Prior research has suggested an association between exposure to infectious disease and neurocogni... more Prior research has suggested an association between exposure to infectious disease and neurocognitive function in humans. While most of these studies have explored individual viral, bacterial, and even parasitic sources of infection, few have considered the potential neurocognitive burden associated with multiple infections. In this study, we utilized publically available data from a large dataset produced by the Centers for Disease Control and Prevention that included measures of neurocognitive function, sociodemographic variables, and serum antibody data for several infectious diseases. Specifically, immunoglobulin G antibodies for toxocariasis, toxoplasmosis, hepatitis A, hepatitis B, and hepatitis C, cytomegalovirus, and herpes 1 and 2 were available in 5662 subjects. We calculated an overall index of infectious-disease burden to determine if an aggregate measure of exposure to infectious disease would be associated with neurocognitive function in adults aged 20–59 years. The index predicted processing speed and learning and memory but not reaction time after controlling for age, sex, race-ethnicity, immigration status, education, and the poverty-to-income ratio. Interactions between the infectious-disease index and some sociodemographic variables were also associated with neurocognitive function. In summary, an index aggregating exposure to several infectious diseases was associated with neurocognitive function in young-to middle-aged adults.
Background: Helicobacter pylori (H. pylori) infection is associated with cogni-tive deficits in h... more Background: Helicobacter pylori (H. pylori) infection is associated with cogni-tive deficits in humans, an association potentially mediated or moderated by folate concentration or inflammation.
Materials and Methods: We used the National Health and Nutrition Examination Survey (NHANES) datasets to examine whether folate concentration or inflammation mediates or moderates the relationship between H. pylori and cognitive function. Models were performed using linear, Poisson, and zero-inflated Poisson regression, and we performed separate analyses for groups aged 20–59 and 60–90 years with sample sizes ranging from 700 to 1700.
Results: We did not find evidence of mediation in either age group. In the 20-to 59-year group, interactions between H. pylori and ferritin (p values ranging from .004 to .039) were associated with worse processing speed, better working memory, and worse reaction time. Interactions between H. pylori and fibrinogen (p values ranging from .023 to .045), C-reactive protein (CRP) (p = .023), and the inflammatory index (p = .045) were associated with worse processing speed. In 60-to 90-year-olds, H. pylori interacted with ferritin and the inflammatory index to predict fewer mathematical errors (p values of .036 and .023). Interactions with folate (p values of .016 and .006) and C-reactive protein (p values ranging from <.001 to .048) were inconsistent in directionality.
Conclusions: In this dataset, representative of the US population, inflammation and folate concentrations moderated but did not mediate the association between H. pylori seropositivity and cognition.
To determine the magnitude and time course of changes in the volume of brain and intracranial cer... more To determine the magnitude and time course of changes in the volume of brain and intracranial cerebrospinal fluid (CSF) spaces in patients who have sustained traumatic brain injury and to assess the relationship between these findings and long-term cognitive traumatic outcome. Axial intermediate and T2-weighted MR images of 123 patients with traumatic brain injury were quantified using a multispectral segmentation algorithm. Measurements were corrected for differences in age, sex, and head size using a previously reported normative database. Brain morphology was compared across groups formed on the basis of chronicity of injury. Cognitive functioning and severity of injury were statistically correlated with brain measurements. Time-dependent expansion of CSF spaces and decreases in brain volume were observed. Increases in ventricular CSF volume, particularly in the temporal horns and third ventricle, preceded subsequent changes in total brain and subarachnoid CSF. High and moderate ...
To present a normative database of hippocampal and temporal horn volume and to clarify the relati... more To present a normative database of hippocampal and temporal horn volume and to clarify the relationship between these measures and cognitive outcome in patients with traumatic brain injury. Ninety-six healthy volunteers and 94 patients with traumatic brain injury were examined with coronal intermediate and T2-weighted MR imaging. Multispectral segmentation and volume analyses were performed. The volumetry of the hippocampus and temporal horn was characterized in the control subjects. Volumetric measures in a group of patients with traumatic brain injury who had received MR imaging 3 months or less after injury were compared with measurements in other patients in the chronic phase of recovery. The relationship between neuropsychological testing and volumetric measures was analyzed with particular emphasis on the correlation between cognitive outcome and hippocampal and temporal horn volumes. No significant age group differences were found in the normative group from age 16 to 65. Lef...
