The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
Edythe D. London - One of the best experts on this subject based on the ideXlab platform.
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Cigarette smoking and white matter microstructure
Psychopharmacology, 2012Co-Authors: Matthew Hudkins, George Bartzokis, Joseph O’neill, Marc C. Tobias, Edythe D. LondonAbstract:Rationale Diffusion tensor imaging has been used before in testing associations between cigarette smoking and white matter integrity, with inconsistent results. Published reports indicate higher fractional anisotropy (FA, a measure of linear water diffusion) in some brain regions and lower FA in others in adult smokers compared to nonsmokers. Adolescent smokers exhibited elevated FA at several brain regions and a positive correlation of FA in the Genu Corpus Callosum with exposure to smoking (pack-years). Objective To help resolve prior discrepancies, we studied adults, sampling multiple brain regions, and testing for relationships to clinical features of nicotine dependence and exposure to smoking. Methods Brain MRI scans (1.5 T) were acquired, and FA and apparent diffusion coefficient (ADC, a measure of random diffusion) were assayed in Corpus Callosum and prefrontal white matter, corona radiata, internal capsule, cingulum bundle, and hippocampal perforant fibers in 18 smokers (33.7 ± 7.9 years of age) and 18 age- and gender-matched nonsmokers. Results ADC showed no group difference, but smokers had higher (4.3–21.1%) FA than nonsmokers. The differences were significant in right prefrontal white matter, cingulum, and Genu Corpus Callosum. FA in several regions was negatively correlated with nicotine dependence or cigarettes/day. Conclusions Combined with earlier findings, these results suggest a model of changing trajectories whereby FA is higher with tobacco exposure during adolescence and declines with continued smoking in adulthood. This notion is supported by the observation that, at multiple sampling sites, participants who had started smoking earlier in life had higher FA than those who had started later.
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Cigarette smoking and white matter microstructure.
Psychopharmacology, 2012Co-Authors: Matthew Hudkins, Joseph O'neill, Marc Tobias, George Bartzokis, Edythe D. LondonAbstract:Rationale Diffusion tensor imaging has been used before in testing associations between cigarette smoking and white matter integrity, with inconsistent results. Published reports indicate higher fractional anisotropy (FA, a measure of linear water diffusion) in some brain regions and lower FA in others in adult smokers compared to nonsmokers. Adolescent smokers exhibited elevated FA at several brain regions and a positive correlation of FA in the Genu Corpus Callosum with exposure to smoking (pack-years).
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White-matter abnormalities in brain during early abstinence from methamphetamine abuse
Psychopharmacology, 2010Co-Authors: Marc C. Tobias, Matthew Hudkins, George Bartzokis, Joseph O’neill, Andrew C. Dean, Edythe D. LondonAbstract:Background Previous studies revealed microstructural abnormalities in prefrontal white matter and Corpus Callosum of long-term abstinent chronic methamphetamine abusers. In view of the importance of the early abstinence period in treatment retention, we compared 23 methamphetamine-dependent subjects abstinent from methamphetamine for 7–13 days with 18 healthy comparison subjects. As certain metabolic changes in the brain first manifest after early abstinence from methamphetamine, it is also possible that microstructural white-matter abnormalities are not yet present during early abstinence. Methods Using diffusion tensor imaging at 1.5 T, fractional anisotropy (FA) was measured in prefrontal white matter at four inferior–superior levels parallel to the anterior commissure–posterior commissure (AC–PC) plane. We also sampled FA in the Corpus Callosum at the midline and at eight bilateral, fiber-tract sites in other regions implicated in effects of methamphetamine. Results The methamphetamine group exhibited lower FA in right prefrontal white matter above the AC–PC plane (11.9% lower; p = 0.007), in midline Genu Corpus Callosum (3.9%; p = 0.019), in left and right midcaudal superior corona radiata (11.0% in both hemispheres, p ’s = 0.020 and 0.016, respectively), and in right perforant fibers (7.3%; p = 0.025). FA in left midcaudal superior corona radiata was correlated with depressive and generalized psychiatric symptoms within the methamphetamine group. Conclusions The findings support the idea that methamphetamine abuse produces microstructural abnormalities in white matter underlying and interconnecting prefrontal cortices and hippocampal formation. These effects are already present during the first weeks of abstinence from methamphetamine and are linked to psychiatric symptoms assessed during this period.
