if insomnia severity in a sample of PTSD and controls was associated with decreased volume in the CA3/dentate hippocampal subfield.
Context-Most neuroimaging studies of posttraumatic stress disorder (PTSD) have focused on potenti... more Context-Most neuroimaging studies of posttraumatic stress disorder (PTSD) have focused on potential abnormalities in the whole hippocampus, but the subfields of this structure, which have distinctive histological characteristics and specialized functions, have not been investigated. Studies of individual subfields may clarify the role of the hippocampus in PTSD.
microinfarcts showed a trend (p¼0.09) of greater rates of whole brain atrophy as compared to cont... more microinfarcts showed a trend (p¼0.09) of greater rates of whole brain atrophy as compared to controls. Total fractional WMH (p¼0.18) and rates of ventricular volume increase (p¼0.27) were not significantly greater in these patients. Conclusions: These results show that the presence and number of large cortical and subcortical infarctions on MRI are associated with presence of microinfarcts at autopsy. This data suggests that similar vascular disease mechanisms are responsible for the cortical and subcortical infarctions identified on antemortem MRI and microinfarcts identified at autopsy.
The objectives of this study were to (1) compare atrophy rates associated with normal aging and A... more The objectives of this study were to (1) compare atrophy rates associated with normal aging and Alzheimer disease (AD) using the semi-automated Boundary Shift Integral (BSI) method and manual tracing of the entorhinal cortex (ERC) and hippocampus and (2) calculate power of BSI vs. ERC and hippocampal volume changes for clinical trials in AD. We quantified whole brain and ventricular BSI atrophy rates and ERC and hippocampal atrophy rates from longitudinal MRI data in 20 AD patients and 22 age-matched healthy controls. All methods revealed significant brain atrophy in controls and AD patients. AD patients had approximately 2.5 times greater whole brain BSI atrophy rates and more than 5 times greater ERC and hippocampal atrophy rates than controls. ERC and hippocampal atrophy rates were higher in both groups than whole brain BSI atrophy rates, but lower than ventricular BSI atrophy rates. Effect size and power calculations suggest that ERC and hippocampal measurements may be more sens...
PURPOSE The diagnosis of Alzheimer’s disease currently requires neuropsychological assessment and... more PURPOSE The diagnosis of Alzheimer’s disease currently requires neuropsychological assessment and radiologic exclusion of structural abnormalities. There is increasing interest to identify individuals at risk for developing Alzheimer’s disease before irreversible neurodegeneration has occurred. Recent literature has suggested that temporal and parietal lobe volumes, particularly the hippocampus, are useful in discriminating those with Alzheimer’s disease from normal controls. The aim of this study is to determine whether automated volumetry of the temporal and parietal lobes from a baseline MRI predict those at risk for future memory decline among a multicenter cohort of elderly normals. METHOD AND MATERIALS The 191 participants (mean age = 76 +/- 5 years) were recruited through the Alzheimer’s Disease Neuroimaging Initiative (ADNI) as elderly controls and underwent a standardized baseline 1.5 T MRI scan, as well as neuropsychological assessment at baseline and after 2 years. No sig...
Alcohol-dependent individuals (ALC) have smaller hippocampi and poorer neurocognition than health... more Alcohol-dependent individuals (ALC) have smaller hippocampi and poorer neurocognition than healthy controls. Results from studies on the association between alcohol consumption and hippocampal volume have been mixed, suggesting that comorbid or premorbid factors (i.e., those present prior to the initiation of alcohol dependence) determine hippocampal volume in ALC.
This study was conducted to determine the relationship of frontal lobe cortical thickness and bas... more This study was conducted to determine the relationship of frontal lobe cortical thickness and basal ganglia volumes to measures of cognition in adults with sickle cell anemia (SCA). Participants included 120 adults with SCA with no history of neurologic dysfunction and 33 healthy controls (HCs). Participants were enrolled at 12 medical center sites, and raters were blinded to diagnostic group. We hypothesized that individuals with SCA would exhibit reductions in frontal lobe cortex thickness and reduced basal ganglia and thalamus volumes compared with HCs and that these structural brain abnormalities would be associated with measures of cognitive functioning (Wechsler Adult Intelligence Scale, 3rd edition). After adjusting for age, sex, education level, and intracranial volume, participants with SCA exhibited thinner frontal lobe cortex (t = -2.99, p = 0.003) and reduced basal ganglia and thalamus volumes compared with HCs (t = -3.95, p < 0.001). Reduced volume of the basal gangl...
The objectives of this study were to (1) compare atrophy rates associated with normal aging and A... more The objectives of this study were to (1) compare atrophy rates associated with normal aging and Alzheimer disease (AD) using the semi-automated Boundary Shift Integral (BSI) method and manual tracing of the entorhinal cortex (ERC) and hippocampus and (2) calculate power of BSI vs. ERC and hippocampal volume changes for clinical trials in AD. We quantified whole brain and ventricular BSI atrophy rates and ERC and hippocampal atrophy rates from longitudinal MRI data in 20 AD patients and 22 age-matched healthy controls. All methods revealed significant brain atrophy in controls and AD patients. AD patients had approximately 2.5 times greater whole brain BSI atrophy rates and more than 5 times greater ERC and hippocampal atrophy rates than controls. ERC and hippocampal atrophy rates were higher in both groups than whole brain BSI atrophy rates, but lower than ventricular BSI atrophy rates. Effect size and power calculations suggest that ERC and hippocampal measurements may be more sens...