PURPOSE: To present a normative volumetric database, spanning 5 decades of life, of cerebro- spin... more PURPOSE: To present a normative volumetric database, spanning 5 decades of life, of cerebro- spinal fluid, subarachnoid cerebrospinal fluid, total brain volume, total ventricular volume (com- ponent ventricular volumes of lateral, temporal horn, and third and fourth ventricles) and estimates of white and gray matter, based on a multispectral segmentation of brain MR. This database is presented as a reference
Advances in neuroimaging have greatly improved our understanding of stroke not only in the acute,... more Advances in neuroimaging have greatly improved our understanding of stroke not only in the acute, but also in the subacute and chronic stages of recovery. More recently developed magnetic resonance techniques such as diffusion and perfusion weighted imaging, as well as more traditional magnetic resonance and computed tomography studies allow clinicians to more accurately diagnosis stroke subtypes, optimize treatment, and predict prognosis. Although not widely utilized for clinical use, functional neuroimaging techniques have also been shown to be useful in terms of predicting prognosis and advancing our understanding of reorganization and recovery following stroke. Thus, neuroimaging in stroke may also be utilized to monitor response to both medical treatment as well as physical rehabilitation. The following is a review of current research relevant to the field of neuroimaging of stroke. We begin with a discussion of structural imaging techniques with the goal of familiarizing the r...
Latent infection from Toxoplasma gondii (T. gondii) is widespread worldwide and has been associat... more Latent infection from Toxoplasma gondii (T. gondii) is widespread worldwide and has been associated with cognitive deficits in some but not all animal models and in humans. We tested the hypothesis that latent toxoplasmosis is associated with decreased cognitive function in a large cross-sectional dataset, the National Health and Nutrition Examination Survey (NHANES). There were 4178 participants aged 20–59 years, of whom 19·1% had IgG antibodies against T. gondii. Two ordinary least squares (OLS) regression models adjusted for the NHANES complex sampling design and weighted to represent the US population were estimated for simple reaction time, processing speed and short-term memory or attention. The first model included only main effects of latent toxoplasmosis and demographic control variables, and the second added interaction terms between latent toxoplasmosis and the poverty-to-income ratio (PIR), educational attainment and raceethnicity. We also used multivariate models to assess all three cognitive outcomes in the same model. Although the models evaluating main effects only demonstrated no association between latent toxoplasmosis and the cognitive outcomes, significant interactions between latent toxoplasmosis and the PIR, between latent toxoplasmosis and educational attainment, and between latent toxoplasmosis and race-ethnicity indicated that latent toxoplasmosis may adversely affect cognitive function in certain groups.
Latent infection with the apicomplexan Toxoplasma gondii (Nicolle et Manceaux, 1908) has been ass... more Latent infection with the apicomplexan Toxoplasma gondii (Nicolle et Manceaux, 1908) has been associated with schizophrenia, bipolar disorder and self-harm behaviour. However, the potential relationship between T. gondii immunoglobulin G antibody (IgG) seropositivity and generalised-anxiety disorder (GAD) and panic disorder (PD) has not been investigated. The associations between serum reactivity to T. gondii and major depressive disorder (MDD), GAD and PD were evaluated in a total sample of 1 846 adult participants between the ages of 20 and 39 years from the United States Center for Disease Control’s National Health and Nutrition Examination Survey (NHANES). Approximately 16% of the overall sample was seropositive for T. gondii and 7% of the sample met criteria for MDD, 2% for GAD and 2% for PD. There were no significant associations between T. gondii IgG seroprevalence and MDD (OR = 0.484, 95% CI = 0.186–1.258), GAD (OR = 0.737, 95% CI = 0.218–2.490) or PD (OR = 0.683, 95% CI = 0.206–2.270) controlling for sex, ethnicity, poverty-to-income ratio and educational attainment. However, limited evidence suggested a possible association between absolute antibody titres for T. gondii and GAD and PD but not MDD. Toxoplasma gondii seroprevalence was not associated with MDD, GAD or PD within the context of the limitations of this study, although there may be an association of T. gondii serointensity with and GAD and PD, which requires further study.
A modification of the Fuld Object Memory Evaluation (FOME) was administered to 232 normally funct... more A modification of the Fuld Object Memory Evaluation (FOME) was administered to 232 normally functioning children in grades one through eight in a public school district in Phoenix, Arizona. The test was terminated once all 10 objects were successfully recalled by the child. Ceiling effects were observed as 226 out of 232 children (97.4%) recalled all 10 objects on or before the fourth trial. Ineffective reminders were rare. Ceiling effects were studied as a function of age and grade level. The information may be helpful when examining children with severe cognitive impairments or from different cultural backgrounds.