Fabiano G. Nery - One of the best experts on this subject based on the ideXlab platform.
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anterior Genu Corpus Callosum and impulsivity in suicidal patients with bipolar disorder
Neuroscience Letters, 2010Co-Authors: Koji Matsuo, Niels Nielsen, Mark Nicoletti, John P. Hatch, Yoshifumi Watanabe, Fabiano G. Nery, Serap E Monkul, Giovana ZuntasoaresAbstract:Suicidality is a life-threatening symptom in patients with bipolar disorder (BD). Impulsivity and mood instability are associated with suicidality in mood disorders. Evidence suggests that gray and white matter abnormalities are linked with impulsivity in mood disorders, but little is known about the association between Corpus Callosum (CC) and impulsivity in BD. We examined the relationship between CC areas, impulsivity and suicidality in BD patients. We studied 10 female BD patients with a history of suicide attempt (mean+/-SD age 36.2+/-10.1 years), 10 female BD patients without suicide attempt history (44.2+/-12.5 years) and 27 female healthy subjects (36.9+/-13.8 years). Impulsivity was evaluated by the Barratt Impulsivity Scale (BIS). We traced MR images to measure the areas of the CC Genu, anterior body, posterior body, isthmus and splenium. The Genu was divided into anterior, middle and posterior regions. The suicidal and non-suicidal BD patients had significantly higher BIS total, attention and non-planning scores than the healthy subjects (ps<0.01), and the suicidal BD patients had significantly higher BIS motor scores than the non-suicidal BD and healthy subjects (ps<0.01). There were no significant differences among the three groups on any regional CC areas, although the suicidal BD patients had the smallest areas. The suicidal BD patients showed a significant inverse correlation between anterior Genu area and the BIS total (r=-0.75, p=0.04), motor (r=-0.79, p=0.02) and non-planning scores (r=-0.79, p=0.02). These correlations were not found in the non-suicidal BD patients or healthy subjects. The results suggest that the anterior medial frontal region may be involved in the pathophysiology of impulsive and suicidal behaviors in BD.
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Anterior Genu Corpus Callosum and impulsivity in suicidal patients with bipolar disorder
Neuroscience letters, 2009Co-Authors: Koji Matsuo, Niels Nielsen, Mark Nicoletti, John P. Hatch, E. Serap Monkul, Yoshifumi Watanabe, Giovana Zunta-soares, Fabiano G. Nery, Jair C. SoaresAbstract:Suicidality is a life-threatening symptom in patients with bipolar disorder (BD). Impulsivity and mood instability are associated with suicidality in mood disorders. Evidence suggests that gray and white matter abnormalities are linked with impulsivity in mood disorders, but little is known about the association between Corpus Callosum (CC) and impulsivity in BD. We examined the relationship between CC areas, impulsivity and suicidality in BD patients. We studied 10 female BD patients with a history of suicide attempt (mean+/-SD age 36.2+/-10.1 years), 10 female BD patients without suicide attempt history (44.2+/-12.5 years) and 27 female healthy subjects (36.9+/-13.8 years). Impulsivity was evaluated by the Barratt Impulsivity Scale (BIS). We traced MR images to measure the areas of the CC Genu, anterior body, posterior body, isthmus and splenium. The Genu was divided into anterior, middle and posterior regions. The suicidal and non-suicidal BD patients had significantly higher BIS total, attention and non-planning scores than the healthy subjects (ps
Matthew Hudkins - One of the best experts on this subject based on the ideXlab platform.