T1 image,allowing assessment of volume, mean diffusivity (MD) and fractional anisotropy (FA) in t... more T1 image,allowing assessment of volume, mean diffusivity (MD) and fractional anisotropy (FA) in these regions. Longitudinal DT images were coregistered using tensor-based registration to examine FA, MD, axial and radial diffusivity (AD and RD) in the cingulum and fornix (ICBM-DTI-81 atlas). Whole brain and ventricular volumes were segmented using semi-automated techniques and atrophy/expansion rates calculated using the boundary shift integral. Linear regression, adjusting for age and gender, was used to assess differences in the imaging measures and their mean rates of change between MC and non-carrier groups. Results: The cohort comprised 12 mutation-negative participants and 17 MCs, six of whom reported symptoms at follow-up. MCs were on average 6.7 years younger than their parental age at symptom onset. MCs had smaller thalamic volumes bilaterally at baseline and follow-up, but there was little evidence for a difference in the rate of change over this interval. There was weak evidence for higher FA in bilateral thalamus and decreased AD in right cingulum at baseline and follow-up and lower right thalamic MD at baseline in MCs. When examined separately, MCs who became symptomatic had higher thalamic FA at follow-up than MCs who remained asymptomatic but both MC groups had smaller thalamic volumes than non-carriers. No significant group differences were evident for other imaging measures. Conclusions: Lower thalamic volumes and altered diffusivity were evident in FAD MCs compared to non-carriers at a stage when whole brain volumes and atrophy rates were similar. Thalamic FA in particular merits further investigation as a marker of early disease progression in larger FAD cohorts.
The goal of this study was to identify factors contributing to hippocampal atrophy rate (HAR) in ... more The goal of this study was to identify factors contributing to hippocampal atrophy rate (HAR) in clinically normal older adults (NC) and participants with mild cognitive impairment (MCI). Longitudinal HAR was measured on T1-weighted magnetic resonance imaging, and the contribution of age, gender, apolipoprotein E (ApoE) ε4 status, intracranial volume, white matter lesions, and β-amyloid (Aβ) levels to HAR was determined using linear regression. Age-related effects of HAR were compared in Aβ positive (Aβ+) and Aβ negative (Aβ-) participants. Age and Aβ levels had independent effects on HAR in NC, whereas gender, ApoE ε4 status, and Aβ levels were associated with HAR in MCI. In multivariable models, Aβ levels were associated with HAR in NC; ApoE ε4 and Aβ levels were associated with HAR in MCI. In MCI, age was a stronger predictor of HAR in Aβ- versus Aβ+ participants. HAR was higher in Aβ+ participants, but most of the HAR was because of factors other than Aβ status. Age-related effe...
The goal of this study was to assess the relationship between Ab deposition and white matter path... more The goal of this study was to assess the relationship between Ab deposition and white matter pathology (i.e., white matter hyperintensities, WMH) on microstructural integrity of the white matter. Fifty-seven participants (mean age: 7867 years) from an ongoing multi-site research program who spanned the spectrum of normal to mild cognitive impairment (Clinical dementia rating 0-0.5) and low to high risk factors for arteriosclerosis and WMH pathology (defined as WMH volume .0.5% total intracranial volume) were assessed with positron emission tomography (PET) with Pittsburg compound B (PiB) and magnetic resonance and diffusion tensor imaging (DTI). Multivariate analysis of covariance were used to investigate the relationship between Ab deposition and WMH pathology on fractional anisotropy (FA) from 9 tracts of interest (i.e., corona radiata, internal capsule, cingulum, parahippocampal white matter, corpus callosum, superior longitudinal, superior and inferior front-occipital fasciculi, and fornix). WMH pathology was associated with reduced FA in projection (i.e., internal capsule and corona radiate) and association (i.e., superior longitudinal, superior and inferior fronto-occipital fasciculi) fiber tracts. Ab deposition (i.e., PiB positivity) was associated with reduced FA in the fornix and splenium of the corpus callosum. There were interactions between PiB and WMH pathology in the internal capsule and parahippocampal white matter, where Ab deposition reduced FA more among subjects with WMH pathology than those without. However, accounting for apoE e4 genotype rendered these interactions insignificant. Although this finding suggests that apoE4 may increase amyloid deposition, both in the parenchyma (resulting in PiB positivity) and in blood vessels (resulting in amyloid angiopathy and WMH pathology), and that these two factors together may be associated with compromised white matter microstructural integrity in multiple brain regions, additional studies with a longitudinal design will be necessary to resolve this issue.