The purpose of this study was to assess the feasibility of utilizing low-current stimulation for ... more The purpose of this study was to assess the feasibility of utilizing low-current stimulation for F-wave generation, thereby avoiding the discomfort of repetitive supramaximal stimulation. We employed the same technique as is used for generating F waves in the conventional way, except for using a stimulating current that was just strong enough to evoke a motor response on the oscilloscope. This usually required a stimulus of about 10–15 mA at 0.2-ms duration. Both median nerves of 30 subjects were evaluated with this technique and with F waves generated by the conventional technique in the same subjects. Amplitudes were larger when using supramaximal current stimulation. However, there was no statistical difference between F-wave latencies, chronodispersion, and persistence (penetrance) elicited with maximal and low-current stimulation. This procedure should represent a significant improvement for patient comfort during electrodiagnostic procedures involving F-wave studies. Muscle Nerve 28: 82–86, 2003
Two studies were conducted to determine the frequency of processing speed difficulties relative t... more Two studies were conducted to determine the frequency of processing speed difficulties relative to estimates of other problem-solving abilities in children with and without traumatic brain injury (TBI). The two samples consisted of 213 normally functioning school-age children and 65 TBI children and 19 trauma controls. All children were administered the WISC-III/IV Vocabulary, Block Design, and Coding subtests. The frequency of children in each sample having a Coding subtest score of 3 or 4 scale points below the Vocabulary or Block Design score (whichever one was lower) was calculated. Using a 3-point scale difference, the presence of processing speed deficits relative to other cognitive abilities in the school sample was low (5.2%), and was equivalent to that demonstrated by trauma controls (5.3%). However, in the TBI sample, 18 out of 65 TBI patients (27.7%) showed this same pattern. Using a 4-point discrepancy scale, 3.3% of normal children and 16.9% of TBI children showed this pattern. The frequency of this pattern increased with severity of TBI, using two different but related classification systems. These preliminary findings require cross validation in a larger sample before definite conclusions can be reached.
... ERIN D. BIGLER, C. STERLING JOHNSON, CAROL ANDERSON, AND SHAWN D. GALE Department of Psycholo... more ... ERIN D. BIGLER, C. STERLING JOHNSON, CAROL ANDERSON, AND SHAWN D. GALE Department of Psychology, Brigham Young University, Provo ... of the MRI in the normal and medical control with autopsy reports (Ho, Roessmann, Straumfjord, &amp; Monroe, 1980; Dekaban &amp; ...
Primary intracerebral haemorrhage (ICH) is a common and devastating disorder that often results i... more Primary intracerebral haemorrhage (ICH) is a common and devastating disorder that often results in long-term disability. This review examines the literature on predictors of survival and long-term functional outcome after ICH. Medical literature review. Numerous clinical and radiologic variables have been shown to be associated with survival and functional recovery following ICH. These include patient age and gender, lesion size and location, initial level of consciousness, presence of intraventricular haemorrhage, hydrocephalus, and mass effect. Studies have employed a variety of outcome measures including survival and functional recovery. Clinical and radiologic findings following ICH may assist rehabilitation specialists as they develop treatment goals, anticipate long-term patient care needs, and educate and train caregivers.
The present study provides a detailed account of neurocognitive outcome following minimal access ... more The present study provides a detailed account of neurocognitive outcome following minimal access subtemporal selective amygdalohippocampectomy (SAH) and establishes rates of neurocognitive decline in the largest sample to date. Use of a subtemporal surgical approach to SAH has been proposed to possibly reduce the risk for postoperative neurocognitive decline since lateral neocortical tissues is not resected and the temporal stem is preserved. The current study extends prior research with subtemporal SAH patients to include not only group level analyses but also analyses based on reliable change data. Neurocognitive comparisons are made between 47 patients that underwent subtemporal SAH. Statistical comparisons were made between neurocognitive performance at the group level and with use of reliable change scores. Approximately 75% of patients were seizure free postoperatively. At the group level, there were no significant postoperative changes. For the left SAH patients, reliable change scores demonstrated a decline in approximately one third of patients for memory, verbal intellect, and naming. Right SAH patients showed decline primarily in memory. These results indicated good seizure control following subtemporal SAH with greatest risk for neurocognitive decline following dominant SAH and best cognitive outcome following non-dominant SAH. Findings demonstrated the importance of reliable change analyses that make individual based comparisons and take into account measurement error. Despite preservation of the lateral neocortical tissue and the temporal stem, subtemporal SAH presents a risk for cognitive decline in a notable portion of patients.
... Squire, LR (1987). Memory and brain. New . ... Traumatic brain injury and temporal horn enlar... more ... Squire, LR (1987). Memory and brain. New . ... Traumatic brain injury and temporal horn enlargement: Correlates with tests of intelligence and memory. ...
Journal of the International Neuropsychological Society, 2004
Hypoxia damages multiple organ systems especially those with high oxygen utilization such as the ... more Hypoxia damages multiple organ systems especially those with high oxygen utilization such as the central nervous system. The purpose of this study was to compare the neuropathological and neuropsychological effects of hypoxia in patients with either carbon monoxide poisoning or obstructive sleep apnea. Neuroimaging revealed evidence of hippocampal atrophy in both groups although a linear relationship between hippocampal volume and memory performance was found only for selected tests and only in the sleep apnea group. There were significant correlations between hippocampal volume and performance on measures related to nonverbal/information processing. Generalized brain atrophy, as measured by the ventricle-to-brain ratio, was more common in the carbon monoxide poisoning group compared to the obstructive sleep apnea group. Performance on tests of executive function improved following treatment with nasal continuous positive airway pressure treatment in the obstructive sleep apnea group but there was no associated improvement in general intellectual function. We found that hypoxia due to obstructive sleep apnea and CO poisoning resulted in neuropathological changes and neuropsychological impairments. The observed group differences provide insight into the relationship between etiology of injury, neuropathological changes, and clinical presentation.