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Cigarette smoking and white matter microstructure
Psychopharmacology, 2012Co-Authors: Matthew Hudkins, George Bartzokis, Joseph O’neill, Marc C. Tobias, Edythe D. LondonAbstract:Rationale Diffusion tensor imaging has been used before in testing associations between cigarette smoking and white matter integrity, with inconsistent results. Published reports indicate higher fractional anisotropy (FA, a measure of linear water diffusion) in some brain regions and lower FA in others in adult smokers compared to nonsmokers. Adolescent smokers exhibited elevated FA at several brain regions and a positive correlation of FA in the Genu Corpus Callosum with exposure to smoking (pack-years). Objective To help resolve prior discrepancies, we studied adults, sampling multiple brain regions, and testing for relationships to clinical features of nicotine dependence and exposure to smoking. Methods Brain MRI scans (1.5 T) were acquired, and FA and apparent diffusion coefficient (ADC, a measure of random diffusion) were assayed in Corpus Callosum and prefrontal white matter, corona radiata, internal capsule, cingulum bundle, and hippocampal perforant fibers in 18 smokers (33.7 ± 7.9 years of age) and 18 age- and gender-matched nonsmokers. Results ADC showed no group difference, but smokers had higher (4.3–21.1%) FA than nonsmokers. The differences were significant in right prefrontal white matter, cingulum, and Genu Corpus Callosum. FA in several regions was negatively correlated with nicotine dependence or cigarettes/day. Conclusions Combined with earlier findings, these results suggest a model of changing trajectories whereby FA is higher with tobacco exposure during adolescence and declines with continued smoking in adulthood. This notion is supported by the observation that, at multiple sampling sites, participants who had started smoking earlier in life had higher FA than those who had started later.
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Cigarette smoking and white matter microstructure.
Psychopharmacology, 2012Co-Authors: Matthew Hudkins, Joseph O'neill, Marc Tobias, George Bartzokis, Edythe D. LondonAbstract:Rationale Diffusion tensor imaging has been used before in testing associations between cigarette smoking and white matter integrity, with inconsistent results. Published reports indicate higher fractional anisotropy (FA, a measure of linear water diffusion) in some brain regions and lower FA in others in adult smokers compared to nonsmokers. Adolescent smokers exhibited elevated FA at several brain regions and a positive correlation of FA in the Genu Corpus Callosum with exposure to smoking (pack-years).
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White-matter abnormalities in brain during early abstinence from methamphetamine abuse
Psychopharmacology, 2010Co-Authors: Marc C. Tobias, Matthew Hudkins, George Bartzokis, Joseph O’neill, Andrew C. Dean, Edythe D. LondonAbstract:Background Previous studies revealed microstructural abnormalities in prefrontal white matter and Corpus Callosum of long-term abstinent chronic methamphetamine abusers. In view of the importance of the early abstinence period in treatment retention, we compared 23 methamphetamine-dependent subjects abstinent from methamphetamine for 7–13 days with 18 healthy comparison subjects. As certain metabolic changes in the brain first manifest after early abstinence from methamphetamine, it is also possible that microstructural white-matter abnormalities are not yet present during early abstinence. Methods Using diffusion tensor imaging at 1.5 T, fractional anisotropy (FA) was measured in prefrontal white matter at four inferior–superior levels parallel to the anterior commissure–posterior commissure (AC–PC) plane. We also sampled FA in the Corpus Callosum at the midline and at eight bilateral, fiber-tract sites in other regions implicated in effects of methamphetamine. Results The methamphetamine group exhibited lower FA in right prefrontal white matter above the AC–PC plane (11.9% lower; p = 0.007), in midline Genu Corpus Callosum (3.9%; p = 0.019), in left and right midcaudal superior corona radiata (11.0% in both hemispheres, p ’s = 0.020 and 0.016, respectively), and in right perforant fibers (7.3%; p = 0.025). FA in left midcaudal superior corona radiata was correlated with depressive and generalized psychiatric symptoms within the methamphetamine group. Conclusions The findings support the idea that methamphetamine abuse produces microstructural abnormalities in white matter underlying and interconnecting prefrontal cortices and hippocampal formation. These effects are already present during the first weeks of abstinence from methamphetamine and are linked to psychiatric symptoms assessed during this period.