Our MR/MRS imaging studies of HIV, alcohol, ALS, dementia, and aging require experienced anatomis... more Our MR/MRS imaging studies of HIV, alcohol, ALS, dementia, and aging require experienced anatomists to delineate subcortical structures and lobar boundaries by hand. This requires rigorous training to ensure good intra-and inter-rater reliability, and an enormous investment of time. We are interested in developing an automated method for Identifying the boundaries of subcortical strnctnres and lobes. In brief, our approach is to identify the stmctnres of interest on a template or atlas brain, warp the template brain to a new subject's brain (i.e.. target brain) using the gray scale images, then to apply the resultant warp to the strncture identified on the template brain. This abstract describes our initial efforts at implementing and evaluating this approach.
The goal was to elucidate the time course of regional brain atrophy rates relative to age in cogn... more The goal was to elucidate the time course of regional brain atrophy rates relative to age in cognitively normal (CN) aging, mild cognitively impairment (MCI) and Alzheimer's disease (AD), without a-priori models for atrophy progression. Regional brain volumes from 147 CN subjects, 164 stable MCI, 93 MCI-to-AD converters and 111 AD patients, between 51 to 91 years old and who had repeated 1.5T magnetic resonance imaging (MRI) scans over 30 months, were analyzed. Relations between regional brain volume change and age were determined using generalized additive models, an established non-parametric concept for approximating nonlinear relations. Brain atrophy rates varied nonlinearly with age, predominantly in regions of the temporal lobe. Moreover, the atrophy rates of some regions leveled off with increasing age in control and stable MCI subjects whereas those rates progressed further in MCI-to-AD converters and AD patients. The approach has potential uses for early detection of AD and differentiation between stable and progressing MCI.
A previous study (1) suggested that individuals with Gulf War Illness (GWI) had reduced quantitie... more A previous study (1) suggested that individuals with Gulf War Illness (GWI) had reduced quantities of the neuronal marker N-acetyl aspartate (NAA) in the basal ganglia and pons. This study aimed to determine whether NAA is reduced in these regions and to investigate correlations with other possible causes of GWI, such as psychological response to stress in a large cohort of Gulf war veterans. Individuals underwent tests to determine their physical and psychological health and to identify veterans with (n=81) and without (n=97) GWI. When concentrations of NAA and ratios of NAA to creatine-and choline-containing metabolites were measured in the basal ganglia and pons, no significant differences were found between veterans with or without GWI, suggesting that GWI is not associated with reduced NAA in these regions. Veterans with GWI had significantly higher rates of Post Traumatic Stress Disorder (PTSD), supporting the idea that GWI symptoms are stress-related.
Context-Sickle cell anemia (SCA) is a chronic illness causing progressive deterioration in qualit... more Context-Sickle cell anemia (SCA) is a chronic illness causing progressive deterioration in quality of life. Brain dysfunction may be the most important and least studied problem affecting individuals with this disease.
Treatment with antiretroviral therapy (ART) has greatly reduced the incidence of dementia. The go... more Treatment with antiretroviral therapy (ART) has greatly reduced the incidence of dementia. The goal of this longitudinal study was to determine if there are ongoing macrostructural brain changes in human immunodeficiency virus-positive (HIV + ) individuals treated with ART. To quantify brain structure, three-dimensional T1-weighted magnetic resonance imaging (MRI) scans were performed at baseline and again after 24 months in 39 HIV+ patients on ART and 30 HIV- controls. Longitudinal changes in brain volume were measured using tissue segmentation within regions of interest and deformation morphometry. Measured by tissue segmentation, HIV+ patients on ART had significantly (all P<.05) greater rates of white matter volume loss than HIV- control individuals. Compared with controls, the subgroup of HIV+ individuals on ART with viral suppression also had significantly greater rates of white matter volume loss. Deformation morphometry confirmed these results with more specific spatial l...
Background-Prolonged disruption of sleep in animal studies is associated with decreased neurogene... more Background-Prolonged disruption of sleep in animal studies is associated with decreased neurogenesis in the dentate gyrus. Our objective was to determine if insomnia severity in a sample of PTSD and controls was associated with decreased volume in the CA3/dentate hippocampal subfield.
Context-Most neuroimaging studies of posttraumatic stress disorder (PTSD) have focused on potenti... more Context-Most neuroimaging studies of posttraumatic stress disorder (PTSD) have focused on potential abnormalities in the whole hippocampus, but the subfields of this structure, which have distinctive histological characteristics and specialized functions, have not been investigated. Studies of individual subfields may clarify the role of the hippocampus in PTSD.
microinfarcts showed a trend (p¼0.09) of greater rates of whole brain atrophy as compared to cont... more microinfarcts showed a trend (p¼0.09) of greater rates of whole brain atrophy as compared to controls. Total fractional WMH (p¼0.18) and rates of ventricular volume increase (p¼0.27) were not significantly greater in these patients. Conclusions: These results show that the presence and number of large cortical and subcortical infarctions on MRI are associated with presence of microinfarcts at autopsy. This data suggests that similar vascular disease mechanisms are responsible for the cortical and subcortical infarctions identified on antemortem MRI and microinfarcts identified at autopsy.
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