To examine the association between right frontal pole cortical thickness, social competence, and ... more To examine the association between right frontal pole cortical thickness, social competence, and cognitive proficiency in children participants with a history of chronic traumatic brain injury (TBI). Twenty-three children (65% male; M age = 12.8 years, SD = 2.3 years) at least 1 year post-injury (M = 3.3 years, SD = 1.7 years) were evaluated with the Cognitive Proficiency Index (CPI) from the Wechsler Intelligence Scale for Children, 4th Edition, and their caregiver completed the Child Behavior Checklist. Social competence was evaluated with the Social Competence and Social Problems subscales from the Child Behavior Checklist. Right frontal pole cortical thickness was calculated via FreeSurfer from high-resolution 3-dimensional T1 magnetic resonance imaging scans. Direct effect of right frontal pole cortical thickness on social competence was significant (β = 14.09, SE = 4.6, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01). Right frontal pole cortical thickness significantly predicted CPI (β = 18.44, SE = 4.9, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05), and CPI significantly predicted social competence (β = 0.503, SE = 0.17, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01). Findings were consistent with the hypothesized mediation model. The association between right frontal lobe cortical integrity and social competence in pediatric participants with chronic TBI may be mediated through cognitive proficiency.
Prior research has suggested an association between exposure to infectious disease and neurocogni... more Prior research has suggested an association between exposure to infectious disease and neurocognitive function in humans. While most of these studies have explored individual viral, bacterial, and even parasitic sources of infection, few have considered the potential neurocognitive burden associated with multiple infections. In this study, we utilized publically available data from a large dataset produced by the Centers for Disease Control and Prevention that included measures of neurocognitive function, sociodemographic variables, and serum antibody data for several infectious diseases. Specifically, immunoglobulin G antibodies for toxocariasis, toxoplasmosis, hepatitis A, hepatitis B, and hepatitis C, cytomegalovirus, and herpes 1 and 2 were available in 5662 subjects. We calculated an overall index of infectious-disease burden to determine if an aggregate measure of exposure to infectious disease would be associated with neurocognitive function in adults aged 20–59 years. The index predicted processing speed and learning and memory but not reaction time after controlling for age, sex, race-ethnicity, immigration status, education, and the poverty-to-income ratio. Interactions between the infectious-disease index and some sociodemographic variables were also associated with neurocognitive function. In summary, an index aggregating exposure to several infectious diseases was associated with neurocognitive function in young-to middle-aged adults.
Background: Helicobacter pylori (H. pylori) infection is associated with cogni-tive deficits in h... more Background: Helicobacter pylori (H. pylori) infection is associated with cogni-tive deficits in humans, an association potentially mediated or moderated by folate concentration or inflammation.
Materials and Methods: We used the National Health and Nutrition Examination Survey (NHANES) datasets to examine whether folate concentration or inflammation mediates or moderates the relationship between H. pylori and cognitive function. Models were performed using linear, Poisson, and zero-inflated Poisson regression, and we performed separate analyses for groups aged 20–59 and 60–90 years with sample sizes ranging from 700 to 1700.
Results: We did not find evidence of mediation in either age group. In the 20-to 59-year group, interactions between H. pylori and ferritin (p values ranging from .004 to .039) were associated with worse processing speed, better working memory, and worse reaction time. Interactions between H. pylori and fibrinogen (p values ranging from .023 to .045), C-reactive protein (CRP) (p = .023), and the inflammatory index (p = .045) were associated with worse processing speed. In 60-to 90-year-olds, H. pylori interacted with ferritin and the inflammatory index to predict fewer mathematical errors (p values of .036 and .023). Interactions with folate (p values of .016 and .006) and C-reactive protein (p values ranging from <.001 to .048) were inconsistent in directionality.
Conclusions: In this dataset, representative of the US population, inflammation and folate concentrations moderated but did not mediate the association between H. pylori seropositivity and cognition.
To determine the magnitude and time course of changes in the volume of brain and intracranial cer... more To determine the magnitude and time course of changes in the volume of brain and intracranial cerebrospinal fluid (CSF) spaces in patients who have sustained traumatic brain injury and to assess the relationship between these findings and long-term cognitive traumatic outcome. Axial intermediate and T2-weighted MR images of 123 patients with traumatic brain injury were quantified using a multispectral segmentation algorithm. Measurements were corrected for differences in age, sex, and head size using a previously reported normative database. Brain morphology was compared across groups formed on the basis of chronicity of injury. Cognitive functioning and severity of injury were statistically correlated with brain measurements. Time-dependent expansion of CSF spaces and decreases in brain volume were observed. Increases in ventricular CSF volume, particularly in the temporal horns and third ventricle, preceded subsequent changes in total brain and subarachnoid CSF. High and moderate ...