George Bartzokis - One of the best experts on this subject based on the ideXlab platform.
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Cigarette smoking and white matter microstructure
Psychopharmacology, 2012Co-Authors: Matthew Hudkins, George Bartzokis, Joseph O’neill, Marc C. Tobias, Edythe D. LondonAbstract:Rationale Diffusion tensor imaging has been used before in testing associations between cigarette smoking and white matter integrity, with inconsistent results. Published reports indicate higher fractional anisotropy (FA, a measure of linear water diffusion) in some brain regions and lower FA in others in adult smokers compared to nonsmokers. Adolescent smokers exhibited elevated FA at several brain regions and a positive correlation of FA in the Genu Corpus Callosum with exposure to smoking (pack-years). Objective To help resolve prior discrepancies, we studied adults, sampling multiple brain regions, and testing for relationships to clinical features of nicotine dependence and exposure to smoking. Methods Brain MRI scans (1.5 T) were acquired, and FA and apparent diffusion coefficient (ADC, a measure of random diffusion) were assayed in Corpus Callosum and prefrontal white matter, corona radiata, internal capsule, cingulum bundle, and hippocampal perforant fibers in 18 smokers (33.7 ± 7.9 years of age) and 18 age- and gender-matched nonsmokers. Results ADC showed no group difference, but smokers had higher (4.3–21.1%) FA than nonsmokers. The differences were significant in right prefrontal white matter, cingulum, and Genu Corpus Callosum. FA in several regions was negatively correlated with nicotine dependence or cigarettes/day. Conclusions Combined with earlier findings, these results suggest a model of changing trajectories whereby FA is higher with tobacco exposure during adolescence and declines with continued smoking in adulthood. This notion is supported by the observation that, at multiple sampling sites, participants who had started smoking earlier in life had higher FA than those who had started later.
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Cigarette smoking and white matter microstructure.
Psychopharmacology, 2012Co-Authors: Matthew Hudkins, Joseph O'neill, Marc Tobias, George Bartzokis, Edythe D. LondonAbstract:Rationale Diffusion tensor imaging has been used before in testing associations between cigarette smoking and white matter integrity, with inconsistent results. Published reports indicate higher fractional anisotropy (FA, a measure of linear water diffusion) in some brain regions and lower FA in others in adult smokers compared to nonsmokers. Adolescent smokers exhibited elevated FA at several brain regions and a positive correlation of FA in the Genu Corpus Callosum with exposure to smoking (pack-years).
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White-matter abnormalities in brain during early abstinence from methamphetamine abuse
Psychopharmacology, 2010Co-Authors: Marc C. Tobias, Matthew Hudkins, George Bartzokis, Joseph O’neill, Andrew C. Dean, Edythe D. LondonAbstract:Background Previous studies revealed microstructural abnormalities in prefrontal white matter and Corpus Callosum of long-term abstinent chronic methamphetamine abusers. In view of the importance of the early abstinence period in treatment retention, we compared 23 methamphetamine-dependent subjects abstinent from methamphetamine for 7–13 days with 18 healthy comparison subjects. As certain metabolic changes in the brain first manifest after early abstinence from methamphetamine, it is also possible that microstructural white-matter abnormalities are not yet present during early abstinence. Methods Using diffusion tensor imaging at 1.5 T, fractional anisotropy (FA) was measured in prefrontal white matter at four inferior–superior levels parallel to the anterior commissure–posterior commissure (AC–PC) plane. We also sampled FA in the Corpus Callosum at the midline and at eight bilateral, fiber-tract sites in other regions implicated in effects of methamphetamine. Results The methamphetamine group exhibited lower FA in right prefrontal white matter above the AC–PC plane (11.9% lower; p = 0.007), in midline Genu Corpus Callosum (3.9%; p = 0.019), in left and right midcaudal superior corona radiata (11.0% in both hemispheres, p ’s = 0.020 and 0.016, respectively), and in right perforant fibers (7.3%; p = 0.025). FA in left midcaudal superior corona radiata was correlated with depressive and generalized psychiatric symptoms within the methamphetamine group. Conclusions The findings support the idea that methamphetamine abuse produces microstructural abnormalities in white matter underlying and interconnecting prefrontal cortices and hippocampal formation. These effects are already present during the first weeks of abstinence from methamphetamine and are linked to psychiatric symptoms assessed during this period.