To present a normative database of hippocampal and temporal horn volume and to clarify the relati... more To present a normative database of hippocampal and temporal horn volume and to clarify the relationship between these measures and cognitive outcome in patients with traumatic brain injury. Ninety-six healthy volunteers and 94 patients with traumatic brain injury were examined with coronal intermediate and T2-weighted MR imaging. Multispectral segmentation and volume analyses were performed. The volumetry of the hippocampus and temporal horn was characterized in the control subjects. Volumetric measures in a group of patients with traumatic brain injury who had received MR imaging 3 months or less after injury were compared with measurements in other patients in the chronic phase of recovery. The relationship between neuropsychological testing and volumetric measures was analyzed with particular emphasis on the correlation between cognitive outcome and hippocampal and temporal horn volumes. No significant age group differences were found in the normative group from age 16 to 65. Lef...
PURPOSE: To present a normative volumetric database, spanning 5 decades of life, of cerebro- spin... more PURPOSE: To present a normative volumetric database, spanning 5 decades of life, of cerebro- spinal fluid, subarachnoid cerebrospinal fluid, total brain volume, total ventricular volume (com- ponent ventricular volumes of lateral, temporal horn, and third and fourth ventricles) and estimates of white and gray matter, based on a multispectral segmentation of brain MR. This database is presented as a reference
Advances in neuroimaging have greatly improved our understanding of stroke not only in the acute,... more Advances in neuroimaging have greatly improved our understanding of stroke not only in the acute, but also in the subacute and chronic stages of recovery. More recently developed magnetic resonance techniques such as diffusion and perfusion weighted imaging, as well as more traditional magnetic resonance and computed tomography studies allow clinicians to more accurately diagnosis stroke subtypes, optimize treatment, and predict prognosis. Although not widely utilized for clinical use, functional neuroimaging techniques have also been shown to be useful in terms of predicting prognosis and advancing our understanding of reorganization and recovery following stroke. Thus, neuroimaging in stroke may also be utilized to monitor response to both medical treatment as well as physical rehabilitation. The following is a review of current research relevant to the field of neuroimaging of stroke. We begin with a discussion of structural imaging techniques with the goal of familiarizing the r...
Latent infection from Toxoplasma gondii (T. gondii) is widespread worldwide and has been associat... more Latent infection from Toxoplasma gondii (T. gondii) is widespread worldwide and has been associated with cognitive deficits in some but not all animal models and in humans. We tested the hypothesis that latent toxoplasmosis is associated with decreased cognitive function in a large cross-sectional dataset, the National Health and Nutrition Examination Survey (NHANES). There were 4178 participants aged 20–59 years, of whom 19·1% had IgG antibodies against T. gondii. Two ordinary least squares (OLS) regression models adjusted for the NHANES complex sampling design and weighted to represent the US population were estimated for simple reaction time, processing speed and short-term memory or attention. The first model included only main effects of latent toxoplasmosis and demographic control variables, and the second added interaction terms between latent toxoplasmosis and the poverty-to-income ratio (PIR), educational attainment and raceethnicity. We also used multivariate models to assess all three cognitive outcomes in the same model. Although the models evaluating main effects only demonstrated no association between latent toxoplasmosis and the cognitive outcomes, significant interactions between latent toxoplasmosis and the PIR, between latent toxoplasmosis and educational attainment, and between latent toxoplasmosis and race-ethnicity indicated that latent toxoplasmosis may adversely affect cognitive function in certain groups.
Latent infection with the apicomplexan Toxoplasma gondii (Nicolle et Manceaux, 1908) has been ass... more Latent infection with the apicomplexan Toxoplasma gondii (Nicolle et Manceaux, 1908) has been associated with schizophrenia, bipolar disorder and self-harm behaviour. However, the potential relationship between T. gondii immunoglobulin G antibody (IgG) seropositivity and generalised-anxiety disorder (GAD) and panic disorder (PD) has not been investigated. The associations between serum reactivity to T. gondii and major depressive disorder (MDD), GAD and PD were evaluated in a total sample of 1 846 adult participants between the ages of 20 and 39 years from the United States Center for Disease Control’s National Health and Nutrition Examination Survey (NHANES). Approximately 16% of the overall sample was seropositive for T. gondii and 7% of the sample met criteria for MDD, 2% for GAD and 2% for PD. There were no significant associations between T. gondii IgG seroprevalence and MDD (OR = 0.484, 95% CI = 0.186–1.258), GAD (OR = 0.737, 95% CI = 0.218–2.490) or PD (OR = 0.683, 95% CI = 0.206–2.270) controlling for sex, ethnicity, poverty-to-income ratio and educational attainment. However, limited evidence suggested a possible association between absolute antibody titres for T. gondii and GAD and PD but not MDD. Toxoplasma gondii seroprevalence was not associated with MDD, GAD or PD within the context of the limitations of this study, although there may be an association of T. gondii serointensity with and GAD and PD, which requires further study.
A modification of the Fuld Object Memory Evaluation (FOME) was administered to 232 normally funct... more A modification of the Fuld Object Memory Evaluation (FOME) was administered to 232 normally functioning children in grades one through eight in a public school district in Phoenix, Arizona. The test was terminated once all 10 objects were successfully recalled by the child. Ceiling effects were observed as 226 out of 232 children (97.4%) recalled all 10 objects on or before the fourth trial. Ineffective reminders were rare. Ceiling effects were studied as a function of age and grade level. The information may be helpful when examining children with severe cognitive impairments or from different cultural backgrounds.
The purpose of this study was to assess the feasibility of utilizing low-current stimulation for ... more The purpose of this study was to assess the feasibility of utilizing low-current stimulation for F-wave generation, thereby avoiding the discomfort of repetitive supramaximal stimulation. We employed the same technique as is used for generating F waves in the conventional way, except for using a stimulating current that was just strong enough to evoke a motor response on the oscilloscope. This usually required a stimulus of about 10–15 mA at 0.2-ms duration. Both median nerves of 30 subjects were evaluated with this technique and with F waves generated by the conventional technique in the same subjects. Amplitudes were larger when using supramaximal current stimulation. However, there was no statistical difference between F-wave latencies, chronodispersion, and persistence (penetrance) elicited with maximal and low-current stimulation. This procedure should represent a significant improvement for patient comfort during electrodiagnostic procedures involving F-wave studies. Muscle Nerve 28: 82–86, 2003
Two studies were conducted to determine the frequency of processing speed difficulties relative t... more Two studies were conducted to determine the frequency of processing speed difficulties relative to estimates of other problem-solving abilities in children with and without traumatic brain injury (TBI). The two samples consisted of 213 normally functioning school-age children and 65 TBI children and 19 trauma controls. All children were administered the WISC-III/IV Vocabulary, Block Design, and Coding subtests. The frequency of children in each sample having a Coding subtest score of 3 or 4 scale points below the Vocabulary or Block Design score (whichever one was lower) was calculated. Using a 3-point scale difference, the presence of processing speed deficits relative to other cognitive abilities in the school sample was low (5.2%), and was equivalent to that demonstrated by trauma controls (5.3%). However, in the TBI sample, 18 out of 65 TBI patients (27.7%) showed this same pattern. Using a 4-point discrepancy scale, 3.3% of normal children and 16.9% of TBI children showed this pattern. The frequency of this pattern increased with severity of TBI, using two different but related classification systems. These preliminary findings require cross validation in a larger sample before definite conclusions can be reached.
... ERIN D. BIGLER, C. STERLING JOHNSON, CAROL ANDERSON, AND SHAWN D. GALE Department of Psycholo... more ... ERIN D. BIGLER, C. STERLING JOHNSON, CAROL ANDERSON, AND SHAWN D. GALE Department of Psychology, Brigham Young University, Provo ... of the MRI in the normal and medical control with autopsy reports (Ho, Roessmann, Straumfjord, &amp; Monroe, 1980; Dekaban &amp; ...
Primary intracerebral haemorrhage (ICH) is a common and devastating disorder that often results i... more Primary intracerebral haemorrhage (ICH) is a common and devastating disorder that often results in long-term disability. This review examines the literature on predictors of survival and long-term functional outcome after ICH. Medical literature review. Numerous clinical and radiologic variables have been shown to be associated with survival and functional recovery following ICH. These include patient age and gender, lesion size and location, initial level of consciousness, presence of intraventricular haemorrhage, hydrocephalus, and mass effect. Studies have employed a variety of outcome measures including survival and functional recovery. Clinical and radiologic findings following ICH may assist rehabilitation specialists as they develop treatment goals, anticipate long-term patient care needs, and educate and train caregivers.
The present study provides a detailed account of neurocognitive outcome following minimal access ... more The present study provides a detailed account of neurocognitive outcome following minimal access subtemporal selective amygdalohippocampectomy (SAH) and establishes rates of neurocognitive decline in the largest sample to date. Use of a subtemporal surgical approach to SAH has been proposed to possibly reduce the risk for postoperative neurocognitive decline since lateral neocortical tissues is not resected and the temporal stem is preserved. The current study extends prior research with subtemporal SAH patients to include not only group level analyses but also analyses based on reliable change data. Neurocognitive comparisons are made between 47 patients that underwent subtemporal SAH. Statistical comparisons were made between neurocognitive performance at the group level and with use of reliable change scores. Approximately 75% of patients were seizure free postoperatively. At the group level, there were no significant postoperative changes. For the left SAH patients, reliable change scores demonstrated a decline in approximately one third of patients for memory, verbal intellect, and naming. Right SAH patients showed decline primarily in memory. These results indicated good seizure control following subtemporal SAH with greatest risk for neurocognitive decline following dominant SAH and best cognitive outcome following non-dominant SAH. Findings demonstrated the importance of reliable change analyses that make individual based comparisons and take into account measurement error. Despite preservation of the lateral neocortical tissue and the temporal stem, subtemporal SAH presents a risk for cognitive decline in a notable portion of patients.