Marc C. Tobias - One of the best experts on this subject based on the ideXlab platform.
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Cigarette smoking and white matter microstructure
Psychopharmacology, 2012Co-Authors: Matthew Hudkins, George Bartzokis, Joseph O’neill, Marc C. Tobias, Edythe D. LondonAbstract:Rationale Diffusion tensor imaging has been used before in testing associations between cigarette smoking and white matter integrity, with inconsistent results. Published reports indicate higher fractional anisotropy (FA, a measure of linear water diffusion) in some brain regions and lower FA in others in adult smokers compared to nonsmokers. Adolescent smokers exhibited elevated FA at several brain regions and a positive correlation of FA in the Genu Corpus Callosum with exposure to smoking (pack-years). Objective To help resolve prior discrepancies, we studied adults, sampling multiple brain regions, and testing for relationships to clinical features of nicotine dependence and exposure to smoking. Methods Brain MRI scans (1.5 T) were acquired, and FA and apparent diffusion coefficient (ADC, a measure of random diffusion) were assayed in Corpus Callosum and prefrontal white matter, corona radiata, internal capsule, cingulum bundle, and hippocampal perforant fibers in 18 smokers (33.7 ± 7.9 years of age) and 18 age- and gender-matched nonsmokers. Results ADC showed no group difference, but smokers had higher (4.3–21.1%) FA than nonsmokers. The differences were significant in right prefrontal white matter, cingulum, and Genu Corpus Callosum. FA in several regions was negatively correlated with nicotine dependence or cigarettes/day. Conclusions Combined with earlier findings, these results suggest a model of changing trajectories whereby FA is higher with tobacco exposure during adolescence and declines with continued smoking in adulthood. This notion is supported by the observation that, at multiple sampling sites, participants who had started smoking earlier in life had higher FA than those who had started later.
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White-matter abnormalities in brain during early abstinence from methamphetamine abuse
Psychopharmacology, 2010Co-Authors: Marc C. Tobias, Matthew Hudkins, George Bartzokis, Joseph O’neill, Andrew C. Dean, Edythe D. LondonAbstract:Background Previous studies revealed microstructural abnormalities in prefrontal white matter and Corpus Callosum of long-term abstinent chronic methamphetamine abusers. In view of the importance of the early abstinence period in treatment retention, we compared 23 methamphetamine-dependent subjects abstinent from methamphetamine for 7–13 days with 18 healthy comparison subjects. As certain metabolic changes in the brain first manifest after early abstinence from methamphetamine, it is also possible that microstructural white-matter abnormalities are not yet present during early abstinence. Methods Using diffusion tensor imaging at 1.5 T, fractional anisotropy (FA) was measured in prefrontal white matter at four inferior–superior levels parallel to the anterior commissure–posterior commissure (AC–PC) plane. We also sampled FA in the Corpus Callosum at the midline and at eight bilateral, fiber-tract sites in other regions implicated in effects of methamphetamine. Results The methamphetamine group exhibited lower FA in right prefrontal white matter above the AC–PC plane (11.9% lower; p = 0.007), in midline Genu Corpus Callosum (3.9%; p = 0.019), in left and right midcaudal superior corona radiata (11.0% in both hemispheres, p ’s = 0.020 and 0.016, respectively), and in right perforant fibers (7.3%; p = 0.025). FA in left midcaudal superior corona radiata was correlated with depressive and generalized psychiatric symptoms within the methamphetamine group. Conclusions The findings support the idea that methamphetamine abuse produces microstructural abnormalities in white matter underlying and interconnecting prefrontal cortices and hippocampal formation. These effects are already present during the first weeks of abstinence from methamphetamine and are linked to psychiatric symptoms assessed during this period.