... Squire, LR (1987). Memory and brain. New . ... Traumatic brain injury and temporal horn enlar... more ... Squire, LR (1987). Memory and brain. New . ... Traumatic brain injury and temporal horn enlargement: Correlates with tests of intelligence and memory. ...
Journal of the International Neuropsychological Society, 2004
Hypoxia damages multiple organ systems especially those with high oxygen utilization such as the ... more Hypoxia damages multiple organ systems especially those with high oxygen utilization such as the central nervous system. The purpose of this study was to compare the neuropathological and neuropsychological effects of hypoxia in patients with either carbon monoxide poisoning or obstructive sleep apnea. Neuroimaging revealed evidence of hippocampal atrophy in both groups although a linear relationship between hippocampal volume and memory performance was found only for selected tests and only in the sleep apnea group. There were significant correlations between hippocampal volume and performance on measures related to nonverbal/information processing. Generalized brain atrophy, as measured by the ventricle-to-brain ratio, was more common in the carbon monoxide poisoning group compared to the obstructive sleep apnea group. Performance on tests of executive function improved following treatment with nasal continuous positive airway pressure treatment in the obstructive sleep apnea group but there was no associated improvement in general intellectual function. We found that hypoxia due to obstructive sleep apnea and CO poisoning resulted in neuropathological changes and neuropsychological impairments. The observed group differences provide insight into the relationship between etiology of injury, neuropathological changes, and clinical presentation.
To examine the association between right frontal pole cortical thickness, social competence, and ... more To examine the association between right frontal pole cortical thickness, social competence, and cognitive proficiency in children participants with a history of chronic traumatic brain injury (TBI). Twenty-three children (65% male; M age = 12.8 years, SD = 2.3 years) at least 1 year post-injury (M = 3.3 years, SD = 1.7 years) were evaluated with the Cognitive Proficiency Index (CPI) from the Wechsler Intelligence Scale for Children, 4th Edition, and their caregiver completed the Child Behavior Checklist. Social competence was evaluated with the Social Competence and Social Problems subscales from the Child Behavior Checklist. Right frontal pole cortical thickness was calculated via FreeSurfer from high-resolution 3-dimensional T1 magnetic resonance imaging scans. Direct effect of right frontal pole cortical thickness on social competence was significant (β = 14.09, SE = 4.6, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01). Right frontal pole cortical thickness significantly predicted CPI (β = 18.44, SE = 4.9, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05), and CPI significantly predicted social competence (β = 0.503, SE = 0.17, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01). Findings were consistent with the hypothesized mediation model. The association between right frontal lobe cortical integrity and social competence in pediatric participants with chronic TBI may be mediated through cognitive proficiency.
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Papers by Shawn D Gale
Materials and Methods: We used the National Health and Nutrition Examination Survey (NHANES) datasets to examine whether folate concentration or inflammation mediates or moderates the relationship between H. pylori and cognitive function. Models were performed using linear, Poisson, and zero-inflated Poisson regression, and we performed separate analyses for groups aged 20–59 and 60–90 years with sample sizes ranging from 700 to 1700.
Results: We did not find evidence of mediation in either age group. In the 20-to 59-year group, interactions between H. pylori and ferritin (p values ranging from .004 to .039) were associated with worse processing speed, better working memory, and worse reaction time. Interactions between H. pylori and fibrinogen (p values ranging from .023 to .045), C-reactive protein (CRP) (p = .023), and the inflammatory index (p = .045) were associated with worse processing speed. In 60-to 90-year-olds, H. pylori interacted with ferritin and the inflammatory index to predict fewer mathematical errors (p values of .036 and .023). Interactions with folate (p values of .016 and .006) and C-reactive protein (p values ranging from <.001 to .048) were inconsistent in directionality.
Conclusions: In this dataset, representative of the US population, inflammation and folate concentrations moderated but did not mediate the association between H. pylori seropositivity and cognition.
in some but not all animal models and in humans. We tested the hypothesis that latent toxoplasmosis is associated with
decreased cognitive function in a large cross-sectional dataset, the National Health and Nutrition Examination Survey
(NHANES). There were 4178 participants aged 20–59 years, of whom 19·1% had IgG antibodies against T. gondii. Two
ordinary least squares (OLS) regression models adjusted for the NHANES complex sampling design and weighted to
represent the US population were estimated for simple reaction time, processing speed and short-term memory or attention.
The first model included only main effects of latent toxoplasmosis and demographic control variables, and the second added
interaction terms between latent toxoplasmosis and the poverty-to-income ratio (PIR), educational attainment and raceethnicity.
We also used multivariate models to assess all three cognitive outcomes in the same model. Although the models
evaluating main effects only demonstrated no association between latent toxoplasmosis and the cognitive outcomes,
significant interactions between latent toxoplasmosis and the PIR, between latent toxoplasmosis and educational
attainment, and between latent toxoplasmosis and race-ethnicity indicated that latent toxoplasmosis may adversely affect
cognitive function in certain groups.
bipolar disorder and self-harm behaviour. However, the potential relationship between T. gondii immunoglobulin G antibody
(IgG) seropositivity and generalised-anxiety disorder (GAD) and panic disorder (PD) has not been investigated. The associations
between serum reactivity to T. gondii and major depressive disorder (MDD), GAD and PD were evaluated in a total sample
of 1 846 adult participants between the ages of 20 and 39 years from the United States Center for Disease Control’s National Health
and Nutrition Examination Survey (NHANES). Approximately 16% of the overall sample was seropositive for T. gondii and 7% of
the sample met criteria for MDD, 2% for GAD and 2% for PD. There were no significant associations between T. gondii IgG seroprevalence
and MDD (OR = 0.484, 95% CI = 0.186–1.258), GAD (OR = 0.737, 95% CI = 0.218–2.490) or PD (OR = 0.683, 95%
CI = 0.206–2.270) controlling for sex, ethnicity, poverty-to-income ratio and educational attainment. However, limited evidence
suggested a possible association between absolute antibody titres for T. gondii and GAD and PD but not MDD. Toxoplasma gondii
seroprevalence was not associated with MDD, GAD or PD within the context of the limitations of this study, although there may be
an association of T. gondii serointensity with and GAD and PD, which requires further study.
Materials and Methods: We used the National Health and Nutrition Examination Survey (NHANES) datasets to examine whether folate concentration or inflammation mediates or moderates the relationship between H. pylori and cognitive function. Models were performed using linear, Poisson, and zero-inflated Poisson regression, and we performed separate analyses for groups aged 20–59 and 60–90 years with sample sizes ranging from 700 to 1700.
Results: We did not find evidence of mediation in either age group. In the 20-to 59-year group, interactions between H. pylori and ferritin (p values ranging from .004 to .039) were associated with worse processing speed, better working memory, and worse reaction time. Interactions between H. pylori and fibrinogen (p values ranging from .023 to .045), C-reactive protein (CRP) (p = .023), and the inflammatory index (p = .045) were associated with worse processing speed. In 60-to 90-year-olds, H. pylori interacted with ferritin and the inflammatory index to predict fewer mathematical errors (p values of .036 and .023). Interactions with folate (p values of .016 and .006) and C-reactive protein (p values ranging from <.001 to .048) were inconsistent in directionality.
Conclusions: In this dataset, representative of the US population, inflammation and folate concentrations moderated but did not mediate the association between H. pylori seropositivity and cognition.
in some but not all animal models and in humans. We tested the hypothesis that latent toxoplasmosis is associated with
decreased cognitive function in a large cross-sectional dataset, the National Health and Nutrition Examination Survey
(NHANES). There were 4178 participants aged 20–59 years, of whom 19·1% had IgG antibodies against T. gondii. Two
ordinary least squares (OLS) regression models adjusted for the NHANES complex sampling design and weighted to
represent the US population were estimated for simple reaction time, processing speed and short-term memory or attention.
The first model included only main effects of latent toxoplasmosis and demographic control variables, and the second added
interaction terms between latent toxoplasmosis and the poverty-to-income ratio (PIR), educational attainment and raceethnicity.
We also used multivariate models to assess all three cognitive outcomes in the same model. Although the models
evaluating main effects only demonstrated no association between latent toxoplasmosis and the cognitive outcomes,
significant interactions between latent toxoplasmosis and the PIR, between latent toxoplasmosis and educational
attainment, and between latent toxoplasmosis and race-ethnicity indicated that latent toxoplasmosis may adversely affect
cognitive function in certain groups.
bipolar disorder and self-harm behaviour. However, the potential relationship between T. gondii immunoglobulin G antibody
(IgG) seropositivity and generalised-anxiety disorder (GAD) and panic disorder (PD) has not been investigated. The associations
between serum reactivity to T. gondii and major depressive disorder (MDD), GAD and PD were evaluated in a total sample
of 1 846 adult participants between the ages of 20 and 39 years from the United States Center for Disease Control’s National Health
and Nutrition Examination Survey (NHANES). Approximately 16% of the overall sample was seropositive for T. gondii and 7% of
the sample met criteria for MDD, 2% for GAD and 2% for PD. There were no significant associations between T. gondii IgG seroprevalence
and MDD (OR = 0.484, 95% CI = 0.186–1.258), GAD (OR = 0.737, 95% CI = 0.218–2.490) or PD (OR = 0.683, 95%
CI = 0.206–2.270) controlling for sex, ethnicity, poverty-to-income ratio and educational attainment. However, limited evidence
suggested a possible association between absolute antibody titres for T. gondii and GAD and PD but not MDD. Toxoplasma gondii
seroprevalence was not associated with MDD, GAD or PD within the context of the limitations of this study, although there may be
an association of T. gondii serointensity with and GAD and PD, which requires further study.